Guidance for Parts Manufacturer Approval of Turbine Engine and Auxiliary Power Unit Parts under Test and Computation

AC 33-8 8/19/09 Appendix 1 APPENDIX 1. FAILURE MODES AND EFFECTS ASSESSMENT 1. A failure modes and effects assessment is a qualitative process, independent of failure rates and probabilities, by which each failure mode of a part in the engine system is analyzed. Some top-level functions typically considered in an engine failure modes and effects assessment are: • Maintaining structural integrity, including allowed overspeed and overtemperature exceedances; • Providing thrust or power; • Operating in inclement weather; • Providing customer bleed, power extraction, or both; and • Meeting fuel consumption, exhaust gas temperature, vibration, emission or noise limits.

2. Each system and subsystem of the engine is broken down into its basic functions using a functional block diagram consistent with the Air Transport Association policy for identification and definition of systems.

3. The functional block diagram defines each system and subsystem, and all their functions, in the turbine engine. The experienced safety engineer performing the analysis determines the part- to-part and part-to-system influences in both directions (input and output). The process flow is shown in figure A1.1 below: Figure A1.1. Process Flow Diagram Identify parts Determine functions Determine input within the system provided by the part functions from other being analyzed engine systems being analyzed Determine consequence of failure to provide the desired function by design intent Determine outcome on part, Categorize part by outcomes engine system, and the engine in Tables 1 and 2 of this AC

AC 33-8 8/19/09 Appendix 1 4. The part categorization process is built around the fundamental understanding of the part function and its potential effects on physically or functionally mating parts or both. The fundamental premise in the categorization process, and in the physical operation and function of the turbine engine, is system interactions.

a. System interactions are influences a part, or a set of parts, can have on the turbine engine, propulsion system, or aircraft through form, fit, or function. These influences may extend beyond the component being classified, may be direct or indirect, and may develop immediately or over time. Characteristics of these influences include: (1) Direct influences, which are form and fit. These influences are based on physical contact or interface clearances between adjacent parts.

(2) Indirect influences, which are functional in nature. These influences are not based on physical contact, but may be aerodynamic, thermal, or vibratory.

5. The interactions where the consequence of failure is the furthest from the cause are the most difficult to identify. Many fundamental relationships in part interactions and subsequent system effects exist. Figure A1.2 below provides four examples.

Figure A1.2. Part Interaction Considerations

Indirect Effect

Part Interaction

Stage 1 HPT Effective HPC press. Stall margin Stall at limiting Nozzle area/flow ratio consumption condition

Considerations

•Fluid interactions • Air, fuel, oil

Indirect Effect

•Direct interactions Fuel Pump Fuel flow Fuel to Starting Altitude re-light • Mechanical Impeller schedule Combustor characteristic capability loading • Aero loading • Contact/wear

Time Relationship

• Chemical Critical part Stage 2 HPT Cooling flow to Purge flow Hot gas temperature & •Indirect interactions Nozzle rotor level ingestion life • Vibration

Direct Effect • Acoustical

Loads and Local dovetail Dovetail or slot • Primary air Rotor Blade moments on LLP life impact loading bottom life disk • Secondary air • Control system • Structural dynamics • Sensor systems

AC 33-8 8/19/09 Appendix 2 APPENDIX 2. TEMPLATES 1. This appendix provides 17 templates, listed in Table A2-1 below. The FAA selected them based on what we found applicants were typically submitting for complex turbine engine part PMA approval. These templates will aid applicants in identifying the technical elements and regulatory requirements they should consider when developing their test and substantiation plans. Applicants must ensure that any additional technical criteria or regulatory requirements are met for their specific proposed PMA part. Each template is subdivided into the following sections: a. Section 1 - Part functional capability, which is the action the part is designed to perform in the engine.

b. Section 2 - Part shape, size, dimensions, and other physical, measurable parameters; interconnectivity with an engine integral part or system; or both.

c. Section 3 – Part materials and processes – properties.

d. Section 4 – Part materials and processes – processing.

e. Section 5 - Applicable analyses.

f. Section 6 - Applicable testing.

g. Section 7 - Applicable regulatory requirements.

2. Sections 1 through 5 are divided into the following five columns: a. Column 1 is the section number.

b. Columns 2 and 3 identify part characteristics to be evaluated to support the functional design intent of the type design part.

c. Column 4 identifies typical areas applicants should evaluate for potential part and system failure modes.

d. Column 5 is used to identify a combination of actions and criteria for risk mitigation and control when a corresponding failure mode is identified in column 4.

3. Section 7 of the templates identifies the part 33 (Amendments 1-20 inclusive) airworthiness requirements applicable to turbine engines. However, not all engine certification bases include the same requirements.

4. If a template is not available for a particular part, the applicant can create or modify another as necessary. For example, although templates specific to APU parts are not provided, the

AC 33-8 8/19/09

Appendix 2

applicant may use the templates for similar APU parts and revise the regulatory section to reflect the requirements of TSO C77.

Table A2-1. Available Templates

Template Part Name

Number

1 O-Rings

2 Embedded elastomer seals

3 Combustor

4 Low pressure turbine blade

5 Turbine vane cooled

6 Turbine vane un-cooled

7 Shaft

8 Roller bearing

9 Ball bearing

10 Gear

11 Compressor vane

12 Compressor blade

13 Static air seal

14 Variable stator vane lever arms

15 Bushings

16 Turbine blade cooled

17 Fuel filter

8/19/09

Cross-Section Mold Line/Flash Shape May Vary Width Outer Diameter

Template #1: O-Rings

(all features may not be applicable)

Nomenclature for Generic Component Features

Inner Diameter AC 33-8 Appendix 2 This template deals with non-standard seals which are typically procured under a TC holder part number. If the part is listed as a standard part and can be procured commercially these requirements do not apply.

8/19/09

Dimensional process control Verify certificates Verify capability exceeds expected duty cycle Verify capability exceeds expected duty cycle Verify chemical compatibility with TC holder approved fluids. Dimensional process control and inspection Dimensional process control Dimensional process control and inspection Verify part is tolerant to variation Control of manufacturing and inspection processes • • • • • • • • • • Risk Mitigation and Control Risk Mitigation and Control Installation into assembly Ability to perform sealing function Ensure compression is within the allowable range Mechanical/Functional, failure due to variation from nominal Dimensionally within limits Base material certifications Recommended limits by manufacturer Recommended limits by manufacturer • • • • • • • • Part and System Failure Modes Part and System Failure Modes Physical dimension Actual material used in part Maximum and minimum temperatures Compatibility with TC holder approved fluids in applicable system.

Key Characteristics • • • • Inside diameter Outside diameter Cross sectional size Actual surface conditions Design compression/expansion set/spring back Variance-Fluctuations in measurements Key Characteristics • • • • • • • Characteristic Critical to Part Functionality Static Size Material Temperature limits Chemical resistance Characteristic Critical to Part Functionality Boundary dimensions Surface finish Fit-up dimensions Tolerance AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4

8/19/09

Process control (melt control, cleanliness) Process control and sequencing Process control Verify adequate control of processes and parameters • • • • Risk Mitigation and Control Perform analysis at relevant operating conditions Verify part is tolerant to variation Material selection Process control Material selection Process control Adequate material properties Operational effects accounted for Verify adequate environmental properties • • Risk Mitigation and Control Risk Mitigation and Control • • • • • • • Inadequate material properties Improper thickness and excess flash Inadequate final part form, or defect “escape” Part and System Failure Modes • • • Inadequate part life due to analysis under-predicting part temperature, mechanical stress, chemical resistance Inadequate part function due to variation Poor mechanical or environmental resistance properties Consistent properties within operating parameters Low material properties Physical deterioration from Oxidation/Corrosion/chemical attack Property reduction due to extreme temperatures 19 • • Part and System Failure Modes Part and System Failure Modes • • • • • Purity Proper form and texture Inspection Manufacturing Process Substantiation and Control (RSS,RSA,ESA, etc) Key Characteristics • • • • • Temperatures Sealing ability Proper contact pressures Engine operation characteristics Key Characteristics • • • • Major elements - % Variation Impurities Density Coefficient of thermal expansion Melting Point Modulus Hardness/Durometer hardness Oxidation Temperature range Corrosion Chemical resistance Age related material property change Key Characteristics • • • • • • • • • • • • Characteristic Critical to Part Functionality Raw material processing Surface treatment Process sequencing and Significant Process Identification and Substantiation Characteristic Critical to Part Functionality Operating conditions Variation Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical properties Environmental resistance AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 Section 4 – Part Materials and Processes - Processing Section/Number 4-1 4-2 4-3 Section 5 – Analysis Section/Number 5-1 5-2

8/19/09

Perform adequate component and/or engine testing Engine testing • • Risk Mitigation and Control Excessive leakage Excessive Vibration Excessive leakage Difficult to disassemble after operation • • • • Part and System Failure Modes Comments ICAs including on-wing inspection requirements and on-wing limits for leakage Could be affected Engine vibration response Leakage Vibration signature Abnormal wear Environmental testing to hot and cold limitations for the engine. Thermal conditions at the “O” ring seal installed location Durability/replacement interval(s)/shelf life, etc, if applicable?

Key Characteristics • • • • • • General – Characteristic Critical to Part Functionality Durability Operability and performance the engine Applicable 14 CFR Part 33 Regulatory Requirements Subpart A 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4.

AC 33-8 Appendix 2 Section 6 – Testing Section/Number 6-1 6-2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

No fluid leakage Leakage limits Leakage limits Leakage limits Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected supercharger rotors Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

AC 33-8 Appendix 2

8/19/09

Leakage limits Leakage limits Could be affected Could be affected Could be affected ingestion) of ingestion) (Weight changes) mode Subpart E – Design and Construction; Turbine Aircraft Engines 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Puller Feature

Elastomeric Seal (Lip)

(all features may not be applicable)

Nomenclature for Generic Component Features

Template #2: Embedded Elastomer Seals

Seal Diameter

AC 33-8 Appendix 2 This template deals with non-standard seals which are typically procured under an OEM part number. If the part is listed as a standard part and can be procured commercially, these requirements do not apply.

8/19/09

Dimensional process control Process control Verify capability exceeds expected duty cycle Surface dimensional process control Verify acceptable wear Verify chemical compatibility with approved engine fluids. Dimensional process control and inspection Dimensional process control Dimensional process control and inspection Verify part is tolerant to variation Control of manufacturing and inspection processes • • • • • • • • • • • Risk Mitigation and Control Risk Mitigation and Control Installation into assembly Ability to perform sealing function Ensure compression is within the allowable range Mechanical/Functional, failure due to variation from nominal Dimensions are within limits Base material certifications Recommended limits by manufacturer Recommended limits by manufacturer • • • • • • • • Part and System Failure Modes Part and System Failure Modes Physical dimension of seal and carrier Actual material used in part Maximum and minimum temperatures List of chemicals which the material is compatible with Key Characteristics • • • • Hole locations Inside contour Outside contour Cross sectional size of elastomer Thickness of carrier Actual surface conditions Design compression/expansion Variance-fluctuations in measurements Parallelism of carrier Key Characteristics • • • • • • • • • Characteristic Critical to Part Functionality Static size Material Temperature limits Chemical resistance Characteristic Critical to Part Functionality Boundary dimensions Surface finish Fit-up dimensions Tolerance AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4

8/19/09

Process control (melt control, cleanliness) Process control and sequencing Process control Verify adequate control of processes and parameters • • • • Risk Mitigation and Control Perform analysis at relevant operating conditions Verify part is tolerant to variation • • Risk Mitigation and Control Material selection Process control Material selection Process control Adequate material properties Operational effects accounted for Verify adequate environmental properties Verify chemical compatibility with approved engine fluids.

Risk Mitigation and Control • • • • • • • • Inadequate material properties Improper thickness and excess flash Inadequate final part form, or defect “escape” Part and System Failure Modes • • • Inadequate part life due to analysis under-predicting part temperature, mechanical stress, chemical resistance Inadequate part function due to variation Poor mechanical or environmental resistance properties Consistent properties within operating parameters Low material properties Physical deterioration from Oxidation/Corrosion/chemical attack Property reduction due to extreme temperatures 25 • • Part and System Failure Modes Part and System Failure Modes • • • • • Purity Proper form and texture Inspection Manufacturing Process Substantiation and Control (RSS,RSA,ESA, etc) Key Characteristics • • • • • Temperatures Sealing ability Proper contact pressures Location of flange surfaces Engine operation characteristics Key Characteristics • • • • • Major elements - % variation Impurities Density Coefficient of thermal expansion Melting point Modulus Surface hardness Oxidation Temperature range Corrosion Chemical resistance Key Characteristics • • • • • • • • • • • Characteristic Critical to Part Functionality Operating conditions Variation Characteristic Critical to Part Functionality Raw material processing Surface treatment Process sequencing and Significant Process Identification and Substantiation Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical properties Environmental resistance AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 Section 4 – Part Materials and Processes - Processing Section/Number 4-1 4-2 4-3 Section 5 – Analysis Section/Number 5-1 5-2

8/19/09

Perform adequate component and/or engine testing Engine testing • • Risk Mitigation and Control Comments ICAs including on-wing inspection requirements and on-wing limits for leakage Adequate sealing required throughout engine operating envelope. No fluid leakage Excessive vibration Excessive leakage Excessive vibration Difficult to disassemble after operation • • • • Part and System Failure Modes Could be affected Could be affected Could be affected Could be affected Could be affected Engine vibration response Leakage Vibration signature Abnormal wear on affected parts Key Characteristics • • • • General – Characteristic Critical to Part Functionality Durability Operability and performance the engine Applicable 14 CFR Part 33 Regulatory Requirements Subpart A 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8.

AC 33-8 Appendix 2 Section 6 – Testing Section/Number 6-1 6-2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Leakage limits Leakage limits Could be affected Could be affected Could be affected supercharger rotors ingestion) of ingestion) Subpart B – Design and Construction; General 33.21 Engine Cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress Analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety Analysis 33.76 Bird Ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.

AC 33-8 Appendix 2

8/19/09

Leakage limits Leakage limits Could be affected Could be affected Could be affected (Weight changes) mode Subpart E – Design and Construction; Turbine Aircraft Engines 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Template #3: Combustor

(all features may not be applicable)

Nomenclature for Generic Component Features

AC 33-8 Appendix 2

8/19/09

Surface dimensional process control Surface dimensional process control Cooling and dilution hole dimensional process control Burner rig testing Resonance avoidance at steady state operation with margin Verify capability exceeds expected utilization Dimensional process control and inspection Burner rig testing Dimensional process control Burner rig testing Surface dimensional process control Risk Mitigation and Control • • • • • • Risk Mitigation and Control • • • • • Operability effects Emissions Turbine airfoils durability Over-temperature/dysfunction Emissions Improper temperature profile: over-temperature/dysfunction of downstream airfoils Static structure malfunction Crack growth from LCF or Creep – Rupture Emissions effects Combustor exit profile effects (pattern factor) Lean blowout Rumble or combustion Instability Durability ID/OD airflow distribution Lean blowout Durability Part and System Failure Modes • • • • • • • • Part and System Failure Modes • • • • • • • • As-cast surfaces Machined surfaces Inner and outer wall contours Nozzle area Total flow rate Individual nozzle swirler/heatshield flow rate ID/OD profile Static pressure distribution Combustor hood locating pins Geometry Cooling Material mechanical/metallurgical/physical properties Key Characteristics • • • • • • • • • • • • Profile and length Axial location of forward and aft face Functional fits at interfaces Part/assembly locating features (axial, radial and tangential) Air sealing surfaces Cooling and dilution holes Fuel nozzle location Cooling hole location Leading edge profile Radial location Cooling hole pattern Size Key Characteristics • • • • • • • • • • • • Characteristic Critical to Part Functionality Weight Profile Cooling/Dilution air utilization Structural strength Creep, LCF, fracture toughness, tensile overload capability Characteristic Critical to Part Functionality Inner and outer shells Hood Fuel nozzle swirlers AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3

8/19/09

Dimensional process control Verify part is tolerant to variation Control of manufacturing and inspection processes Risk Mitigation and Control • • • Acceptable stresses and frequencies Adequate material properties Operational effects accounted for Relevant properties are used Verify that grain orientation or low angle boundaries are accounted for Process control and inspection Material selection Master heat and process control Acceptable weight Acceptable stresses Combustor “fit” in hot condition Verify adequate environmental properties Risk Mitigation and Control • • Verify: • • • Verify: • • • • • • • Emissions Durability Mechanical/Functional, failure due to vibration from nominal Part and System Failure Modes • • • Poor mechanical or environmental properties Poor TBC adherence Excessive weight Excessive thermal stresses Interference with surrounding hardware Excessive strain-controlled stress Undesirable natural frequency Low material properties, dysfunction Material capability consumed in operation Material property reduction due to excessive grain angle or low angle boundaries, cast panel dysfunction Cracking from oxidation/corrosion pitting, dysfunction Part and System Failure Modes • • • • • • • • • • • Profile Cooling pin/fin size and location Variance-Fluctuations in measurements Measurement gauge repeatability and reliability Major elements - % variation Impurities Density Coefficient of thermal expansion Refractive Index (x-rays) Modulus (vs. grain orientation) Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF) Long term metallurgical stability Grain Structure (size, shape, flow, boundaries, gamma prime size and volume fraction) Low angle boundaries Directional properties Hardness Melting Point Crack propagation rate Oxidation, corrosion, erosion, fretting resistance Elevated temperature (creep, diffusion, ageing, temp. gradients) FOD resistance Key Characteristics • • • • Key Characteristics • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Cast panels Tolerance Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Cast structure Environmental resistance AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-4 2-5 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5

