PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL

4. Loctite 222 (Screwlock) 2 5. Loctite 242 (Nutlock) 2 6. Loctite 271 (Studlock) 3 7. Loctite RC 680 4 Jan.16/12 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 4 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-TOC CHAPTER SECTION SUBJECT SUBJECT PAGE EFFECTIVITY FASTENERS - General 51-40-00 1 1. General 1 2. Types of Fasteners 1 3. Identification 1 4. Fastener Hole Preparation 6 FASTENERS - Installation 51-41-00 1 1. General 1 2. Solid Rivets 1 3. Cherrymax Rivets 8 4. Hi-Lok/Hi-Lite Pins 8 FASTENERS - Removal 51-43-00 1 1. Solid Rivets 1 2. Cherrymax Rivets 1 3. Hi-Lok/Hi-Lite Pins 4 SUPPORT OF AIRPLANE FOR REPAIR AND ALIGNMENT CHECK PROCEDURE - General 51-50-00 1 1. General 1 2. Description 1 AIRPLANE SUPPORT FOR REPAIR AND ALIGNMENT CHECK - Maintenance Practices 51-50-00 201 1. Airplane Simmetry Check - Procedure 201 CONTROL SURFACE BALANCING - General 51-60-00 1 1. General 1 CONTROL SURFACE BALANCING - Ailerons 51-61-00 1 1. Ailerons - Mass Balancing 1 Jan.16/12 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 5 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-TOC CHAPTER SECTION SUBJECT SUBJECT PAGE EFFECTIVITY CONTROL SURFACE BALANCING - Rudder 51-62-00 1 1. Rudder - Mass Balancing 1 CONTROL SURFACE BALANCING - Elevators 51-63-00 1 1. Elevators - Mass Balancing 1 REPAIRS - General 51-70-00 1 1. General 1 2. Standard Repair Data 1 ELECTRICAL BONDING OF STRUCTURE - General 51-80-00 1 1. Bonding Surface Preparation 1 2. Surface Finish 1 NON-DESTRUCTIVE TESTING - General 51-90-00 1 1. General 1 2. Coin Tapping 1 3. Dye Penetrant 1 4. Eddy Current 2 5. Ultrasonic 2 6. Magnetic Particle 3 7. Radiographic 3 Jan.16/12 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 6 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-TOC INTENTIONALLY LEFT BLANK Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 1 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-00-00 STRUCTURE - GENERAL 51-00-00 1. General (Ref. Fig. 1) A. The airplane structure is manufactured from metal and composite materials. The locations of the metal and composite parts are shown in Fig. 1. This topic gives a general description of the construction and materials of the major sections of the structure. B. For the dimensions and areas of the airplane structure refer to Chapter 06-00-00. C. For information about access panels and doors refer to Chapter 06-00-00. 2. General Description A. Nose Section The nose section comprises the forward avionics compartment, forward wing and nose landing gear bay. The avionics compartment comprises a metal equipment platform covered by a fiberglass honeycomb radome/metal nosecone. The equipment platform is supported by the keelbeams and the forward pressure bulkhead. The forward wing is metal-made and is attached to four machined fittings mounted on the keel beams. The forward wing is equipped with metal bonded trailing edge flaps. The nose landing gear is suspended from the structure below the flight compartment floor and retracts forwards into a non-pressurized bay. The nose landing gear bay is enclosed by composite doors. An all metal landing/taxi light panel is located forward of the nose landing gear bay. B. Fuselage The fuselage comprises the flight compartment, passenger compartment and baggage compartment. The fuselage is of semi-monocoque construction manufactured, in two sections, from 2024 Alclad aluminium alloy. The fuselage is joined at the rear pressure bulkhead which separates the pressurized flight and passenger compartment from the unpressurized baggage compartment. All the compartment floors are constructed of aluminium alloy sheet supported by floor beams. C. Wing/Fuselage Intersection The wing fuselage intersection is the area to the rear of the rear pressure bulkhead where the wing spars connect to the fuselage bulkheads. The area above the wing between the center bulkhead and rear pressure bulkhead forms the fuselage integral tank. The main landing gear is attached to milled aluminium plates bolted between the center bulkhead and the rear pressure bulkhead. An aluminium alloy structural panel is located between the lower surface of the wing and the landing gear mounting plate. The main landing gear retracts rearwards into unpressurized bays enclosed by composite doors. D. Empennage The empennage comprises the tailcone, ventral fins, vertical stabilizer and rudder, and horizontal stabilizer and elevators. The tailcone is metal-made except the rear end part that is in fiberglass. The three bulkheads are strengthened along their vertical centerlines to provide support for attaching the vertical stabilizer spars. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 2 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-00-00 The bulkheads also provide support for all composite ventral fins. The vertical stabilizer and the rudder are metal-made. The horizontal stabilizer is a composite structure connected to a hinge mounted at the rear of the vertical stabilizer. The forward part of the horizontal stabilizer is connected to an actuator mounted inside the vertical stabilizer. The elevators are metal-bonded structures constructed from aluminum honeycomb. E. Main Wing The main wing is constructed in two halves, left and right, which are permanently joined together inside the fuselage, aft of the rear pressure bulkhead. The main wing upper and lower skins are manufactured from aluminium alloy machined with integral stiffeners in a grid pattern. The forward and aft spars are machined aluminium alloy with integral webs to correspond with the rib stations. The aluminium ribs are rivetted or bolted between the spar webs and the chordwise stiffeners of the skin panels. The complete assembly forms a torsion box which carries all the wing bending, shear and torque loads. Each torsion box is sealed to form the left and right wing tanks. The front and rear spars have machined titanium fittings for installation of the engine mounting frame. A third spar is installed between the nacelle and the fuselage centerline to improve stiffness in the wing root area. Each wing has two aluminium alloy leading edges, one inboard of the nacelle and one outboard of the nacelle. Both leading edges are removeable. Each wing has an aluminium alloy outer trailing edge and a composite center trailing edge. The main wing outboard fowler flaps are metal structures. Each flap is mounted on roller supports which travel in tracks attached to the wing torsion box. The inboard single slotted flaps are metal-bonded, manufactured from aluminium honeycomb with thin aluminium skins. The ailerons are metal-bonded, manufactured from aluminium honeycomb. The right aileron has a trim tab attached with a piano hinge. F. Engine mounting frame and nacelles The engine mounting frame is a titanium structure, divided into two subassemblies by a machined stainless-steel fireproof bulkhead. The nacelles are composite structures manufactured in four parts and attached to wing mounting strips and a splice bulkhead on the engine mounting frame. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 3 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-00-00 Fig. 1 (Sheet 1 of 2) - Structure - Identification Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 4 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-00-00 Fig. 2 (Sheet 2 of 2) - Structure - Identification Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 1 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 STRUCTURE - CLASSIFICATION 51-01-00 1. General A. To assist operators in the determination of the strength standards required for repairs and the urgency with which they must be done, the main structural components are classified to indicate their relative importance. The structural classification of a component must be considered when assessing damage (Refer to 51-11-00). B. The classification is given by shading on the illustration pages (Refer to Fig. 1) and on the following table. Definitions of the structural classification are as follows: (1) Primary – That structure which provides major loads paths for balance of the loads applied to the airplane, or provides essential support necessary to maintain safe operation of the airplane. (2) Secondary – That structure which transmits loads paths from their point of application to the primary structure. Secondary structure may be highly stressed parts that do not act as primary structure. (3) Tertiary – That structure which does not contribute to the structural strength of the airplane. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 2 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 STRUCTURE CLASSIFICATION ITEM STRUCTURE PRIMARY SECONDARY TERTIARY 1 EMERGENCY DOOR • 2 FORWARD FUSELAGE • 3 CABIN DOOR • 4 FORWARD WING FLAP • 5 FORWARD WING FLAP • 6 FORWARD WING TIP • 7 FORWARD WING • 8 FORWARD WING TIP • 9 FORWARD WING FAIRING • 10 FRONT PRESSURE BULKHEAD • 11 NLG REAR DOOR • 12 NLG LEFT DOOR • 13 LANDING/TAXI LAMPS ASSY • 14 NLG RIGHT DOOR • 15 FORWARD WING FAIRING • 16 RADOME/NOSE CONE • 17 MAIN WING TIP • 18 AILERON • 19 FLAP TRACK COVER • 20 CENTRAL TRAILING EDGE • 21 OUTBOARD FLAP • 22 FLAP TRACK COVER • 23 INBOARD FLAP • 24 REAR FUSELAGE • 25 NACELLE • 26 BAGGAGE COMP. DOOR • 27 INBOARD FLAP • 28 NACELLE • 29 ENGINE MOUNT • 30 FLAP TRACK COVER • 31 CENTRAL TRAILING EDGE • 32 OUTBOARD FLAP • 33 FLAP TRACK COVER • 34 AILERON • Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 3 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 35 MAIN WING • 36 MAIN WING TIP • 37 LEADING EDGE OUTBOARD • 38 FAIRING • 39 LEADING EDGE INBOARD • 40 MLG REAR DOOR • 41 MLG FWD DOOR • 42 MLG REAR DOOR • 43 MLG FWD DOOR • 44 REAR PRESSURE, BULKHEAD • 45 LEADING EDGE INBOARD • 46 FAIRING • 47 ENGINE MOUNT • 48 LEADING EDGE OUTBOARD • 49 MAIN WING • 50 FAIRING • 51 HORIZONTAL STABILIZER • 52 ELEVATOR • 53 ELEVATOR • 54 RUDDER • 55