8/19/09

Process control (mold setup, casting process, and filtration) Process control and sequencing Process control and sequencing Risk Mitigation and Control • • • Control of chemistry and application process Verify thermal-mechanical compatibility with base material Control of chemistry and application process Verify part is tolerant to missing TBC No high TBC temperatures that accelerate spalling Risk Mitigation and Control • • • • • Crack growth from inclusion or porosity Poor coating adhesion, corrosion and oxidation Incorrect Gamma Prime size/spacing leading to low material properties Part and System Failure Modes • • • LCF property reduction due to poor coating selection/requirements, panel cracking Cracking from oxidation/corrosion pitting High thermal stresses or part temperature, swirler and panel dysfunction Part and System Failure Modes • • • Inclusions and porosity Internal surface cleanliness Time @ temperature and ramp rates Manufacturing sequence Atmosphere Key Characteristics • • • • • Coverage and thickness Long term stability Oxidation and corrosion resistance Coating material composition and density Thermal conductivity (coefficient of thermal expansion) Coverage and thickness uniformity Coating and diffusion zone microstructure Adhesion Oxidation Resistance to spalling, sintering and erosion Hardness Residual Stress Stripping requirements Bonding (Interface Contamination) Compatibility with base material/other coatings Key Characteristics • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Casting cleanliness Heat treatment Characteristic Critical to Part Functionality Environmental coating Thermal barrier coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-6 3-7 Section 4 – Part Materials and Processes - Processing Section/Number 4-1 4-2

8/19/09

Correct sequencing of braze or weld cycles in the process Process control Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Risk Mitigation and Control • • • • • • Perform analysis at relevant operating conditions Risk Mitigation and Control • Material property reduction Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, dysfunction Part and System Failure Modes • • • • Compressor operability Turbine airfoil durability Inadequate part life due to analysis over-predicting the swirler cooling effectiveness Part and System Failure Modes • • • Weld or braze strength Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitates, gamma prime and volume fraction Porosity Diffusion zone (brazing) Heat affected zone (welding) Penetration (welding) Excess braze allowance Filler metal selection Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS, RSA, ESA, etc) Key Characteristics Effect on base material properties, based on the following: • • • • • • • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Flow path temperatures, pressures, and velocities Nozzle area Exit profile Secondary flow circuit Swirler cooling flow Key Characteristics • • • • • Characteristic Critical to Part Functionality Welding and brazing Material removal – Non traditional (EDM, ECM, Laser, Water-Jet, etc.) and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and Significant Process Identification and Substantiation Characteristic Critical to Part Functionality Operating conditions Swirler cooling AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/Number 4-3 4-4 4-5 4-6 Section 5 – Analysis Section/Number 5-1 5-2

8/19/09

Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman Diagram Use applicable properties Use applicable dA/dN curve Predict K using expected defect size Perform analysis with predicted TBC loss Risk Mitigation and Control • • • • • • • Risk Mitigation and Control Using incorrect properties Failing to address the ‘key characteristics’ Combustor resonant vibration, cracking, dysfunction Combustor rupture cracking, dysfunction Crack growth from defect High thermal stress or part temperature, dysfunction Part and System Failure Modes Inadequate part life due to analysis • • • • • • Part and System Failure Modes Temperature effects Multi-axial effects Hold time effects Mean stress effects Notch effects Coating effects Mesh size Temperature effects Vibration and mean stress effects Temperature effects Material thickness effects Temperature effects Threshold stress intensity Crack growth rate Part temperature Thermal stress Fatigue Corrosion (hot and cold) Erosion Stress rupture Tensile strength Cooling Effectiveness Microstructure Creep Hot corrosion Tensile strength Smoke, HC, CO, NoX Key Characteristics • • • • • • • • • • • • • • • • Key Characteristics • • • • • • • • • • • Characteristic Critical to Part Functionality LCF/TMF life analysis HCF life analysis Creep and rupture life analysis Fracture mechanics Tolerance to missing TBC Characteristic Critical to Part Functionality Durability Over-temperature Emissions AC 33-8 Appendix 2 Section 5 – Analysis Section/Number 5-3 5-4 5-5 5-6 5-7 Section 6 – Testing Section/Number 6-1 6-2 6-3

8/19/09

Comments ICAs including on-wing inspection requirements and on-wing limits Could be affected Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

In-flight relighting Timed accels Combustor part release – downstream effects Combustor durability and starting capability Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35.

AC 33-8 Appendix 2

8/19/09

Combustor in-service inspection limits Could be affected Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Seal Knives Attachment or Dovetail Platform

(all features may not be applicable)

Nomenclature for Generic Component Features

Template #4: Low Pressure Turbine Blade

Airfoil Cross Notch/Cross Shroud

AC 33-8 Appendix 2

8/19/09

Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Risk Mitigation and Control Surface dimensional process control Surface dimensional process control Control damper seating with blade and/or disk • • Verify capability exceeds expected utilization Low flow: blade over-temperature/dysfunction High flow: reduced rotor cavity purge/ingestion/part dysfunction Poor distribution of cooling air: over-temperature, and existing bench flow limits not valid Blade separation from tensile overload Crack growth from LCF or creep – rupture Loss of tip fatigue strength from rubbing Part and System Failure Modes Dovetail/attachment and disk loading-dysfunction Dovetail/attachment and disk loading-dysfunction • • • Blade vibration: Blade or disk dovetail cracking Blade resonant vibration, cracking, dysfunction • • • As-cast surfaces Machined surfaces As-cast surfaces Machined surfaces Mass/density distribution Total flow rate Individual circuit-cavity flow rate Flow distribution Static pressure distribution Discharge pressure at showerhead, relative to turbine gas flow pressure Damper fit to blade Damping ratio Blade natural frequencies Vibration stress distribution Cycles to failure demonstration Vibration test set-up and execution criteria, i.e., establishing parameters for blade holding, loading, excitation modes determination, and excitation sensing techniques Blade geometry Blade cooling Material mechanical/metallurgical/physical properties Blade cleaning requirements/effectiveness (internal passages-intergranular attack) Key Characteristics • • • • • • • • • • • • • • • • • • • • Axial Tangential Radial Characteristic Critical to Part Functionality Weight Moment of weight - center of gravity • • • Cooling air utilization (If cooled) Vibration damping Vibration characteristics (HCF Capability) Creep, LCF, fracture toughness, tensile overload capability AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5 1-6

8/19/09

Verify part is tolerant to variation Control of manufacturing and inspection processes Risk Mitigation and Control Dimensional process control and inspection Dimensional process control Surface dimensional process control Dimensional process control Dimensional process control and inspection of passage geometry Dimensional/coating process control • • Insufficient. Excessive vibe stress, etc Excessive. High mechanical stress, etc o o Unbalance tang loading/blade dysfunction Incorrect loading on disk/cracking Width: binding/damping loss, leakage/cavity ingestion Angel wing: cavity ingestion or rotor/stator rubs Poor aero performance Airfoil vibratory mode changes due to thickness distribution Blade throat area – Bearing load, cavity purge, operability, work split, stage loading Weight Airfoil stress/life Small area: large pressure loss, backflow, ingestion, over- temperature Large area: Insufficient blade cooling Blade to blade tip loading Poor tip sealing, excessive leakage, poor performance 40 Part and System Failure Modes • • • • • • • • • • • • • Mechanical/Functional, failure due to vibration from nominal Pre-twist Seal teeth geometry Shape Flatness Tang relative location and taper Tolerance (blade root and disk fir tree dimensional spectrums and blade producibility limitations) Width Angel wing length Aero contour/stagger angle Thickness distribution Twist/lean/bow Passage area and blockage Turbulator height and shape Internal wall coating Variance-fluctuations in measurements Measurement gauge repeatability and reliability Key Characteristics • • • • • • • • • Thickness vs. chord and span • • • Notch shape and thickness • • • • Characteristic Critical to Part Functionality Dovetail or attachment Platform Airfoil external shape Airfoil wall thickness (if cooled) Airfoil internal cavities (if cooled) Cross notch/cross shroud Tolerance AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5 2-6 2-7

8/19/09

Acceptable stresses and frequencies Grain orientation, as required Adequate material properties Operational effects accounted for Relevant properties are used Acceptable blade weight Acceptable stresses Blade “fit” in hot condition Risk Mitigation and Control Material selection Master heat and process control Verify: • • • Verify: • • • • • Verify that grain orientation or low angle boundaries are accounted for Process control and inspection Verify adequate environmental properties Control of chemistry and application process Verify thermal-mechanical compatibility with base material Control of chemistry and application process Poor mechanical or environmental properties Poor coating adherence Excessive blade weight Excessive thermal stresses Interference with surrounding hardware Excessive strain-controlled stress Undesirable natural frequency Low material properties, blade dysfunction Material capability consumed in operation Low material properties, blade dysfunction LCF property reduction due to poor coating selection/requirements, blade cracking Cracking from oxidation/corrosion pitting Insufficient gap, high mechanical stress, etc Excessive gap, excessive vibe stress, etc 41 Part and System Failure Modes • • • • • • • • • • Material property reduction due to excessive grain angle or low angle boundaries, blade dysfunction Cracking from oxidation/corrosion pitting, blade dysfunction • • High blade stress due to improper blade tip gapping. • • Major elements - % Variation Impurities Density Thermal conductivity Coefficient of thermal expansion Refractive index (x-rays) Melting point Modulus (vs. grain orientation) Columnar crystal orientation angles Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF) Long term metallurgical stability Thin wall effects (if cooled) Grain structure (size, shape, flow, boundaries, gamma prime size and volume fraction) Low angle boundaries Directional properties Hardness Melting point Crack propagation rate Refractive index Oxidation, corrosion, erosion, fretting resistance Elevated temperature (creep, diffusion, ageing, temp. gradients) Rubbing, FOD resistance Coverage and thickness Long term stability Oxidation and corrosion resistance Coating material composition and density Coverage and thickness uniformity Coating and diffusion zone microstructure Adhesion Hardness Residual stress Stripping requirements Bonding (interface contamination) Compatibility with base material/other coatings Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Cast structure Environmental resistance Environmental coating Notch coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5 3-6 3-7

8/19/09

Risk Mitigation and Control Process control (mold setup, casting process, and filtration) Process control and sequencing Process control and sequencing Correct sequencing of braze or weld cycles in the process Process control Process control proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Verify part is tolerant to Part and System Failure Modes Crack growth from inclusion or porosity Poor coating adhesion, corrosion and oxidation Incorrect Gamma prime size/spacing leading to low material properties Material property reduction Incorrect dovetail compressive stress, cracking, and blade dysfunction Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, blade dysfunction Inclusions and porosity Internal surface cleanliness Time @ temperature and ramp rates Manufacturing sequence Atmosphere Weld or braze strength Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitates, gamma prime and volume fraction Porosity Diffusion zone (brazing) Heat affected zone (welding) Penetration (welding) Excess braze allowance Filler metal selection Intensity Coverage Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS, RSA, ESA, etc) Key Characteristics • • • • • Effect on base material properties, based on the following: • • • • • • • • • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Characteristic Critical to Part Functionality Casting cleanliness Heat treatment Welding and brazing Shot peen Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.) and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and Significant Process Identification and Substantiation AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/Number 4-1 4-2 4-3 4-4 4-5 4-6 4-7

8/19/09

Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman diagram Use applicable properties Use applicable dA/dN curve Predict K using expected defect size Perform analysis with predicted coating loss Verify part is tolerant to vibration Verify correct inputs to lifing process Verify correct ‘mission mixing’ used Using incorrect properties Failing to address the ‘key characteristics’ Part and System Failure Modes Inadequate part life due to analysis under-predicting part temperature, thermal or mechanical stress Inadequate part life due to analysis over-predicting the blade cooling Inadequate part life due to analysis • • Blade resonant vibration, cracking, dysfunction Blade rupture cracking, dysfunction Crack growth from defect High thermal stress or part temperature, blade dysfunction Inadequate part life due to vibration Inadequate part life due to analysis under-predicting Flow path temperatures, pressures, and velocities Rotor speed Secondary flow circuit Blade cooling flow Blade cooling Temperature effects Multi-axial effects Hold time effects Mean stress effects Notch effects Coating effects Mesh size Temperature effects Vibration and mean stress effects Temperature effects Material thickness effects Temperature effects Threshold stress intensity Crack growth rate Part temperature Thermal stress Blade or engine characteristics Degree of variation required to assure adequate vibratory stress dampening. Predicted stress and Temperature Root loading profile shifts Material Properties Operating during part life Life impact on disk Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Operating conditions Blade cooling (if cooled) LCF life analysis – airfoil and shank HCF life analysis Creep and rupture life analysis Fracture mechanics Tolerance to missing coating Variation Life calculation

AC 33-8 Appendix 2 Section 5 – Analysis Section/Number 5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9

8/19/09 Risk Mitigation and Control Comments ICAs including on-wing inspection requirements and on-wing limits Part and System Failure Modes Could be affected Fatigue Corrosion (hot and cold) Erosion Creep Stress rupture Tensile strength Cooling effectiveness Internal contamination Cleaning requirements Vibration Microstructure Creep Hot corrosion Tensile strength Key Characteristics • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Durability Over-temperature the engine Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4.

AC 33-8 Appendix 2 Section 6 – Testing Section/Number 6-1 6-2 Section 7 – Potential Impact on Regulatory Requirements 8/19/09 Weight and center-of-gravity affect on rotor forces and LCF capability Durability; weight and failure modes relative to containment capability Weight affect on rotor forces during over-speed Blade vibration-Design Turbine effective area-Operating line migration, Blade-Rub strip interaction Turbine efficiency/performance Turbine blade release-Case containment Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected supercharger rotors Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction: Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

AC 33-8 Appendix 2 8/19/09 Blade vibration Blade durability Blade over temperature capability Blade in-service inspection limits Failure of the most critical turbine blade while operating at maximum permissible r.p.m.

Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) (Weight changes) mode Subpart E – Design and Construction: Turbine Aircraft Engines 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2 8/19/09 (all features may not be applicable) Template #5: Turbine Vane Cooled Nomenclature for Generic Component Features AC 33-8 Appendix 2

8/19/09

Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Risk Mitigation and Control Surface dimensional process control • • Verify capability exceeds expected utilization Low vane cooling flow: vane over-temperature/dysfunction High vane cooling flow, and/or low purge cavity delivery flow; reduced rotor cavity purge/ingestion/part dysfunction Poor distribution of cooling air: over-temperature, and existing bench flow limits not valid Vane resonant vibration, cracking, dysfunction Static structure malfunction Crack growth from LCF or creep – rupture Part and System Failure Modes Engine mass and CG • • • • • • As-cast surfaces Machined surfaces Total flow rate Individual circuit-cavity flow rate Flow distribution Static pressure distribution Discharge pressure at showerhead, relative to turbine gas flow pressure Distribution of post and pre impingement air to the rotor cavities Vane natural frequencies Major load path Vane geometry Vane cooling Material mechanical/metallurgical/physical properties Vane cleaning requirements/effectiveness (internal passages-intergranular attack) Key Characteristics • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Weight Cooling air utilization Structural strength and vibration characteristics Creep, LCF, fracture toughness, tensile overload capability AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4

8/19/09

Verify part is tolerant to variation Control of manufacturing and inspection processes Verify part is tolerant to variation Control of manufacturing and inspection processes Verify part is tolerant to variation Control of manufacturing and inspection processes Dimensional process control.

Risk Mitigation and Control Dimensional process control and inspection Surface dimensional process control Assessment of exit flow characteristics Dimensional process control Dimensional process control and inspection of passage geometry • • • • • • • Unbalance: tang loading/dysfunction Width: binding, leakage/cavity ingestion Poor aero performance Airfoil vibratory mode changes due to thickness distribution Vane throat area – bearing load, cavity purge, operability, work split, stage loading Weight Airfoil stress/life Small area: large pressure loss, backflow, ingestion, over- temperature Large area: insufficient vane cooling Low flow: excessive pressure loss, back flow, etc High flow: low impingement cooling, excessive part temp, etc Low standoff: low impingement cooling, excessive part temp, etc Insufficient interstage sealing: Insufficient upstream cavity purge, etc Excessive interstage sealing: Insufficient downstream cavity purge, etc Poor cutting characteristics, rubbing, thermal instability, etc Failure due to stress concentration. 49 Part and System Failure Modes • • • • • • • • • Mechanical/Functional, failure due to vibration from nominal • • • • • • • Arc length Axial location of forward and aft face Functional fits at interfaces Part/assembly locating features (axial, radial and tangential) Inner and outer gas path contours Air sealing surfaces (axial, radial and tangential) Surface finish Aero contour/stagger angle Thickness distribution Effects on down stream turbine blades Passage area and blockage Turbulator height and shape Internal wall coating Variance-fluctuations in measurements Measurement gauge repeatability and reliability Mass flow Standoff Dimension Honeycomb dimensions Filet profile Key Characteristics • • • • • • • • • • Thickness vs. chord and span • • • • • • • • • • Characteristic Critical to Part Functionality Inner and outer platforms Airfoil external shape Airfoil wall thickness Airfoil internal cavities Tolerance Cooling baffle Interstage seal Airfoil to platform filets AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8

8/19/09

Acceptable stresses and frequencies Grain orientation, as required Adequate material properties Operational effects accounted for Relevant properties are used Acceptable vane weight Acceptable stresses Vane “fit” in hot condition Control of chemistry and application process Verify thermal-mechanical compatibility with base material Risk Mitigation and Control Material selection Master heat and Process control Verify: • • • Verify: • • • • • Verify that grain orientation or high angle boundaries are accounted for Process control and inspection Verify adequate environmental properties • • Poor mechanical or environmental properties Poor TBC adherence Excessive vane weight Excessive thermal stresses Interference with surrounding hardware Excessive strain-controlled stress Undesirable natural frequency Low material properties, vane dysfunction Material capability consumed in operation LCF property reduction due to poor coating selection/requirements, vane cracking Cracking from oxidation/corrosion pitting Part and System Failure Modes • • • • • • • • • Material property reduction due to excessive grain angle or high angle boundaries (HAB), Cracking from oxidation/corrosion pitting, vane dysfunction • • Major elements - % variation Impurities Density Coefficient of thermal expansion Refractive index (x-rays) Modulus (vs. grain orientation) Columnar crystal orientation angles Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF) Long term metallurgical stability Thin wall effects Grain structure (size, shape, flow, boundaries, gamma prime size and volume fraction, recrystallization) Inclusions Freckling Porosity High angle boundaries - directional properties Hardness Melting point Crack propagation rate Refractive index Oxidation, corrosion, erosion, fretting resistance Elevated temperature (creep, diffusion, ageing, temp. gradients) FOD resistance Coverage and thickness Long term stability Oxidation and corrosion resistance Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Cast structure Environmental resistance Environmental coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5 3-6

8/19/09

Process control (mold setup, casting process, and filtration) Process control and sequencing Correct sequencing of braze or weld cycles in the process Process control Risk Mitigation and Control • • Process control and sequencing • • Process control Control of chemistry and application process Verify part is tolerant to missing TBC No high TBC temperatures that accelerate spalling, or molten dirt infiltration Risk Mitigation and Control • • • Part and System Failure Modes Crack growth from inclusion or porosity Poor coating adhesion, corrosion and oxidation Incorrect Gamma prime size/spacing leading to low material properties Material property reduction Incorrect compressive stress, cracking, and vane dysfunction Part and System Failure Modes High thermal stresses or part temperature, vane dysfunction Inclusions and porosity Internal surface cleanliness Time @ temperature and ramp rates Manufacturing sequence Atmosphere Weld or braze strength Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitates, gamma prime and volume fraction Porosity Diffusion zone (brazing) Heat affected zone (welding) Penetration (welding) Excess braze allowance Filler metal selection Intensity Coverage Key Characteristics • • • • • Effect on base material properties, based on the following: • • • • • • • • • • Coating material composition and density Thermal conductivity (coefficient of thermal expansion) Coverage and thickness uniformity Coating and diffusion zone microstructure Adhesion Oxidation Resistance to spalling, sintering and erosion Hardness Residual Stress Stripping requirements Bonding (interface contamination) Compatibility with base material/other coatings Key Characteristics • • • • • • • • • • • • Characteristic Critical to Part Functionality Casting cleanliness Heat treatment Welding and brazing Shot peen Characteristic Critical to Part Functionality Thermal barrier coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-7 Section 4 – Part Materials and Processes - Processing Section/Number 4-1 4-2 4-3 4-4

8/19/09

Verify part is tolerant to proposed limits Process control Risk Mitigation and Control • • Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Use applicable dA/dN curve Predict K using expected defect size Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman Diagram Use applicable properties • • Perform analysis with predicted TBC loss Using incorrect properties Failing to address the ‘key characteristics’ Part and System Failure Modes Compressor operability Inadequate part life due to analysis over- predicting the vane cooling Inadequate part life due to analysis • • Vane resonant vibration, cracking, dysfunction Vane rupture cracking, dysfunction Crack growth from defect High thermal stress or part temperature, vane dysfunction Part and System Failure Modes Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, vane dysfunction Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS, RSA, ESA, etc) Key Characteristics Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Flow path temperatures, pressures, and velocities Nozzle Area Secondary flow circuit Vane cooling flow Vane cooling Temperature effects Multi-axial effects Hold time effects Mean stress effects Notch effects Coating effects Mesh size Temperature effects Vibration and mean stress effects Temperature effects Material thickness effects Temperature effects Threshold stress intensity Crack growth rate Part temperature Thermal stress Key Characteristics • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.) and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Characteristic Critical to Part Functionality Operating conditions Vane cooling LCF/TMF life analysis – airfoil and shrouds HCF life analysis Creep and rupture life analysis Fracture mechanics Tolerance to missing TBC AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/Number 4-5 4-6 4-7 Section 5 – Analysis Section/Number 5-1 5-2 5-3 5-4 5-5 5-6 5-7

8/19/09

Risk Mitigation and Control Risk Mitigation and Control Verify part is tolerant to vibration Verify correct inputs to lifing process Verify correct ‘mission mixing’ used Part and System Failure Modes Inadequate part life due to vibration Inadequate part life due to analysis under- predicting Part and System Failure Modes Nozzle or engine characteristics Predicted stress and temperature Material properties Operating during part life Fatigue Corrosion (hot and cold) Erosion Creep Stress rupture Tensile strength Cooling effectiveness Internal contamination Cleaning requirements Microstructure Creep Hot corrosion Tensile strength Key Characteristics • • • • Key Characteristics • • • • • • • • • • • • • Characteristic Critical to Part Functionality Variation Life calculation Characteristic Critical to Part Functionality Durability Over-temperature AC 33-8 Appendix 2 Section 5 – Analysis Section/Number 5-8 5-9 Section 6 – Testing Section/Number 6-1 6-2

8/19/09

Comments ICAs including on-wing inspection requirements and on-wing limits Turbine cooling Could be affected Could be affected Could be affected Could be affected Could be affected General – the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Turbine cooling Vane vibration Turbine effective area-Operating line migration Turbine efficiency/performance Turbine vane release – downstream effects Vibration Vane durability Vane over temperature capability Blade in-service inspection limits Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36.

AC 33-8 Appendix 2

8/19/09

Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Outer Shroud or Ring

Vane Packets (may be segmented or continuous)

(all features may not be applicable)

Template #6: Turbine Vane Uncooled

Nomenclature for Generic Component Features

Vane Airfoil

Inner Shroud, Ring or Platform

AC 33-8 Appendix 2

8/19/09

Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Risk Mitigation and Control Surface dimensional process control • • Verify capability exceeds expected utilization Risk Mitigation and Control Dimensional process control and inspection Dimensional process control Surface dimensional process control Vane resonant vibration, cracking, dysfunction Static structure malfunction Poor aero performance Airfoil vibratory mode changes due to thickness distribution Effect on downstream turbine blade vibratory response Vane throat area – bearing load, cavity purge, operability, work split, stage loading Weight Part and System Failure Modes Engine mass and CG • • Crack growth from LCF or creep – rupture Part and System Failure Modes Unbalance tang loading/blade dysfunction Width: binding, leakage/cavity ingestion • • • • • As-cast surfaces Machined surfaces Vane natural frequencies Major load path Vane geometry Vane cooling Material mechanical/metallurgical/physical properties Vane cleaning requirements/effectiveness (internal passages-intergranular attack) Key Characteristics • • • • • • • • Arc length Axial location of forward and aft face Functional fits at interfaces Part/assembly locating features (axial, radial and tangential) Inner and outer airsealing surfaces (axial, radial and tangential) Inner and outer gas path contours Sealing surfaces, surface finish Width Aero contour/stagger angle Thickness distribution Key Characteristics • • • • • • • • • • Characteristic Critical to Part Functionality Weight Structural strength and vibration characteristics Creep, LCF, fracture toughness, tensile overload capability Characteristic Critical to Part Functionality Inner and outer shroud or platform Platform Airfoil external shape AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3

8/19/09

Verify part is tolerant to variation Control of manufacturing and inspection processes Verify part is tolerant to variation Control of manufacturing and inspection processes Dimensional process control • • • • • Acceptable stresses and frequencies Grain orientation, as required Adequate material properties Operational effects accounted for Relevant properties are used Verify that grain orientation or high angle boundaries are accounted for Process control and inspection Acceptable vane weight Acceptable stresses Vane “fit” in hot condition Risk Mitigation and Control Material selection Master heat and process control Verify: • • • Verify: • • • • • • • Insufficient interstage sealing: Insufficient upstream cavity purge, etc. Excessive interstage sealing: Insufficient downstream cavity purge, etc. Poor cutting characteristics, rubbing, thermal instability, etc Mechanical/functional, failure due to vibration from nominal • • • Failure due to stress concentration Poor mechanical or environmental properties Poor TBC adherence Excessive Vane Weight Excessive thermal stresses Interference with surrounding hardware Excessive strain-controlled stress Undesirable natural frequency Low material properties, vane dysfunction Material capability consumed in operation Part and System Failure Modes • • • • • • • • • Material property reduction due to excessive grain angle or high angle boundaries (HAB), Variance-fluctuations in measurements Measurement gauge repeatability and reliability Dimension Honeycomb dimensions Filet profile Major elements - % variation Impurities Density Coefficient of thermal expansion Refractive Index (x-rays) Modulus (vs. grain orientation) Columnar crystal orientation angles Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF) Long term metallurgical stability Grain structure (size, shape, flow, boundaries, gamma prime size and volume fraction, recrystallization) Inclusions Freckling Porosity High angle boundaries directional properties Hardness Melting point Crack propagation rate Refractive index • • • • • Key Characteristics • • • • • • • • • • • • • • • • • • Tolerance Interstage seal Airfoil to platform filets Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Cast structure AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system 2-4 2-5 2-6 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4

8/19/09

Process control (mold setup, casting process, and filtration) Process control and sequencing Risk Mitigation and Control • • Process control and sequencing Verify adequate environmental properties Verify thermal-mechanical compatibility with base material No high TBC temperatures that accelerate spalling, or molten dirt infiltration Control of chemistry and application process Control of chemistry and application process Verify part is tolerant to missing TBC Risk Mitigation and Control • • • • • • Part and System Failure Modes Crack growth from inclusion or porosity Poor coating adhesion, corrosion and oxidation Incorrect Gamma prime size/spacing leading to low material properties LCF property reduction due to poor coating selection/requirements, vane cracking Cracking from oxidation/corrosion pitting Part and System Failure Modes Cracking from oxidation/corrosion pitting, vane dysfunction • • High thermal stresses or part temperature, vane dysfunction Inclusions and porosity Internal surface cleanliness Time @ temperature and ramp rates Manufacturing sequence Atmosphere Key Characteristics • • • • • Oxidation, corrosion, erosion, fretting resistance Elevated temperature (creep, diffusion, ageing, temp. gradients) FOD resistance Coverage and thickness Long term stability Oxidation and corrosion resistance Coating material composition and density Thermal conductivity (coefficient of thermal expansion) Coverage and thickness uniformity Coating and diffusion zone microstructure Adhesion Oxidation Resistance to spalling, sintering and erosion Hardness Residual stress Stripping requirements Bonding (interface contamination) Compatibility with base material/other coatings Key Characteristics • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Casting cleanliness Heat treatment Characteristic Critical to Part Functionality Environmental resistance Environmental coating Thermal barrier coating (if used) AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-5 3-6 3-7 Section 4 – Part Materials and Processes - Processing Section/Number 4-1 4-2

8/19/09

Risk Mitigation and Control Correct sequencing of braze or weld cycles in the process Process control Process control proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Verify part is tolerant to Part and System Failure Modes Material property reduction Incorrect compressive stress, cracking, and vane dysfunction Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, vane dysfunction Weld or braze strength Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitates, gamma prime and volume fraction Porosity Diffusion zone (brazing) Heat affected zone (welding) Penetration (welding) Excess braze allowance Filler metal selection Intensity Coverage Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS, RSA, ESA, etc) Key Characteristics Effect on base material properties, based on the following: • • • • • • • • • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Characteristic Critical to Part Functionality Welding and brazing Shot peen Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.) and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/Number 4-3 4-4 4-5 4-6 4-7

8/19/09

Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman Diagram Use applicable properties Use applicable dA/dN curve Predict K using expected defect size Perform analysis with predicted TBC loss Verify part is tolerant to vibration Verify correct inputs to lifing process Verify correct ‘mission mixing’ used Using incorrect properties Failing to address the ‘key characteristics’ Part and System Failure Modes Compressor operability Inadequate part life due to analysis • • Vane resonant vibration, cracking, dysfunction Vane rupture cracking, dysfunction Crack growth from defect High thermal stress or part temperature, vane dysfunction Inadequate part life due to vibration Inadequate part life due to analysis under-predicting Flow path temperatures, pressures, and velocities Nozzle area Temperature effects Multi-axial effects Hold time effects Mean stress effects Notch effects Coating effects Mesh size Temperature effects Vibration and mean stress effects Temperature effects Material thickness effects Temperature effects Threshold stress intensity Crack growth rate Part temperature Thermal stress Nozzle or engine characteristics Predicted stress and temperature Material properties Operating during part life Key Characteristics • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Operating conditions LCF/TMF life analysis – airfoil and shrouds HCF life analysis Creep and rupture life analysis Fracture mechanics Tolerance to missing TBC Variation Life calculation

AC 33-8 Appendix 2 Section 5 – Analysis Section/Number 5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8

8/19/09

Risk Mitigation and Control Comments ICAs including on-wing inspection requirements and on-wing limits Part and System Failure Modes Could be affected Fatigue Corrosion (hot and cold) Erosion Creep Stress rupture Tensile strength Internal contamination Cleaning requirements Microstructure Creep Hot corrosion Tensile strength Key Characteristics • • • • • • • • • • • • the engine Characteristic Critical to Part Functionality Durability Over-temperature Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4.

AC 33-8 Appendix 2 Section 6 – Testing Section/ Number 6-1 6-2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Vane vibration Turbine effective area-Operating line migration Turbine efficiency/performance Turbine vane release Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected supercharger rotors Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction: Turbine Aircraft Engines 33.62 Stress Analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

AC 33-8 Appendix 2

8/19/09

Vibration Vane durability Vane over temperature capability Blade in-service inspection limits Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) (Weight changes) mode Subpart E – Design and Construction: Turbine Aircraft Engines 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B- Certification Standard Atmospheric Concentrations of Rain and Hail 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Threaded Feature

Balance Areas Material

Spline

Shoulder Feature

Wall Thickness

(all features may not be applicable)

Template #7: Shaft – Not Life-limited

Active Surface

Nomenclature for Generic Component Features

Run Out

AC 33-8 Appendix 2

8/19/09

Surface dimensional process control Dimensional control Machining process control Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Verify capability exceeds expected duty cycle Surface dimensional process control Verify acceptable wear couple Dimensional process control and inspection Dimensional process control • • • • • • • • • • Risk Mitigation and Control Risk Mitigation and Control Inertia Correct length Heat dissipation Vibration response Shaft resonant vibration, cracking Shaft separation from overload Crack growth from LCF, HCF, or HCF/LCF interaction Surface fret Bearing spinning Dimensional checks Part and System Failure Modes • • • • • • • • • •

Vibration Resonant frequencies Scuffing Parts mislocated with in engine 67

Part and System Failure Modes • • • • As-forged surfaces Machined surfaces Diameters Attachment point form Surface finish Surface hardness Shaft natural frequencies Vibration stress distribution Cycles to failure demonstration Shaft geometry Material mechanical/metallurgical/physical properties Surface finish Press fit Retaining thread Wear resistance on mating component Splines Key Characteristics • • • • • • • • • • • • • • • • Shape Surface finish Internal/external diameter Edge break, relief cuts Splines Threads Integral raceways Oil holes Distance to features from datum Key Characteristics • • • • • • • • • Characteristic Critical to Part Functionality Weight Shaft geometry Vibration characteristics (HCF capability) LCF, fracture toughness, tensile overload capability Attachment features Characteristic Critical to Part Functionality Shaft features Feature locations AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2

8/19/09

Surface dimensional process control Verify part is tolerant to variation Control of manufacturing and inspection processes • • • Risk Mitigation and Control Acceptable stresses and frequencies Forging grain flow as required Adequate material properties Operational effects accounted for Impact testing Acceptable stresses Operating conditions Risk Mitigation and Control Material selection Process control Verify: • • Verify: • • • • • Verify that variations in grain structure are accounted for Process control & inspection Verify adequate environmental properties Gear vibratory mode changes due to thickness distribution Weight – excessive inertia load Stress/life Mechanical/functional, failure due to variation from nominal Excessive weight Excessive loading on retaining features Undesirable natural frequencies Low material properties: shaft yield or break Spalling during operation Material property reduction due to abnormal grain structure, vibration, Spalling from oxidation/corrosion pitting Property reduction due to extreme oil overtemperature or lack of cooling oil 68 Part and System Failure Modes • • • • Part and System Failure Modes Poor mechanical or environmental properties • • • • • • • Transition areas Thickness distribution Attaching features Dampening features Balancing features Variance-fluctuations in measurements Measurement gauge repeatability and reliability Major elements - % variation Impurities Density Coefficient of thermal expansion Melting point Modulus Forging grain flow angles Tensile, UTS, YS, elongation, stress rupture, creep, LCF, HCF Endurance limit Fracture mechanics Plasticity model Sudden overload properties Surface hardness Grain structure (size, shape, flow, boundaries) Directional properties Hardness Forging laps Homogeneity of forging work throughout part Oxidation, corrosion, fretting resistance Elevated temperature stress relaxation Surface coating Key Characteristics • • • • • • • Key Characteristics • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Wall thickness Tolerance Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Forged structure Environmental resistance AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-3 2-4 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5

8/19/09

Risk Mitigation and Control Process control (melt control, cleanliness Process control and sequencing Process control and sequencing Correct sequencing of weld process Process control Process control Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Process control and sequencing Process control and sequencing structure processing Incorrect compressive stress, cracking Improper case depth Hardness improper Cracking from excessive defect size Inadequate final part form, or defect “escape” Material property reduction due to abnormal grain Material property reduction due to improper Crack growth from inclusion or porosity Inadequate material properties Incorrect structure leading to low material properties Material property reduction Weld failure Part and System Failure Modes • • • • • • • • • • • • Inclusions and porosity Micro structural characteristics Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Weld strength Microstructure: grain size, shape, flow, defects, grain boundary precipitates Porosity Heat affected zone Filler metal selection Joint design Intensity Coverage Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Grain Structure (size, shape, flow, boundaries) Directional properties Hardness Forging laps Homogeneity of forging work throughout part Carburizing Shot peening Coating Polishing Key Characteristics • • • • • • Effect on base material properties, based on the following: • • • • • • • • • • • • • • • • • Forging structure • • • • • Effect on base material properties, based on the following: • • • • Characteristic Critical to Part Functionality Raw material processing Heat treatment Welding Peening Surface hardening Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Forging process Surface treatments AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3 4-4 4-5 4-7 4-8 4-9 4-10

8/19/09

Perform adequate component and/or engine testing Engine testing Process control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman Diagram Use applicable dA/dN curve Predict K using expected defect size Verify part is tolerant to variation Verify correct inputs to lifing process Risk Mitigation and Control • • • • • • • • • • • Risk Mitigation and Control temperature, mechanical stress Shaft separation Excessive vibration Engine manual build sheets Inadequate part life due to analysis under-predicting part Inadequate part life due to analysis Using incorrect properties Failing to address the ‘key characteristics’ Shaft resonant vibration, cracking, whipping Critical frequency, bending modes Crack growth from defect Inadequate part life due to variation Inadequate part life due to analysis under-predicting • • • Part and System Failure Modes Part and System Failure Modes • • • • • • • • • Torque loads Oil temperatures Speeds Transient loads Temperature effects Overloads Temperature effects Vibration and mean stress effects Temperature effects Threshold stress intensity Damage tolerance Engine operation characteristics Predicted stress and temperature Material properties Operation during part life Key Characteristics • • • • • • • • • • • • • • • Fatigue Tensile strength Spalling Engine vibration response Microstructure Vibration signature Build tolerances Key Characteristics • • • • • • • Characteristic Critical to Part Functionality Operating conditions LCF life assessment HCF life analysis Fracture mechanics Variation Life calculation Characteristic Critical to Part Functionality Durability Operability and performance Locating features AC 33-8 Appendix 2 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 5-4 5-5 5-6 Section 6 – Testing Section/ Number 6-1 6-2 6-3

8/19/09

Comments ICAs including on-wing inspection requirements and on-wing limits Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Shaft stress analysis Shaft vibration Continued integrity Shaft release Sudden shaft loading Sudden shaft loading Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.

AC 33-8 Appendix 2

8/19/09

Shaft vibration-Demonstration test Shaft durability Could be affected Could be affected Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 -Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Outer Race

Inner Race

Roller Crowning Roller Element

Inner Diameter

Outer Diameter

(all features may not be applicable)

Template #8: Roller Bearing

Nomenclature for Generic Component Features

Separator

Active Surface

Active Surface

Radius Typical

Lead-in Chamfer

AC 33-8 Appendix 2

8/19/09

Dimensional process control Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Verify capability exceeds expected duty cycle Surface dimensional process control Verify acceptable wear Surface dimensional process control • • • • • • • Risk Mitigation and Control Spalling, metal contamination Bearing resonant vibration, cracking, spalling Bearing separation from overload Crack growth from LCF, HCF, or HCF/LCF interaction Surface fret Metal contamination Bearing spinning Excessive race loading Spalling • • • • • • • • • Part and System Failure Modes Design load Bearing natural frequencies Vibration stress distribution Cycles to failure demonstration Vibration test Roller, raceway, separator design Material mechanical/metallurgical/physical properties Surface finish Design speed Cooling requirements Press fit Retaining features Wear resistance on mating component Roller loading Roller diameter Separator design Key Characteristics • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Radial loading Vibration characteristics (HCF capability) Fatigue life Lubrication requirements Design speed AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5

8/19/09

Dimensional process control and inspection Dimensional process control Surface dimensional process control Dimensional process control Dimensional process control and inspection Dimensional process control and inspection Verify part is tolerant to variation Control of manufacturing and inspection processes • • • • • • • • Risk Mitigation and Control Installation into engine Vibration Vibratory mode changes Bearing installation Spinning Vibration mode changes Oil retention Vibration mode changes End loading Scuffing Spalling Noisy Mechanical/functional, failure due to variation from nominal

• • • • • • • • • • • • • 76

Part and System Failure Modes Inside diameter Outside diameter Oil hole size, location Edge break Inner/outer runout Inner/outer corner radii Thickness distribution Edge breaks Dampening features Actual measurements of finish for all components of the bearing Radial play Axial play Face protrusion Raceway radial roundness Raceway waviness Raceway curvature Raceway shoulder height Raceway straightness Bearing-to-cage face clearance Diametral cage land clearance Roller grade Ring wall thickness Roller profile control parameters Internal radial clearance (IRC) Variance-fluctuations in measurements Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Boundary dimensions Geometric dimensions Anti-rotation features Surface finish Fit-up dimensions Internal geometry Tolerance AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5 2-6 2-7

8/19/09

Process control (melt control, cleanliness) Process control and sequencing Process control and sequencing Process control Process control • • • • • Risk Mitigation and Control Material selection Process control Acceptable weight Acceptable stresses Hot/cold oil distress Acceptable stresses and frequencies Forging grain flow as required Adequate material properties Operational effects accounted for Impact testing Process Control Verify adequate environmental properties Risk Mitigation and Control • • • • • • • • • • • • Crack growth from inclusion or porosity Inadequate material properties Incorrect structure leading to low material properties Improper thickness and coverage Incorrect compressive stress, cracking Part and System Failure Modes • • • • • Poor mechanical or environmental properties Excessive weight Excessive loading on retaining features Undesirable natural frequencies Low material properties Spalling during operation Spalling Vibration Excess heat Spalling from oxidation/corrosion pitting Property reduction due to extreme oil overtemp or lack of cooling oil 77 Part and System Failure Modes • • • • • • • • • • • Inclusions and porosity Micro structural characteristics Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Plating Intensity Coverage Key Characteristics • • • • • • • • • Major elements - % variation Impurities Density Coefficient of thermal expansion Melting point Modulus Forging grain flow angles Tensile, UTS, YS, elongation, stress rupture, creep, LCF, HCF Sudden overload properties Surface hardness depth Surface hardness Roller nominal diameter Roller cylindricity Roller length Roller crown drop Roller corner Radius Oxidation, corrosion, fretting resistance Elevated temperature stress relaxation Surface plating Key Characteristics • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Roller Environmental resistance Characteristic Critical to Part Functionality Raw material processing Heat treatment Surface treatment Peening AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3 4-4

8/19/09

Process control Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters • • • • • Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman diagram Use applicable dA/dN curve Predict K using expected defect size Verify part is tolerant to variation Verify correct inputs to lifing process • • • • • • • • Risk Mitigation and Control Improper case depth Hardness improper Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape” Part and System Failure Modes • • • • • Inadequate part life due to analysis under-predicting part temperature, mechanical stress Inadequate part life due to analysis Using incorrect properties Failing to address the ‘key characteristics’ Resonant vibration, cracking Crack growth from defect Inadequate part life due to variation Inadequate part life due to analysis under-predicting • • • • • • • • Part and System Failure Modes Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack • • • • • Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Key Characteristics • • • • Micro cracks or recast: Fatigue capability degradation, due to: • • • • • Torque loads Oil temperatures Speeds Transient loads Axial/radial loads Temperature effects Overloads FOD impact Temperature effects Vibration and mean stress effects Temperature effects Threshold stress intensity Engine operation characteristics Predicted stress and temperature Material properties Operation during part life Key Characteristics • • • • • • • • • • • • • • • •

Analysis

–

Characteristic Critical to Part Functionality Surface hardening Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.)and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Characteristic Critical to Part Functionality Operating conditions LCF life assessment HCF life analysis Fracture mechanics Variation Life calculation AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/ Number 4-5 4-6 4-7 4-8 Section 5 Section/ Number 5-1 5-2 5-3 5-4 5-5 5-6

8/19/09

Perform adequate component and/or engine testing Engine testing • • Risk Mitigation and Control Comments ICAs including on-wing inspection requirements and on-wing limits for oil analysis Bearing surface breakdown Excessive vibration Metal particles in oil Excessive oil temperature 79 • • • • Part and System Failure Modes Could be affected Fatigue Tensile strength Spalling Engine vibration response Microstructure Vibration signature Abnormal wear Maximum pad loading Key Characteristics • • • • • • • • the engine

Testing

–

Characteristic Critical to Part Functionality Durability Operability and performance Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4.

AC 33-8 Appendix 2 Section 6 Section/ Number 6-1 6-2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Bearing vibration-Design Continued integrity Bearing/Gear/Shaft release Could be affected Could be affected Could be affected Could be affected Could be affected supercharger rotors Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

AC 33-8 Appendix 2

8/19/09

Sudden bearing radial loading Sudden bearing radial loading Bearing vibration Bearing durability Bearing in-service inspection limits Bearing wear must be within serviceable limits Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) (Weight changes) mode Subpart E – Design and Construction; Turbine Aircraft Engines 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Ball

Inner Raceway

Separator

Outer Raceway

r

Inner Diameter

Template #9: Ball Bearing (all features may not be applicable)

Dimension

Cross-Corner

Outer Diamete

Nomenclature for Generic Component Features

Retainer Groove

Corner Radius

Puller Groove

AC 33-8 Appendix 2

8/19/09

Dimensional process control Dimensional control Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Verify capability exceeds expected duty cycle Surface dimensional process control Verify acceptable wear Surface dimensional process control • • • • • • • • Risk Mitigation and Control Spalling, metal contamination Spalling, metal contamination Bearing resonant vibration, cracking, spalling Bearing separation from overload Crack growth from LCF, HCF, or HCF/LCF interaction Surface fret Metal contamination Bearing spinning Excessive race loading Spalling • • • • • • • • • • Part and System Failure Modes Design load Design load Bearing natural frequencies Vibration stress distribution Cycles to failure demonstration Vibration test Ball, raceway, separator design Material mechanical/metallurgical/physical properties Surface finish Design speed Cooling requirements Press fit Retaining features Wear resistance on mating component Ball loading Ball diameter Separator design Key Characteristics • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Radial loading Axial loading Vibration characteristics (HCF capability) Fatigue life Lubrication requirements Design speed AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5 1-6

8/19/09

Dimensional process control and inspection Dimensional process control Surface dimensional process control Dimensional process control Dimensional process control and inspection Dimensional process control and inspection Verify part is tolerant to variation Control of manufacturing and inspection processes • • • • • • • • Risk Mitigation and Control Installation into engine Vibration Vibratory mode changes Bearing installation Spinning Vibration mode changes Oil retention Vibration mode changes End loading Scuffing Spalling Noisy Mechanical/Functional, failure due to variation from nominal

• • • • • • • • • • • • • 84

Part and System Failure Modes Inside diameter Outside diameter Oil hole size, location Edge break Inner/outer runout Inner/outer corner radii Thickness distribution Edge breaks Dampening features Actual measurements of finish for all components of the bearing Radial play Axial play Contact angle Face protrusion Raceway radial roundness Raceway waviness Raceway curvature Raceway shoulder height Bearing-to-cage face clearance Diametral cage land clearance Ball grade Ring wall thickness Internal radial clearance Variance-fluctuations in measurements Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Boundary dimensions Geometric dimensions Anti-rotation features Surface finish Fit-up dimensions Internal geometry Tolerance AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5 2-6 2-7

8/19/09

Process control (melt control, cleanliness Process control and sequencing Process control and sequencing Process control Process control Process control • • • • • • Risk Mitigation and Control Material selection Process control Acceptable weight Acceptable stresses Hot/cold oil distress Acceptable stresses and frequencies Forging grain flow as required Adequate material properties Operational effects accounted for Impact testing Verify adequate environmental properties Risk Mitigation and Control • • • • • • • • • • • Crack growth from inclusion or porosity Inadequate material properties Incorrect structure leading to low material properties Improper thickness and coverage Incorrect compressive stress, cracking Improper case depth Hardness improper Part and System Failure Modes • • • • • • • Poor mechanical or environmental properties Excessive weight Excessive loading on retaining features Undesirable natural frequencies Low material properties Spalling during operation Spalling from oxidation/corrosion pitting Property reduction due to extreme oil overtemp or lack of cooling oil 85 Part and System Failure Modes • • • • • • • • Inclusions and porosity Micro structural characteristics Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Plating Intensity Coverage Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Key Characteristics • • • • • • • • • • • • • Major elements - % Variation Impurities Density Coefficient of thermal expansion Melting point Modulus Forging grain flow angles Tensile, UTS, YS, elongation, stress rupture, creep, LCF, HCF Sudden overload properties Surface hardness depth Surface hardness Oxidation, corrosion, fretting resistance Elevated temperature stress relaxation Surface plating Key Characteristics • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Environmental resistance Characteristic Critical to Part Functionality Raw material processing Heat treatment Surface treatment Peening Surface hardening AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3 4-4 4-5

8/19/09

Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters • • • • Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman diagram Use applicable dA/dN curve Predict K using expected defect size Verify part is tolerant to variation Verify correct inputs to lifing process • • • • • • • • Risk Mitigation and Control Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape” Part and System Failure Modes • • • Inadequate part life due to analysis under-predicting part temperature, mechanical stress Inadequate part life due to analysis Using incorrect properties Failing to address the ‘key characteristics’ Resonant vibration, cracking Crack growth from defect Inadequate part life due to variation Inadequate part life due to analysis under-predicting • • • • • • • • Part and System Failure Modes Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack • • • • • Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Key Characteristics Micro cracks or recast: Fatigue capability degradation, due to: • • • • • Torque loads Oil temperatures Speeds Transient loads Axial/radial loads Temperature effects Overloads FOD impact Temperature effects Vibration and mean stress effects Temperature effects Threshold stress intensity Engine operation characteristics Predicted stress and temperature Material properties Operation during part life Key Characteristics • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.)and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Characteristic Critical to Part Functionality Operating conditions LCF life assessment HCF life analysis Fracture mechanics Variation Life calculation AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/ Number 4-6 4-7 4-8 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 5-4 5-5 5-6

8/19/09

Perform adequate component and/or engine testing Engine testing • • Risk Mitigation and Control Comments ICAs including on-wing inspection requirements and on-wing limits for oil analysis Bearing surface breakdown Excessive vibration Metal particles in oil Excessive oil temperature 87 • • • • Part and System Failure Modes Could be affected Fatigue Tensile strength Spalling Engine vibration response Microstructure Vibration signature Abnormal wear Maximum pad loading Key Characteristics • • • • • • • • the engine Characteristic Critical to Part Functionality Durability Operability and performance Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4.

AC 33-8 Appendix 2 Section 6 – Testing Section/ Number 6-1 6-2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Bearing vibration-Design Continued integrity Bearing/Gear/Shaft release Could be affected Could be affected Could be affected Could be affected Could be affected supercharger rotors Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

AC 33-8 Appendix 2

8/19/09

Sudden bearing axial/radial loading Sudden bearing axial/radial loading Bearing vibration Bearing durability Bearing in-service inspection limits Bearing wear must be within serviceable limits Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) (Weight changes) mode Subpart E – Design and Construction; Turbine Aircraft Engines 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Web

Hub

Gear Teeth

Template #10: Gear

(all features may not be applicable)

Rim

Lightening Holes

Nomenclature for Generic Component Features

Bearing Mount

Bearing Stop

Threaded Retention Feature

AC 33-8 Appendix 2

8/19/09

Surface dimensional process control Dimensional control Machining process control Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Verify capability exceeds expected duty cycle for highest load application Surface dimensional process control Verify acceptable wear Surface dimensional process control • • • • • • • • • Risk Mitigation and Control Bearing loading Inertia Correct speed Heat generation Metal generation Gear resonant vibration, cracking Tooth separation from overload Crack growth from LCF, HCF, or HCF/LCF interaction Surface fret Metal contamination Bearing spinning Excessive tip cracking or corner loss • • • • • • • • • • • • Part and System Failure Modes As-forged surfaces Machined surfaces Number of teeth Gear tooth form Surface finish Surface hardness Gear natural frequencies Vibration stress distribution Cycles to failure demonstration Vibration test Tooth/web geometry Material mechanical/metallurgical/physical properties Surface finish Press fit Retaining thread Wear resistance on mating component Hole size and location Distance from hub and rim Surface finish Key Characteristics • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Weight Gear tooth geometry Vibration characteristics (HCF capability) LCF, fracture toughness, tensile overload capability Bearing attachment Weight reduction AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5 1-6

8/19/09

Dimensional process control and inspection Dimensional process control Surface dimensional process control Dimensional process control Verify part is tolerant to variation Control of manufacturing and inspection processes • • • • • • Risk Mitigation and Control Material selection Process control Acceptable gear weight Acceptable stresses Hot/cold oil distress Acceptable stresses & frequencies Forging grain flow as required Adequate material properties Operational effects accounted for Impact testing Risk Mitigation and Control • • • • • • • • • • Unbalance loading Vibration End loading Scuffing Width: proper transition radius Height: enough mass to control deformation Rim resonant vibration, cracking, dysfunction Gear vibratory mode changes due to thickness distribution Weight – excessive inertia load Stress/life Proper bearing preload Correct gear alignment Mechanical/functional, failure due to variation from nominal Poor mechanical or environmental properties Excessive weight Excessive loading on retaining features Undesirable natural frequencies Low material properties: tooth, rim separation Spalling during operation

• • • • • • • • • • • • • 92

Part and System Failure Modes Part and System Failure Modes • • • • • • Shape Surface finish Pitch diameter Contact angle Edge break Tolerance Width Height Transition to rim and hub Thickness distribution Lightning features Dampening features Bearing fit Axial location of gear surface Variance-fluctuations in measurements Measurement gauge repeatability and reliability Major elements - % variation Impurities Density Coefficient of thermal expansion Melting point Modulus Forging grain flow angles Tensile, UTS, YS, elongation, stress rupture, creep, LCF, HCF Sudden overload properties Surface hardness depth Key Characteristics • • • • • • • • • • • • • • • • Key Characteristics • • • • • • • • • • Characteristic Critical to Part Functionality Tooth form Gear rim Web Hub Tolerance Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3

8/19/09

Process control (melt control, cleanliness Process control and sequencing Process control and sequencing Correct sequencing of weld process Process control Process control Process control • • • • • • • Risk Mitigation and Control Verify that variations in grain structure are accounted for Process control and inspection Verify adequate environmental properties Risk Mitigation and Control • • • Crack growth from inclusion or porosity Inadequate material properties Incorrect structure leading to low material properties Material property reduction Weld failure Incorrect compressive stress, cracking Improper case depth Hardness improper Part and System Failure Modes • • • • • • • • Material property reduction due to abnormal grain structure, vibration, Spalling from oxidation/corrosion pitting Property reduction due to extreme oil overtemp or lack of cooling oil Part and System Failure Modes • • •

Processing

–

Inclusions and porosity Micro structural characteristics Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Weld strength Microstructure: grain size, shape, flow, defects, grain boundary precipitates Porosity Heat affected zone Filler metal selection Joint design Intensity Coverage Time @ temperature and ramp rates Manufacturing sequence Atmosphere Tooling and fixturing Key Characteristics • • • • • • Effect on base material properties, based on the following: • • • • • • • • • • • • Grain structure (size, shape, flow, boundaries) Directional properties Hardness Forging laps Homogeneity of forging work throughout part Oxidation, corrosion, fretting resistance Elevated temperature stress relaxation Surface coating Key Characteristics • • • • • • • • Characteristic Critical to Part Functionality Forged structure Environmental resistance Characteristic Critical to Part Functionality Raw material processing Heat treatment Welding Peening Surface hardening AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-4 3-5 Section 4 – Part Materials and Processes Section/ Number 4-1 4-2 4-3 4-4 4-5

8/19/09

Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Process control and sequencing • • • • • Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman diagram Use applicable dA/dN curve Predict K using expected defect size • • • • • • Risk Mitigation and Control Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape” Material property reduction due to abnormal grain structure Part and System Failure Modes • • • • Inadequate part life due to analysis under-predicting part temperature, mechanical stress Inadequate part life due to analysis Using incorrect properties Failing to address the ‘key characteristics’ Resonant vibration, cracking, dysfunction Crack growth from defect • • • • • • Part and System Failure Modes

Processing

–

Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack • • • • • Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Grain structure (size, shape, flow, boundaries) Directional properties Hardness Forging laps Homogeneity of forging work throughout part Torque loads Oil temperatures Speeds Transient loads Temperature effects Overloads FOD impact Temperature effects Vibration and mean stress effects Temperature effects Threshold stress intensity Key Characteristics Micro cracks or recast: Fatigue capability degradation, due to: • • • • • Forging structure • • • • • Key Characteristics • • • • • • • • • • • Characteristic Critical to Part Functionality Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.) and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Forging process Characteristic Critical to Part Functionality Operating conditions LCF life assessment HCF life analysis Fracture mechanics AC 33-8 Appendix 2 Section 4 – Part Materials and Processes Section/ Number 4-6 4-7 4-8 4-9 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 5-4

8/19/09

Perform adequate component and/or engine testing Engine testing Risk Mitigation and Control • • Verify part is tolerant to variation Verify correct inputs to lifing process • • Risk Mitigation and Control Gear dysfunction Excessive vibration Metal particles in oil Accessories not able to be fully loaded • • • • Part and System Failure Modes Inadequate part life due to variation Inadequate part life due to analysis under-predicting • • Part and System Failure Modes Engine operation characteristics Predicted stress and Temperature Material properties Operation during part life Fatigue Tensile strength Tooth alignment Spalling Engine vibration response Microstructure Vibration signature Abnormal gear wear Maximum pad loading Key Characteristics • • • • Key Characteristics • • • • • • • • • Characteristic Critical to Part Functionality Durability Operability and performance Characteristic Critical to Part Functionality Variation Life calculation AC 33-8 Appendix 2 Section 5 – Analysis Section/ Number 5-6 5-7 Section 6 – Testing Section/Number 6-1 6-2

8/19/09

Comments ICAs including on-wing inspection requirements and on-wing limits Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Gear vibration-Design Gear train response Continued integrity Gear release Sudden gear train loading Sudden gear train loading Gear vibration Gear durability Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction: Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35.

AC 33-8 Appendix 2

8/19/09

Gear in-service inspection limits Gear wear must be within serviceable limits Could be affected Could be affected Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Trailing Edge Airfoil Outer spindle Inner spindle Leading Edge Platform Airfoil

(all features may not be applicable)

Bleed feature Trailing Edge

Template #11: Compressor Vane

Squealer Tip

Nomenclature for Generic Component Features

Rails Tip Leading Edge

AC 33-8 Appendix 2

8/19/09

Risk Mitigation and Control Control vane attachment to case clearance Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Verify capability exceeds expected utilization Surface dimensional process control Risk Mitigation and Control Dimensional process control and inspection Dimensional process control Dimensional process control Vane separation from tensile overload Crack growth from LCF, HCF, or HCF/LCF interaction Loss of tip fatigue strength from rubbing Excessive rub load Tip cracking or corner loss Unbalance tang loading/blade dysfunction Incorrect loading on disk/cracking Inability to assemble Excessive clearance/movement leading to vibration and wear Rotor to stator contact Width: binding, recirculation Length: rotor/stator rubs Platform resonant vibration, cracking, dysfunction Inadequate cooling leading to turbine blade dysfunction Incorrect customer bleed Poor operability (TBV) Part and System Failure Modes Vane vibration: Vane or case cracking or wear Vane resonant vibration, cracking, dysfunction • • • • • Part and System Failure Modes • • • • • • • • • • • Vane natural frequencies Vibration stress distribution Cycles to failure demonstration Vibration test set-up and execution criteria, i.e., establishing parameters for vane holding, loading, excitation modes determination, and excitation sensing techniques Vane geometry Material mechanical/metallurgical/physical properties Squealer tip geometry Key Characteristics Vane rail to case clearance • • • • • • • Shape Contour Location relative to airfoil Tolerance (vane root and case slot dimensional spectrums and blade producibility limitations) Width - tangential Length Outer gas path contour Orifice size Flow characteristics Radial location on airfoil where applicable Key Characteristics • • • • • • • • • • Characteristic Critical to Part Functionality Vibration damping Vibration characteristics (HCF capability) LCF, fracture toughness, tensile overload capability Squealer tip Characteristic Critical to Part Functionality Rail/T-slot Platform Bleed off-take AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3

8/19/09

Risk Mitigation and Control Surface dimensional process control Dimensional process control Dimensional process control and inspection of passage geometry Verify part is tolerant to variation Control of manufacturing and inspection processes Dimensional process control and inspection Dimensional process control Poor aero performance Airfoil vibratory mode changes due to thickness distribution Operability issues – stall leading to lack of thrust and potential damage to flowpath hardware FOD tolerance Supply bleed pressure – turbine blade/rotor dysfunction Airfoil stress/life Airfoil stress/life Inadequate cooling leading to turbine blade dysfunction Incorrect customer bleed Poor operability (TBV) Inability to assemble Excessive clearance/movement leading to vibration and wear Excessive drag and bushing wear Rotor to stator contact Incorrect VSV staging leading to airfoil dysfunction or operability or performance issues Failure due to stress concentration Part and System Failure Modes • • • • • • • • • • Mechanical/Functional, failure due to variation from nominal • • • • • • Aero contour/stagger angle Leading edge contour Thickness distribution Chord Passage area and blockage Variance-fluctuations in measurements Measurement gauge repeatability and reliability Shape Location relative to airfoil Alignment of inner/outer trunnions Indexing feature location relative to airfoil Threaded feature and/or insert Filet profile Key Characteristics • • • • Thickness vs chord and span • • • • • • • • • Characteristic Critical to Part Functionality Airfoil external shape Airfoil wall thickness Airfoil internal cavities Tolerance Trunnions/spindles Airfoil to platform filets AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-4 2-5 2-6 2-7 2-8 2-9

8/19/09

Acceptable stresses & frequencies Forging grain flow, as required Adequate material properties Operational effects accounted for Acceptable stresses Vane “fit” in hot condition Risk Mitigation and Control Material selection Process control Verify: • • Verify: • • • • Impact testing Verify that grain structure are accounted for Process control & inspection Verify adequate environmental properties Control of chemistry and application process Verify thermal-mechanical compatibility with base material Verify acceptable wear couple Control of chemistry and application process Verify adequate temperature capability Verify adequate erosion characteristics and base material compatibility Poor mechanical or environmental properties Interference with surrounding hardware Undesirable natural frequencies Low material properties, vane dysfunction Material capability consumed in operation Material property reduction due to abnormal grain structure, Vane dysfunction Cracking from oxidation/corrosion pitting, vane dysfunction Property reduction due to brittle Alpha case, vane dysfunction Cracking from corrosion pitting Performance and operability degradation Vane dysfunction due to material property degradation Part and System Failure Modes • • • • • • • • • Loss of material leading to dysfunction of vane and/or case • • Major elements - % variation Impurities Density Coefficient of thermal expansion Melting Point Modulus Forging grain flow angles Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF) Long term metallurgical stability Impact properties Grain structure (size, shape, flow, boundaries Directional properties Hardness Forging laps Homogeneity of forging work throughout part Oxidation, corrosion, erosion, fretting resistance Elevated temperature stress relaxation, alpha case formation) Rubbing, FOD resistance Coverage and thickness Long term stability Corrosion resistance Rub rate (clearances, relative motion) Environment (température, pressure) Material of adjacent hardware Wear resistance and abrasiveness Coverage and thickness Temperature capability Erosion resistance Compatibility with base material Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Forged structure Environmental resistance Environmental coating Ti Fire resistance Rail/T-slot/trunnion wear coating Erosion coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9

8/19/09

Risk Mitigation and Control Process control (melt control, cleanliness) Process control and sequencing Process control and sequencing Correct sequencing of braze or weld cycles in the process Process control Process control Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Process control and sequencing Crack growth from inclusion or porosity Inadequate material properties and vane blade dysfunction Material property reduction Braze or weld failure leading to separation of vane assembly Part and System Failure Modes • • Incorrect structure leading to low material properties • • Incorrect rail/T-slot/trunnion compressive stress, cracking, vane dysfunction Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, vane dysfunction Material property reduction due to abnormal grain structure, vane dysfunction Inclusions and porosity Microstructural characteristics Time @ temperature and ramp rates Manufacturing sequence Atmosphere Weld or braze strength Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitate) Porosity Diffusion zone (brazing) Heat affected zone (welding) Penetration (welding) Excess braze allowance Filler metal selection Intensity Coverage Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Grain Structure (size, shape, flow, boundaries) Directional properties Hardness Forging laps Homogeneity of forging work throughout part Key Characteristics • • • • • Effect on base material properties, based on the following: • • • • • • • • • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Forging structure: • • • • • Welding and brazing Characteristic Critical to Part Functionality Raw material processing Heat treatment Peening Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.)and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Forging process AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8

8/19/09

Risk Mitigation and Control Perform adequate component and engine testing Engine testing Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman diagram Use applicable dA/dN curve Predict K using expected defect size Verify part is tolerant to variation Verify correct inputs to lifing process Stall leading to lack of thrust and potential damage to flowpath hardware Unacceptable acceleration rate Unacceptable range and loading capability Part and System Failure Modes Vane dysfunction • • • Using incorrect properties Failing to address the ‘key characteristics’ Part and System Failure Modes Inadequate part life due to analysis under-predicting part temperature, mechanical stress Inadequate part life due to analysis • • Vane resonant vibration, cracking, dysfunction Crack growth from defect Inadequate part life due to variation Inadequate part life +-due to analysis under-predicting Flow path temperatures, pressures, and velocities Temperature effects Hold time effects Mean stress effects Notch effects Coating effects Mesh size Temperature effects Vibration and mean stress effects Temperature effects Threshold stress intensity Vane or engine characteristics Predicted stress and temperature Material properties Operation during part life Key Characteristics • • • • • • • • • • • • • • • Fatigue Corrosion (hot and cold) Erosion Tensile strength Ballistic capability Engine Aeromechanical response Microstructure Stall margin Acceleration rates SFC Thrust Key Characteristics • • • • • • • • • • • Characteristic Critical to Part Functionality Operating conditions LCF life assessment HCF life analysis Fracture mechanics Variation Life calculation Characteristic Critical to Part Functionality Durability Operability and performance AC 33-8 Appendix 2 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 5-4 5-5 5-6 Section 6 – Testing Section/ Number 6-1 6-2

8/19/09

Comments ICAs including on-wing inspection requirements and on-wing limits Titanium fire Could be affected Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart – A General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Vane vibration-Design Compressor stall line - Operating line migration due to erosion Pressure at bleed location Bleed temperature impacts icing system Compressor efficiency/performance Compressor blade release-Case containment Compromised aero – missing airfoil Compromised aero – missing airfoil Vane vibration-Demonstration test Vane durability Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35.

AC 33-8 Appendix 2

8/19/09

Vane in-service inspection limits Could be affected Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Airfoil

Platform

Shrouds

Dovetail

Squealer Tip

Leading Edge

(all features may not be applicable)

Template #12: Compressor Blade

Nomenclature for Generic Component Features

Shank

Tip Caps

Trailing Edge

AC 33-8 Appendix 2

8/19/09

Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman Diagram limits Surface dimensional process control Verify acceptable wear couple Risk Mitigation and Control Surface dimensional process control Surface dimensional process control • • Verify capability exceeds expected utilization • • Surface dimensional process control Blade separation from tensile overload Crack growth from LCF, HCF, or HCF/LCF interaction Loss of tip fatigue strength from rubbing Blade vibration: airfoil cracking Blade dysfunction during FOD event Excessive rub load Tip cracking or corner loss Part and System Failure Modes Dovetail and disk loading-dysfunction Dovetail and disk loading-dysfunction Blade resonant vibration, cracking, dysfunction • • • • • • • As-forged surfaces Machined surfaces As-forged surfaces Machined surfaces Mass/density distribution Blade natural frequencies Vibration stress distribution Cycles to failure demonstration Vibration test set-up and execution criteria, i.e., establishing parameters for blade holding, loading, excitation modes determination, and excitation sensing techniques Blade geometry Material mechanical/metallurgical/physical properties Shroud geometry Shroud location on airfoil Wear resistance on mating component Squealer tip geometry Key Characteristics • • • • • • • • • • • • • • • Axial Tangential Radial Characteristic Critical to Part Functionality Weight Moment of weight - center of gravity • • • Vibration characteristics (HCF capability) LCF, fracture toughness, tensile overload capability Part span shrouds Squealer tip AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5 1-6

8/19/09

Verify part is tolerant to variation Control of manufacturing and inspection processes Dimensional process control Risk Mitigation and Control Dimensional process control and inspection Dimensional process control Surface dimensional process control • • • Unbalance tang loading/blade dysfunction Incorrect loading on disk/cracking Width: binding, recirculation Length: rotor/stator rubs Platform resonant vibration, cracking, dysfunction Poor aero performance Airfoil vibratory mode changes due to thickness distribution Operability issues – stall leading to lack of thrust and potential damage to flowpath hardware FOD tolerance Supply bleed pressure – insufficient mass flow to turbine blade and/or rotor cavity leading to turbine blade/rotor dysfunction Weight - Dovetail and disk loading-dysfunction Airfoil stress/life Part and System Failure Modes • • • • • • • • • • • • Mechanical/functional, failure due to variation from nominal Failure due to stress concentration Shape Surface contour Tang relative location and taper Tolerance (blade root and disk slot dimensional spectrums and blade producibility limitations) Width Length Inner gas path contour Aero contour/stagger angle Leading edge contour Thickness distribution Chord Variance-fluctuations in measurements Measurement gauge repeatability and reliability Filet profile Key Characteristics • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Dovetail Platform Airfoil external shape Tolerance Airfoil to platform filets AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5

8/19/09

Acceptable stresses and frequencies Forging grain flow as required Adequate material properties Operational effects accounted for Impact testing Acceptable blade weight Acceptable stresses Blade “fit” in hot condition Risk Mitigation and Control Material selection Process control Verify: • • • Verify: • • • • • Verify that variations in grain structure are accounted for Process control and inspection Verify adequate environmental and wear properties Control of chemistry and application process Verify thermal-mechanical compatibility with base material Verify acceptable wear couple Control of chemistry and application process Verify adequate temperature capability Verify adequate erosion characteristics and base material compatibility Poor mechanical or environmental properties Excessive blade weight Interference with surrounding hardware Undesirable natural frequencies Low material properties, blade dysfunction Material capability consumed in operation Cracking from oxidation/corrosion pitting, blade dysfunction Property reduction due to brittle Alpha case, blade dysfunction Loss of material leading to dysfunction of blade and/or disk Unbalanced loading leading to dysfunction of blade and/or disk Performance and operability degradation Blade dysfunction due to material property degradation Part and System Failure Modes • • • • • • Material property reduction due to abnormal grain structure, blade dysfunction • • Cracking from corrosion pitting • • • • Major elements - % variation Impurities Density Coefficient of thermal expansion Melting point Modulus Forging grain flow angles Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF) Long term metallurgical stability Impact properties Grain structure (size, shape, flow, boundaries) Directional properties Hardness Forging laps Homogeneity of forging work throughout part Oxidation, corrosion, erosion, fretting resistance Elevated temperature stress relaxation, alpha case formation) Rubbing, FOD resistance Coverage and thickness Long term stability Corrosion resistance Rub rate (clearances, relative motion) Environment (temperature, pressure) Material of adjacent hardware Wear resistance and abrasiveness Coverage and thickness Temperature capability Erosion resistance Compatibility with base material Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Forged structure Environmental resistance Environmental coating Ti Fire resistance Dovetail anti-fret coating Erosion coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9

8/19/09

Risk Mitigation and Control Process control (melt control, cleanliness) Process control and sequencing Process control and sequencing Correct sequencing of braze cycles in the process Process control Process control Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Process control and sequencing Crack growth from inclusion or porosity Inadequate material properties and blade dysfunction Material property reduction Braze failure and loss of mid-span wear pad Part and System Failure Modes • • Incorrect structure leading to low material properties • • Incorrect dovetail compressive stress, cracking, and blade dysfunction Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, blade dysfunction Material property reduction due to abnormal grain structure, blade dysfunction Inclusions and porosity Microstructural characteristics Time @ temperature and ramp rates Manufacturing sequence Atmosphere Braze strength Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitates) Porosity Diffusion zone (brazing) Excess braze allowance Filler metal selection Intensity Coverage Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Grain Structure (size, shape, flow, boundaries) Directional properties Hardness Forging laps Homogeneity of forging work throughout part Key Characteristics • • • • • Effect on base material properties, based on the following: • • • • • • • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Forging structure • • • • • Characteristic Critical to Part Functionality Raw material processing Heat treatment Brazing Peening Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.)and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and Substantiation Forging process AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8

8/19/09

Use applicable properties Select mesh size to correctly model the geometry Use applicable dA/dN curve Predict K using expected defect size Risk Mitigation and Control Perform analysis at relevant operating conditions • • Use applicable properties and Goodman diagram Use applicable properties • • Verify part is tolerant to variation Verify correct inputs to lifing process Using incorrect properties Failing to address the ‘key characteristics’ Part and System Failure Modes Inadequate part life due to analysis under-predicting part temperature, mechanical stress Inadequate part life due to analysis • • Blade resonant vibration, cracking, dysfunction Blade rupture cracking, dysfunction Crack growth from defect Inadequate part life due to variation Inadequate part life due to analysis under-predicting Flow path temperatures, pressures, and velocities Rotor speed Temperature effects Hold time effects Mean stress effects Notch effects Coating effects Mesh size Temperature effects Vibration and mean stress effects Temperature effects Material thickness effects Temperature effects Threshold stress intensity Blade or engine characteristics Predicted stress and temperature Root loading profile shifts Material properties Operation during part life Life impact on disk Key Characteristics • • • • • • • • • • • • • • • • • • • •

Analysis

–

Characteristic Critical to Part Functionality Operating conditions LCF life assessment – airfoil and shank HCF life analysis Creep and rupture life analysis Fracture mechanics Variation Life calculation

AC 33-8 Appendix 2 Section 5 Section/ Number 5-1 5-2 5-3 5-4 5-5 5-6 5-7

8/19/09

Risk Mitigation and Control Perform adequate component and/or engine testing Engine testing Comments ICAs including on-wing inspection requirements and on-wing limits Stall leading to lack of thrust and potential damage to flowpath hardware Unacceptable acceleration rate Unacceptable range and loading capability Part and System Failure Modes Blade dysfunction • • • Could be affected Fatigue Corrosion (hot and cold) Erosion Creep Tensile strength Ballistic capability Engine Aeromechanical response Microstructure Stall margin Acceleration rates SFC Thrust Key Characteristics • • • • • • • • • • • • the engine Characteristic Critical to Part Functionality Durability Operability and Performance Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4.

AC 33-8 Appendix 2 Section 6 – Testing Section/ Number 6-1 6-2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Weight and center-of-gravity affect on rotor forces and LCF capability Titanium fire Weight affect on rotor forces during over-speed Rotor stress analysis Blade vibration-Design Compressor stall line - Operating line migration due to erosion Pressure at bleed location Bleed temperature impacts icing system Compressor efficiency/performance Compressor blade release-Case containment Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected supercharger rotors Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

AC 33-8 Appendix 2

8/19/09

Compromised aero – missing airfoil Compromised aero – missing airfoil Blade vibration Blade durability Blade in-service inspection limits Failure of the most critical compressor blade while operating at maximum permissible r.p.m.

Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) (Weight changes) mode Subpart E – Design and Construction; Turbine Aircraft Engines 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

(all features may not be applicable)

Template #13: Static Air Seal

Nomenclature for Generic Component Features

Honeycomb/Rubber/Teflon on Sheet metal/Machined Forging

AC 33-8 Appendix 2

8/19/09

Verify part is tolerant to variation Control of manufacturing and inspection processes Dimensional process control and inspection geometry Dimensional process control and inspection geometry Dimensional process control and inspection geometry Dimensional process control and inspection geometry Risk Mitigation and Control Verify capability exceeds expected utilization Verify compatibility to rotating seal Verify compatibility to rotating seal Risk Mitigation and Control • • • • • • Seal failure. Excessive contact. Rotating part dysfunction Thermal instability. Rotating part dysfunction Rotating seal tooth cracking. Rotating part dysfunction Excessive seal wear/leakage Thermal instability. Rotating part dysfunction Rotating seal tooth cracking. Rotating part dysfunction Excessive seal wear/leakage Part and System Failure Modes • • • • • • • Part and System Failure Modes Mechanical/Functional, failure due to variation from nominal Excessive wear, looseness of fit, excessive seal clearance, performance impact Arch-binding, mechanical failure due to excessive seal rub, rotating part dysfunction Failure to seal, performance impact Excess rub, rotating part dysfunction Fatigue failure Arch-binding, mechanical failure due to excessive seal rub, rotating part dysfunction Material mechanical/metallurgical/physical properties Material mechanical/physical properties Machinabilty by rotating seal teeth Environmental temperature capability Material mechanical/metallurgical/physical properties Machinabilty by rotating seal teeth Foil thickness. cell size. braze wicking Key Characteristics • • • • • • • Variance-fluctuations in measurements Measurement gauge repeatability and reliability Thickness Axial length Radius Location Bearing surface area Crimping Inner diameter Cell depth Arc length Inner diameter Key Characteristics • • • • • • • • • • • • Characteristic Critical to Part Functionality Tensile capability Abradability-solid Cutting characteristics- honeycomb Characteristic Critical to Part Functionality Tolerance Retention/hook geometry Anti-rotation feature Honeycomb/ abradable geometry Backing plate geometry AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5

8/19/09

Correct sequencing of braze cycles in the process Process control Verify part is tolerant to proposed limits Process control Risk Mitigation and Control Process control and sequencing • • • • Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Acceptable stresses Adequate material properties Operational effects accounted for Relevant properties are used Acceptable stresses Seal “fit” in hot condition Risk Mitigation and Control Material selection Verify: • • Verify: • • • • Verify adequate environmental properties Part and System Failure Modes Low material properties Material property reduction, braze failure Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, seal dysfunction Poor mechanical or environmental properties Interference with surrounding hardware Low material properties Material capability consumed in operation Low material properties, seal dysfunction Part and System Failure Modes • • • • • Cracking from oxidation/corrosion pitting, seal dysfunction Time @ temperature and ramp rates Manufacturing sequence Atmosphere Braze strength Microstructure, braze gap, defects, Porosity Diffusion zone (brazing) Excess braze allowance Filler metal selection Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Key Characteristics • • • Effect on base material properties, based on the following: • • • • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Major elements - % Variation Impurities Thermal conductivity Coefficient of thermal expansion Wrought structure Hardness/grain size Modulus Tensile (UTS, YS) Long term metallurgical stability Oxidation, corrosion, erosion, fretting resistance Key Characteristics • • • • • • • • • • Characteristic Critical to Part Functionality Heat treatment Brazing Material removal – Non traditional (EDM, ECM, Laser, Water-Jet) and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical properties Environmental resistance AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3 4-4 4-5

8/19/09

Risk Mitigation and Control Risk Mitigation and Control Perform analysis at relevant operating conditions Verify part is tolerant variation Verify correct inputs to life calculation Part and System Failure Modes Inadequate part life due to analysis under-predicting part temperature, thermal or mechanical stress Inadequate part life Inadequate part life due to analysis under-predicting Part and System Failure Modes Cavity temperatures, pressures, Dimensional characteristics Calculated stress and Temperature Material properties Operating during part life Key Characteristics • • • • • Fatigue Tensile strength Cleaning requirements Key Characteristics • • • Characteristic Critical to Part Functionality Operating conditions Variation Life calculation Characteristic Critical to Part Functionality Durability Bond Strength AC 33-8 Appendix 2 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 Section 6 – Testing Section/ Number 6-1 6-2

8/19/09

Comments Could be affected Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Durability Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36.

AC 33-8 Appendix 2

8/19/09

Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

(all features may not be applicable)

Template #14: VSV Lever Arms

Nomenclature for Generic Component Features

AC 33-8 Appendix 2

8/19/09

Dimensional process control and inspection Dimensional process control and inspection Dimensional process control and inspection Dimensional process control and inspection Risk Mitigation and Control Verify capability Verify compatibility in operating environment Verify dimensional characteristics Risk Mitigation and Control • • • • Dysfunction of actuation system leading to stall, component failure Dysfunction of actuation system leading to stall, component failure Dysfunction of actuation system due to lever arm fatigue or excessive wear Part and System Failure Modes • • • Part and System Failure Modes Incorrect fit leading into fretting at vane interface Excessive wear lead into vane actuation failure Fatigue failure Incorrect VSV travel leading to stall Incorrect VSV travel leading to stall Dysfunction of lever arm through tensile, LCF or HCF Interference with case feature leading to limited travel Material mechanical/metallurgical/physical properties Compatibility of lever arm and pin material Relative radial position of interface surfaces Key Characteristics • • • Width Thickness Corner radii Location relative to slot Diameter Location relative to slot Allowable misalignment Cross sectional properties Key Characteristics • • • • • • • • Characteristic Critical to Part Functionality LCF, HCF, tensile capability Galvanic corrosion Radial preload Characteristic Critical to Part Functionality Slot Pin Spherical bearing Web geometry AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4

8/19/09

Verify part is tolerant to proposed limits Process control Risk Mitigation and Control Process control and sequencing Process control • • Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Verify adequate control of processes and parameters Acceptable stresses Adequate material properties Operational effects accounted for Relevant properties are used Acceptable stresses Lever arm “fit” in hot condition Risk Mitigation and Control Material selection and process control Verify: • • Verify: • • • • Verify acceptable galvanic couples Part and System Failure Modes Incorrect morphology leading to low material properties Fatigue capability degradation lead to potential lever arm dysfunction Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, bushing dysfunction Inadequate assembly lead to wear/fatigue cracking and riveted joint dysfunction Poor mechanical or environmental properties Excessive stresses Interference with surrounding hardware Excessive strain-controlled stress Undesirable natural frequency Low material properties Part and System Failure Modes • • • • • • Cracking at pin/arm interface due to galvanic attack Time @ temperature and ramp rates Manufacturing sequence Intensity Coverage Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation Head and hole geometry Assembled condition Key Characteristics • • • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • • • Major elements - % variation Impurities Coefficient of thermal expansion Modulus Wrought structure Hardness/grain size Compressive/tensile (UTS, YS) LCF, HCF Long term metallurgical stability Corrosion Key Characteristics • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Environmental resistance Characteristic Critical to Part Functionality Heat treatment Shot peen Material removal - Non traditional - Conventional machining Non-destructive testing (NDT) Process sequencing including coating Significant process identification and substantiation Pin riveting AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3 4-4 4-5 4-6

8/19/09

Risk Mitigation and Control Component test Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Verify part is tolerant to variation Verify correct inputs to lifing process Using incorrect properties Failing to address the ‘key characteristics’ Part and System Failure Modes Inadequate part life due to analysis under-predicting part temperature or mechanical stress Inadequate part life due to analysis • • Inadequate part life due to variation Inadequate part life due to analysis under-predicting Part and System Failure Modes Mechanical load and temperature Temperature effects Mean/alternating stress effects Notch effects Coating effects Mesh size Lever arm characteristics Predicted stress and temperature Material properties Operating during part life Key Characteristics • • • • • • • • • • Fatigue Key Characteristics • Characteristic Critical to Part Functionality Operating conditions LCF life analysis Variation Life calculation Characteristic Critical to Part Functionality Durability AC 33-8 Appendix 2 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 5-4 Section 6 – Testing Section/ Number 6-1

8/19/09

Comments Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

If vane location and angular tolerance is different, compressor stall margin may be affected. If vane location and angular tolerance is different, blade/vane resonance could be affected. Lever arm Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34.

AC 33-8 Appendix 2

8/19/09

Visual Inspection Could be affected Could be affected Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

Template #15: Bushings

(all features may not be applicable)

Nomenclature for Generic Component Features

Ceramic bushing/ Polymeric bushing/ Metallic bushing

AC 33-8 Appendix 2

8/19/09

Dimensional process control and inspection Dimensional process control and inspection Dimensional process control and inspection Risk Mitigation and Control Verify capability Verify compatibility in operating environment Verify part material and geometry Risk Mitigation and Control • • • Dysfunction of bushing due to cracking from shock load, Severe wear leading to gas leakage Loose fit leading to mating part vibration failure, or rotor and stator contact System seizure-stall, failure of component actuation system Increase wear rate due to excessive drag Loose fit leading to mating part vibration failure, or rotor and stator contact Unacceptable thin bushing due to eccentricity Part and System Failure Modes • • • • • Part and System Failure Modes • • Improper fit leading to premature failure or binding Interference at assembly preventing freedom of movement Coefficient of thermal expansion Cold fit • • Material mechanical/metallurgical/physical properties Wear couple Contact area Coefficient of friction Hot dimensional fit Surface finish Key Characteristics • • • • • • OD, ID, Concentricity Variance-fluctuations in measurements Measurement gauge repeatability and reliability Thickness Flatness Key Characteristics • • • • • Characteristic Critical to Part Functionality Fracture toughness Wear characteristics Freedom of rotation Characteristic Critical to Part Functionality Diameters Tolerance Flange AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3

8/19/09

Risk Mitigation and Control Process control (mold setup, process, and filtration) Process control and sequencing Process control and sequencing Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Acceptable stresses Adequate material properties Operational effects accounted for Relevant properties are used Acceptable stresses Bushing “fit” in hot condition Control of chemistry and application process Verify stability (thermal and chemical) Risk Mitigation and Control Material selection and Process control Verify: • • Verify: • • • • Verify adequate environmental properties • • Part and System Failure Modes Crack growth wear from inclusion or porosity Incorrect morphology leading to low material properties Excessive wear due to rough surface finish Cracking from excessive defect size Inadequate final part form, or defect “escape”, bushing dysfunction Poor mechanical or environmental properties Poor oxidation stability Excessive thermal stresses Interference with surrounding hardware Excessive strain-controlled stress Low material properties Material capability consumed in operation Increased friction load Part and System Failure Modes • • • • • • • Cracking/wear out •

Processing

–

Inclusions and porosity Time @ temperature and ramp rates Manufacturing sequence Atmosphere Surface finish Acceptance limits Sensitivity Inspection Manufacturing Process substantiation Key Characteristics • • • • • • • • • • Major elements - % variation Impurities Coefficient of thermal expansion Modulus Compressive tensile (UTS, YS) Long term metallurgical stability Max temperature capability Oxidation, fretting resistance Rubbing Resistance to solvents Coverage and thickness Long term stability Oxidation resistance Key Characteristics • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Environmental resistance Friction modifier coating Characteristic Critical to Part Functionality Injection molding cleanliness Heat treatment Conventional machining Non-destructive testing (NDT) Process sequencing including coating Significant process identification and substantiation

/

AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5 Section 4 – Part Materials and Processes Section Number 4-1 4-2 4-3 4-4 4-5

8/19/09

Risk Mitigation and Control Component test Risk Mitigation and Control Perform analysis at relevant operating conditions Verify part is tolerant to variation Verify correct inputs to calculation Comments Part and System Failure Modes Part and System Failure Modes Inadequate part life due to analysis under-predicting part temperature or mechanical stress Inadequate part life due to variation Inadequate part life due to excessive wear Could be affected Mechanical load and temperature Bushing characteristics Predicted stress and temperature Material properties Tensile strength Wear Rate Oxidation Key Characteristics • • • • Key Characteristics • • • the engine Characteristic Critical to Part Functionality Operating conditions Variation Crush stress calculation Characteristic Critical to Part Functionality Durability Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4.

AC 33-8 Appendix 2 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 Section 6 – Testing Section/ Number 6-1 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Could be affected Could be affected supercharger rotors Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26.

AC 33-8 Appendix 2

8/19/09

Bushing Could be affected Could be affected ingestion) of ingestion) (Weight changes) mode Subpart E – Design and Construction; Turbine Aircraft Engines 33.76 Bird Ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

l

Trailing Edge (TE) Airfoi Pressure Side Bleed (PSB) Slots Platform Platform Rail (Skirt) Pressure Face Film Cooling Holes Squealer Tip Dovetail

(all features may not be applicable)

Template #16: Turbine Blade Cooled

Tip Dust/Cooling Holes

Nomenclature for Generic Component Features

Shank Tip Caps LE Radial Film Holes Axial Gill Holes Damper/Seal Retention Lugs Leading Edge (LE) Angel Wing

AC 33-8 Appendix 2

8/19/09

Risk Mitigation and Control Surface dimensional process control Surface dimensional process control Control damper seating with blade and/or disk Resonance avoidance at steady state operation with margin Vibratory and steady state stress within Goodman diagram limits Verify capability exceeds expected utilization Low flow: blade over-temperature/dysfunction High flow: reduced rotor cavity purge/ingestion/part dysfunction Poor distribution of cooling air: over-temperature, and existing bench flow limits not valid Blade separation from tensile overload Crack growth from LCF or creep – rupture Loss of tip fatigue strength from rubbing Part and System Failure Modes Dovetail and disk loading-dysfunction Dovetail and disk loading-dysfunction • • • Blade vibration: blade or disk dovetail cracking Blade resonant vibration, cracking, dysfunction • • • As-cast surfaces Machined surfaces As-cast surfaces Machined surfaces Mass/density distribution Total flow rate Individual circuit-cavity flow rate Flow distribution Static pressure distribution Discharge pressure at showerhead, relative to turbine gas flow pressure Damper fit to blade Damping ratio Blade natural frequencies Vibration stress distribution Cycles to failure demonstration Vibration test set-up and execution criteria, i.e., establishing parameters for blade holding, loading, excitation modes determination, and excitation sensing techniques Blade geometry Blade cooling Material mechanical/metallurgical/physical properties Blade cleaning requirements/effectiveness (internal passages-intergranual attack) Key Characteristics • • • • • • • • • • • • • • • • • • • • Axial Tangential Radial Characteristic Critical to Part Functionality Weight Moment of weight - center of gravity • • • Cooling air utilization Vibration damping Vibration characteristics (HCF capability) Creep, LCF, fracture toughness, tensile overload capability AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5 1-6

8/19/09

Verify part is tolerant to variation Control of manufacturing and inspection processes Dimensional process control Risk Mitigation and Control Dimensional process control and inspection Dimensional process control Surface dimensional process control Dimensional process control Dimensional process control and inspection of passage geometry • • • Unbalance tang loading/blade dysfunction Incorrect loading on disk/cracking Width: binding/damping loss, leakage/cavity ingestion Angel wing: cavity ingestion or rotor/stator rubs Poor aero performance Airfoil vibratory mode changes due to thickness distribution Blade throat area – Bearing load, cavity purge, operability, work split, stage loading Weight Airfoil stress/life Small area: large pressure loss, backflow, ingestion, over- temperature Large area: Insufficient blade cooling Part and System Failure Modes • • • • • • • • • • • Mechanical/functional, failure due to vibration from nominal Failure due to stress concentration Shape Flatness Tang relative location and taper Tolerance (blade root and disk fir tree dimensional spectrums and blade producibility limitations) Width Angel wing length Inner gas path contour Sealing surfaces, surface finish Aero contour/stagger angle Thickness distribution Passage area and blockage Turbulator height and shape Internal wall coating Variance-fluctuations in measurements Measurement gauge repeatability and reliability Filet profile Key Characteristics • • • • • • • • • • Thickness vs. chord and span • • • • • • Characteristic Critical to Part Functionality Dovetail Platform Airfoil external shape Airfoil wall thickness Airfoil internal cavities Tolerance Airfoil to platform filets AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 2-5 2-6 2-7

8/19/09

Acceptable stresses and frequencies Grain orientation, as required Adequate material properties Operational effects accounted for Relevant properties are used acceptable blade weight acceptable stresses blade “fit” in hot condition Risk Mitigation and Control Material selection Master heat and process control Verify: • • • Verify: • • • • • Verify that grain orientation or high angle boundaries are accounted for Process control and inspection Verify adequate environmental properties Control of chemistry and application process Verify thermal-mechanical compatibility with base material Poor mechanical or environmental properties Poor TBC adherence Excessive blade weight Excessive thermal stresses Interference with surrounding hardware Excessive strain-controlled stress Undesirable natural frequency Low material properties, blade dysfunction Material capability consumed in operation Low material properties, blade dysfunction LCF property reduction due to poor coating selection/requirements, blade cracking Cracking from oxidation/corrosion pitting Part and System Failure Modes • • • • • • • • • • Material property reduction due to excessive grain angle or high angle boundaries (HAB), blade dysfunction Cracking from oxidation/corrosion pitting, blade dysfunction • • Major elements - % variation Impurities Density Thermal conductivity Coefficient of thermal expansion Refractive Index (x-rays) Melting point Modulus (vs. grain orientation) Columnar crystal orientation angles Bare and coated: tensile (UTS, YS, elongation, stress rupture, creep, LCF, HCF) Long term metallurgical stability Thin wall effects Grain structure (size, shape, flow, boundaries, gamma prime size and volume fraction, recrystallization) High angle boundaries Inclusions Freckling Porosity Directional properties Hardness Melting point Crack propagation rate Refractive index Oxidation, corrosion, erosion, fretting resistance Elevated temperature (creep, diffusion, ageing, temp. gradients) Rubbing, FOD resistance Coverage and thickness Long term stability Oxidation and corrosion resistance Key Characteristics • • • • • • • • • • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Chemistry Physical properties Mechanical /metallurgical properties Cast structure Environmental resistance Environmental coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3 3-4 3-5 3-6

8/19/09

Risk Mitigation and Control Process control (mold setup, casting process, and filtration) Process control and sequencing Process control and sequencing Correct sequencing of braze or weld cycles in the process Process control Risk Mitigation and Control Control of chemistry and application process Verify part is tolerant to missing TBC No high TBC temperatures that accelerate spalling, or molten dirt infiltration Part and System Failure Modes Crack growth from inclusion or porosity Poor coating adhesion, corrosion and oxidation Incorrect Gamma prime size/spacing leading to low material properties Material property reduction Braze failure in ‘ball chute’ or at tip, leading to loss of coolant Part and System Failure Modes High thermal stresses or part temperature, blade dysfunction Inclusions and porosity Internal surface cleanliness Time @ temperature and ramp rates Manufacturing sequence Atmosphere Weld or braze strength Microstructure (grain size, shape, flow, braze gap, defects, grain boundary precipitates, gamma prime and volume fraction) Porosity Diffusion zone (brazing) Heat affected zone (welding) Penetration (welding) Excess braze allowance Filler metal selection Key Characteristics • • • • • Effect on base material properties, based on the following: • • • • • • • • Coating material composition and density Thermal conductivity (coefficient of thermal expansion) Coverage and thickness uniformity Coating and diffusion zone microstructure Adhesion Oxidation Resistance to spalling, sindering, and erosion Hardness Residual stress Stripping requirements Bonding (interface contamination) Compatibility with base material/other coatings Key Characteristics • • • • • • • • • • • • Characteristic Critical to Part Functionality Casting cleanliness Heat treatment Welding and brazing Characteristic Critical to Part Functionality Thermal barrier coating AC 33-8 Appendix 2 Section 3 – Part Materials and Processes – Properties Section/ Number 3-7 Section 4 – Part Materials and Processes - Processing Section/ Number 4-1 4-2 4-3

8/19/09

Risk Mitigation and Control Process control Verify part is tolerant to proposed limits Process control Verify part is tolerant to allowable defects Verify adequate control of processes and parameters Risk Mitigation and Control Perform analysis at relevant operating conditions Use applicable properties Select mesh size to correctly model the geometry Use applicable properties and Goodman diagram Use applicable properties Use applicable dA/dN curve Predict K using expected defect size Part and System Failure Modes Incorrect dovetail compressive stress, cracking, and blade dysfunction Cracking initiation from micro-cracks or re-cast Cracking from excessive defect size Inadequate final part form, or defect “escape”, blade dysfunction Using incorrect properties Failing to address the ‘key characteristics’ Part and System Failure Modes Inadequate part life due to analysis under-predicting part temperature, thermal or mechanical stress Inadequate part life due to analysis over-predicting the blade cooling Inadequate part life due to analysis • • Blade resonant vibration, cracking, dysfunction Blade rupture cracking, dysfunction Crack growth from defect Intensity Coverage Inherent to the process Due to abusive machining Surface finish Stress risers Chemical attack Acceptance limits Sensitivity Inspection Manufacturing Process substantiation and control (RSS,RSA,ESA, etc) Key Characteristics • • Micro cracks or recast: • • Fatigue capability degradation, due to: • • • • • • • • Flow path temperatures, pressures, and velocities Rotor speed Secondary flow circuit Blade cooling flow blade cooling Temperature effects Multi-axial effects Hold time effects Mean stress effects Notch effects Coating effects Mesh size Temperature effects Vibration and mean stress effects Temperature effects Material thickness effects Temperature effects Threshold stress intensity Crack growth rate Key Characteristics • • • • • • • • • • • • • • • • • • • Characteristic Critical to Part Functionality Shot peen Material removal – Non traditional (EDM, ECM, laser, water-jet, etc.) and conventional (machining, milling, broaching, grinding, blending, honing, lapping, stripping, etc.) Non-destructive testing (NDT) Process sequencing and significant process identification and substantiation Characteristic Critical to Part Functionality Operating conditions Blade cooling LCF life analysis – airfoil and shank HCF life analysis Creep and rupture life analysis Fracture mechanics AC 33-8 Appendix 2 Section 4 – Part Materials and Processes - Processing Section/ Number 4-4 4-5 4-6 4-7 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 5-4 5-5 5-6

8/19/09

Risk Mitigation and Control Risk Mitigation and Control Perform analysis with predicted TBC loss Verify part is tolerant to vibration Verify correct inputs to lifing process Verify correct ‘mission mixing’ used Part and System Failure Modes Part and System Failure Modes High thermal stress or part temperature, blade dysfunction Inadequate part life due to vibration Inadequate part life due to analysis under-predicting Part temperature Thermal stress Blade or engine characteristics Predicted stress and temperature Root loading profile shifts Material Properties Operating during part life Life impact on disk Key Characteristics • • • • • • • • Fatigue Corrosion (hot and cold) Erosion Creep Stress rupture Tensile strength Cooling effectiveness Internal contamination Cleaning requirements Microstructure Creep Hot corrosion Tensile strength Key Characteristics • • • • • • • • • • • • • Characteristic Critical to Part Functionality Tolerance to missing TBC Variation Life calculation Characteristic Critical to Part Functionality Durability Over-temperature AC 33-8 Appendix 2 Section 5 – Analysis Section/ Number 5-7 5-8 5-9 Section 6 – Testing Section/ Number 6-1 6-2

8/19/09

Comments ICAs including on-wing inspection requirements and on-wing limits Weight and center-of-gravity affect on rotor forces and LCF Capability Weight affect on rotor forces during over-speed Could be affected Could be affected Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Blade vibration-Design Turbine effective area-Operating line migration, Blade-Rub strip interaction Turbine efficiency/performance Turbine blade release-Case containment Blade vibration- Blade durability Blade over temperature capability Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain and hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35.

AC 33-8 Appendix 2

8/19/09

Blade in-service inspection limits Failure of the most critical turbine blade while operating at maximum permissible r.p.m.

Could be affected Could be affected Could be affected (Weight changes) mode 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

8/19/09

(typical) Epoxy bonds (typical) Anti-rotation tang height Overall Overall diameter glands

Template #17: Fuel Filter

Seal/seal

(all features may not be applicable)

Nomenclature for Generic Component Features

assembly (typical) End caps Media support Filtration media Media support mesh AC 33-8 Appendix 2 This template deals with fuel filters which are typically procured under an OEM part number. If the part is listed as a standard part and can be procured commercially, these requirements do not apply.

8/19/09

Dimensional process control and inspection Dimensional process control and inspection Dimensional process control and inspection Dimensional process control and inspection Dimensional process control and inspection • • • • Risk Mitigation and Control • Prevent filter bypass Seal damage/self generated contamination Anti-rotation friction Maintenance/seal installation damage Seal engagement with filter bowl and manifold Inadequate filter bowl/manifold thread engagement External leak/failure Excessive end play/seal wear Installation damage( upper seal blind assembly) Maintenance error/inadequate bowl to manifold engagement Material joining/epoxy joint geometry Installation damage Excessive wear-self generated contamination Fluid velocity/ flow distribution Increased pressure drop Increased filter rotation/ spinning forces • • • • • • • • • • • • • • • • Part and System Failure Modes Form O-ring squeeze Gland fill/ free volume Surface finish Edge condition Form/fit Seal gland inside diameter Upper/lower seal gland concentricity Support core/end cap fit Form Position Filter element/filter bowl clearance Key Characteristics • • • • • • • • • • • • Characteristic Critical to Part Functionality Seal glands Element length End caps Anti-rotation tang Element diameter AC 33-8 Appendix 2 Section 1 – Part Functional capability, i.e., the action(s) that the part is designed to perform in the product Section/ Number 1-1 1-2 1-3 1-4 1-5

8/19/09

Design capability validation Manufacturing acceptance testing Design capability validation Design capability validation Design capability validation Manufacturing acceptance testing • • • • • • Risk Mitigation and Control Design capability validation Design capability validation Design capability validation Risk Mitigation and Control • • • Critical orifice blockage/engine control malfunction Critical valve failure/engine control malfunction Accelerated component wear /component and engine failure Premature filter bypass/control system malfunction Premature filter bypass/control system malfunction High pressure fuel pump inadequate inlet pressure/ cavitation/inadequate capacity Self generating/control system malfunction Release of contamination/control system malfunction Filter element/media failure Self generating contamination/control system malfunction Filter element/media failure Biological growth system fouling Stress corrosion cracking • • • • • • Part and System Failure Modes Part and System Failure Modes • • • • • • • Long term durability Media retention/migration Long term durability Fuel compatibility Temperature capability Adhesive strength Ultimate/tensile strength Oxidation and corrosion resistance Bacterial growth resistance Key Characteristics Greater than 100 per AIR 887 Filter element capacity during design basis contamination event following impending bypass indication Filter element capacity during normal contamination. Normal filter life. Clean element pressure drop Key Characteristics • • • • • • • • • collection / Characteristic Critical to Part Functionality Filtration rating/ efficiency Filter media surface area sites Filter media surface area/collection sites Filet media surface area Characteristic Critical to Part Functionality Media mechanical properties Material joining epoxy Environmental resistance AC 33-8 Appendix 2 Section 2 – Part Shape, size, dimensions and other physical measurable parameters, and interconnectivity with an engine integral part/system Section/ Number 2-1 2-2 2-3 2-4 Section 3 – Part Materials and Processes – Properties Section/ Number 3-1 3-2 3-3

8/19/09

Process definition and control Process definition and control Process sampling/destructive testing Process definition and control Process definition and control Process sampling/destructive testing • • • • • • Risk Mitigation and Control CFD analysis at maximum flow conditions Strength analysis at worst case filter differential pressure with 2X safety margin Dimensional stack-up analyses “Murphy proofing” Dimensional stack-up analyses “Murphy proofing” • • • • • • Risk Mitigation and Control Self generating contamination/control system malfunction Release of contaminant/control system malfunction Filter element/media failure Self generating contamination / control system malfunction Filter element / media failure Media sheath failure / self generated contamination Stress corrosion cracking Filter element / media failure Self generating contamination / control system malfunction Part and System Failure Modes • • • • • • • • • Element rotation/spinning Media distortion/flow impingement effects Filter element/media failure Release of contaminants Filter bowl threads not completely engaged /bowl release / thread failure Filter crushed during installation / ineffective filtration / self generated contamination Filter bowl threads not completely engaged /bowl release / thread failure Filter crushed during installation / ineffective filtration / self generated contamination • • • • • • • • Part and System Failure Modes Chemical/material composition Drying/baking Surface finish Surface cleanliness Epoxy shelf life/batch quantities Curing process temperature and time control Wire mesh sintering process Mechanical preparation/ loose ends from mesh Stabilization/heat treat Effects on base materials Weld or braze strength Key Characteristics • • • • • • • • • • • Inlet fluid velocity distribution Rotational forces Support core strength Axial clearance Full bowl thread engagement/assured O-ring fretting/wear minimized Radial clearance/seal concentricity upper seal self aligning Filter element can not be reversed or is fully reversible Key Characteristics • • • • • • • • Characteristic Critical to Part Functionality Filtration media manufacture Material joining epoxy Filter media mesh sheath Welding and brazing Characteristic Critical to Part Functionality Operating conditions Plugged filter crush resistance Installation dimensional stack up “Murphy proof” installation AC 33-8 Appendix 2 Section 4 – Part Materials and Processes – Processing Section/ Number 4-1 4-2 4-3 4-4 Section 5 – Analysis Section/ Number 5-1 5-2 5-3 5-4

8/19/09

Design assurance (glass bead test) Product acceptance test Design assurance test Specific contaminant makeup, concentration and duty cycle Design operating life demonstration at elevated fuel temperatures Design assurance test at greater than 2X maximum filter differential pressure Design assurance test Product acceptance test • • • • • • • • Risk Mitigation and Control Critical orifice blockage/engine control malfunction Critical valve failure/engine control malfunction Accelerated component wear/component and engine failures Premature filter bypass/control system malfunction Filter element/media failure Release of contaminants Filter element/media failure Release of contaminants High pressure fuel pump inadequate inlet pressure/cavitation/inadequate pumping capacity • • • • • • • • • Part and System Failure Modes Greater than 100 per AIR 887 Filter element capacity during severe contamination event / time from impending bypass indication No media migration or contaminant release during long term exposure to hot fuel Support core test New filter element pressure drop at maximum fuel flow and specified temperature Key Characteristics • • • • • Characteristic Critical to Part Functionality Filter rating/ efficiency Filter capacity test Filter durability Filter crush test Clean element pressure drop

/

AC 33-8 Appendix 2 Section 6 – Testing Section Number 6-1 6-2 6-3 6-4 6-5

8/19/09

Comments ICAs including on-wing inspection requirements No fluid leakage Could be affected Could be affected Could be affected Could be affected the engine supercharger rotors Applicable 14 CFR Part 33 Regulatory Requirements Subpart A – General 33.4 Instructions for Continued Airworthiness 33.5 Instruction manual for installing and operating 33.7 Engine ratings and operating limitations 33.8 Selection of engine power and thrust ratings Subpart B – Design and Construction; General 33.14 Start-stop cyclic stress (low cycle fatigue) 33.15 Materials 33.17 Fire prevention 33.19 Durability 33.21 Engine cooling 33.23 Engine mounting attachments and structure 33.25 Accessory attachments 33.27 Turbine, compressor, fan, and turbo- 33.28 Electrical and electronic control systems 33.29 Instrumentation connection Note: The regulatory requirements identified below, which are inclusive up to Amendment 20 of 14 CFR part 33, are intended as a guide to applicants when determining the applicable regulations to which they must show compliance. Those requirements listed as “Could be affected” highlight the regulations whose compliance findings are typically affected by the component or part that this template is addressing. This guide is not all-inclusive and the applicant remains responsible for identifying the certification basis of the product on which their PMA part is to be installed.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

AC 33-8 Appendix 2 Section 7 – Potential Impact on Regulatory Requirements

8/19/09

Proper flow at temperature extremes Proper fuel flow Could be affected Could be affected Could be affected ingestion) of ingestion) Subpart E – Design and Construction; Turbine Aircraft Engines 33.62 Stress analysis 33.63 Vibration 33.65 Surge and stall characteristics 33.66 Bleed air systems 33.67 Fuel system 33.68 Induction system icing (Operability aspects) 33.69 Ignition system 33.71 Lubrication system 33.72 Hydraulic actuating system 33.73 Power or thrust response 33.74 Continued rotation 33.75 Safety analysis 33.76 Bird ingestion (Operability aspects of 33.77 Foreign object ingestion (Operability aspects 33.78 Rain hail ingestion 33.79 Fuel burning thrust augmenter Subpart F – Block Tests; Turbine Aircraft Engines 33.83 Vibration test 33.85 Calibration tests 33.87 Endurance test 33.88 Engine over temperature test 33.89 Operation test 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35.

AC 33-8 Appendix 2

8/19/09

Filter condition Could be affected Could be affected (Weight changes) mode Subpart F – Block Tests; Turbine Aircraft Engines 33.90 Initial maintenance inspection 33.91 Engine component tests 33.92 Rotor locking tests 33.93 Teardown inspection 33.94 Blade containment and rotor unbalance tests 33.95 Engine-propeller system tests 33.96 Engine tests in auxiliary power unit (APU) 33.97 Thrust reversers 33.99 General conduct of block tests Part 33 - Appendix A – Instructions for Continued Airworthiness Part 33 - Appendix B - Certification Standard Atmospheric Concentrations of Rain and Hail 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46.

AC 33-8 Appendix 2

AC 33-8 8/19/09 Appendix 3 APPENDIX 3. REVERSE ENGINEERING DESIGN PROCESS Reverse engineering requires comprehensive comparative tests and analyses to show the proposed PMA part complies with the applicable requirements of part 33 or the standard defined by TSO C77. An outline of a reverse engineering design process for complex parts is provided below with details at each step. While not all proposed PMA parts require all of these steps, the more complex parts will generally use most of them.

1. Research and Background Processes.

a. Visual and dimensional inspection of sample parts (new).

b. Service history review (for example, service bulletins, service difficulty reports (SDRs) and Airworthiness Directives (ADs)).

c. Review of field returned parts (for example, for wear, cracking and erosion).

d. Define interfaces (such as datum structure and fits and clearances).

e. Patent review (consider unique, novel, or subtle design features not detected through the typical reverse engineering process).

f. ICA review (such as cleaning, inspection, key features, repairs and fits and clearances).

g. Similar part drawing review (PMA holder or public domain).

h. Public domain material specification (such as Aerospace Material Specifications and Mil Handbooks).

i. International standards for drawings (such as the American Society of Mechanical Engineers).

j. Standard part drawings (such as gears, fasteners and bearings).

k. Manufacturing technology and sources available to produce the part.

l. Discrepancy review versus available data (outside serviceable limits).

m. Quality evaluation report (quality differences related to the type design suppliers).

2. Technical Data Generation Processes: a. Dimensions and tolerances (part and mating parts as required).

b. Interface definition.

AC 33-8 8/19/09 Appendix 3 c. Surface finish.

d. Break edges and chamfers.

e. Stack-up Analysis.

f. Hidden features (those features lost during assembly or processing of the detail parts).

g. Materials. These include: • Micro and macrostructure; • Coatings; • Plating; • Material forms (such as bar stock, forging and casting); and • Material chemistry including trace element requirements.

h. Performance specifications (such as loads, fatigue life and duty cycle).

i. Testing specifications (acceptance tests, functional tests).

j. Non-destructive testing requirements (such as fluorescent penetrant inspection and ultrasonic).

k. Surface enhancements (such as shot peening).

l. Non-conventional machining assessment (such as EDM, laser drilling and chemical milling).

m. Quality requirements (creation of the preliminary inspection plan).

n. Manufacturing process control requirements (substantiated and controlled processes such as material melt practices, plating, heat treat, welding and brazing).

3. Design Verification Processes: a. Final independent design review.

b. Conformity inspection of prototypes.

c. Testing (functional, operational, and system tests).

d. Inspection and quality assurance requirements.

e. Complete technical data package with test results.

f. Dimensional comparison of prototype with drawing and type design part.

AC 33-8 8/19/09 Appendix 3 g. Visual comparison or prototype with type design part.

h. Fit-check comparison with type design part.

i. Weight comparison with type design parts.

j. Part marking review.

4. Project Implementation including : • Define procurement requirements (for example, special quality clauses); • Supplier selection and approval; and • Delivery of first articles and conformity inspections.

AC 33-8 8/19/09 Appendix 4 APPENDIX 4. CONTINUED OPERATIONAL SAFETY 1. Continued Operational Safety is a closed-loop technical and logistical support system that ensures the continued safety of a part and subsequently the product on which it is installed, throughout its lifetime. This support system includes three fundamental elements: • Prevention; • Data collection and monitoring; and • Response and resolution.

2. The closed-loop system and the relationship between the three fundamental elements are shown in figure A4.1 below: Figure A4.1: Fundamental Elements of Continued Operational Safety Prevention Design, Certification & Manufacturing Lessons Learned Feedback Loop Data Collection Service Reliability, and Trending, Usage & Monitoring Part Failures Investigation, Response and Analysis, Risk Mitigation, Resolution Corrective Action 3. The prevention element is intended to preclude in-service problems before they have a chance to occur. The prevention element includes those activities and processes that are applied during the part design, certification, and manufacturing stage to ensure the design is adequate; the certification is thorough; and the manufacturing is controlled. PMA applicants establishing a COS plan should include procedures that address the following: a. Internal Audits . Internal audits are used to monitor compliance with required airworthiness standards and procedures to ensure production of airworthy components. The audit must include detailed reviews of all Aircraft Certification Systems Evaluation Program (ACSEP) and Principal Inspector (PI) audit results and any reports made to satisfy § 21.3. The auditing procedures should have a feedback reporting system to ensure that proper and timely

AC 33-8 8/19/09 Appendix 4 corrective action is taken in response to reports resulting from the independent audits. Another organization or person with appropriate technical knowledge and experience is often used to conduct the audit.

b. Part Field Experience . The following sources are available to evaluate part field experience: • Service difficulty reports (SDRs) (located at: http://av-info.faa.gov/sdrx / ); • Pertinent airworthiness directives (ADs); and • Available ICA (including overhaul instructions, illustrated parts catalogs, and service bulletins (SB)) should also be reviewed.

(1) Operators and maintenance providers may also have service experience with the part, next higher assembly, or both. Surveying these operators and maintenance providers may be useful to confirm the findings of any SDR, Alert SB, SB, or AD review.

c. Design Review and Safety Analysis Process . The safety analysis process is a systematic review of a design at appropriate stages. The process can identify any potential failure, malfunction, or defect and considers the impact on the part, the next higher assembly, interface features, airworthiness characteristics, manufacturing controls, and inspection plans.

This information can be used to establish preventative action. The process also evaluates the effectiveness of the preventative action through follow-on reviews. Participants in these reviews should include representatives of functions concerned with the design under review. Records of review and subsequent actions must be maintained and should include: • A review of the available ICA and service history evaluation; and • A safety assessment of the PMA part.

d. Part Development Planning Process . For critical and complex parts, the process focuses on structuring the design effort into significant elements to ensure part safety and reliability. The elements include: (1) A design and development plan; (2) A review, verification, and validation process appropriate to each design and development stage; (3) The responsibilities and authorities for design and development; (4) A means to record project communication; and (5) Recording of design and development inputs related to part requirements (inputs should include functional and performance aspects, statutory and regulatory requirements, and information gathered from similar designs).

AC 33-8 8/19/09 Appendix 4 e. Manufacturing Process Change Control and Substantiation . To ensure part safety and reliability, applicants utilizing a COS plan should consider a system to control manufacturing processes. Such a system requires that each process be performed by qualified personnel in accordance with approved specifications containing definitive quality standards. Certain parts may need engineering source approval (controlled or frozen manufacturing processes) of changes to the manufacturing process or inspection system, or both. Substantiation for a proposed process change may include functional or destructive testing, or both.

4. The data collection and monitoring element includes those activities and processes focused on the collection, assimilation, and interpretation of data related to in-service part performance, for example, reliability, trending and usage. It consists of the following procedures: a. Closed Loop Process for all Field Inquiries . This process is used to review, evaluate, and respond to inquiries or notifications of potential service problems from aircraft operators, maintenance service providers, or the FAA. This process includes a list of individuals or organizations within the company with defined responsibilities for responding to all inquiries and notifications. The process is used to identify appropriate methods and resources to investigate service problems, identify the cause of any service difficulties, develop corrective actions, and implement those actions in a timely manner. The process is also used to define how the resolution and corrective action would be transmitted to the reporting entity, other entities potentially impacted, and the FAA.

b. Part-Specific Performance Data Trend Analysis . The data trend analysis process is based on part-specific performance. This process is for a PMA part that is determined during the design phase to have a potential adverse effect on the operational safety of the product if it does not perform as intended. This process should include a means for the PMA holder to track its parts, and receive inspection and qualitative feedback from the part user after the part is removed from service for any reason, including routine maintenance. When possible, input from the product operator regarding part performance relative to the design assumptions should be sought.

c. Part Delivery Statistics . This process records the quantity of parts shipped, the shipping date and customer. The records should also contain sufficient information to accurately link each shipped part to its lot number or to a manufacturing order.

d. Continuing ICA Review . Continuing ICA review is a procedure to review all available new and revised TC holder’s maintenance instructions and service bulletins, as well as ADs that pertain to each TC holder’s part replaced by a PMA part. This procedure may use periodic searches of new or revised TC holder ICAs for referencing a TC holder part number replaced by a PMA part number. This procedure should include a list of qualified individuals or organizations within the company that can determine if any new or revised ICA could potentially affect the performance of their PMA part. The procedure should define the steps needed when it is determined the PMA part is affected by new or revised ICA.

5. The COS plan response and resolution element must include those activities and processes that focus on investigating and analyzing part failures, both actual and precursor; assessing the risks associated with continued operation; identifying and implementing any actions necessary

AC 33-8 8/19/09 Appendix 4 to mitigate an unsafe condition; and implementing corrective actions necessary to restore part safety. These activities and processes are: a. Reporting required under § 21.3 . Applicants already have this requirement within their FAA-approved fabrication inspection system. AC 21-9A, “Manufacturers Reporting Failures, Malfunctions, or Defects,” and AC 21-1B, “Production Certificates” provide further guidance for reporting under § 21.3.

b. Customer Notification Process. This process should include a procedure for the release and control of technical information issued to ensure all necessary parties are aware of a field problem. The notification system may include FAA review. The notification system should include detailed technical instructions for the end user to complete the necessary corrective action.

c. Ability to Identify, Develop, and Implement Field Corrective Action Plans . This activity should direct the development and implementation of corrective action plans to address unsafe conditions associated with the part failure. This activity should include a process to communicate with the supply chain and customers so that issues can be tracked and corrective actions implemented. A good reference for this process is AC 39-8, “Continued Airworthiness Assessments of Powerplant and Auxiliary Power Unit Installations of Transport Category Airplanes.” d. Failure Analysis Capability . The PMA holder should be capable of providing a failure analysis of any in-service or manufacturing difficulty. Failure analysis capability demonstrates the applicant understands the part, its interaction with mating parts, its manufacturing processes, and the product and engine. The company should have a policy that demonstrates its understanding of who should complete the failure analysis and how it is disseminated and presented to the FAA, if required.

e. Customer Support . The applicant should have the ability to source and manufacture replacement parts to ensure that reliability and safety issues are satisfactorily managed.

f. Feedback into Preventative Systems and Procedures . The final step in resolving service difficulties pertains to the lessons learned. We recommend applicants establish feedback to the existing engineering, quality, manufacturing, and safety systems. The objective of feedback is to prevent recurrence of these and similar problems, and, at a minimum, resolve them before an unsafe condition occurs. Feedback can occur through means such as a lessons learned library, training activities, continuous monitoring, and refinement of company processes. The applicant’s management, engineering, manufacturing, and quality departments should be aware of service information that requires changes regardless of the level of safety impacted. The key is to develop, implement, and monitor solutions to resolve problems and prevent future ones from occurring.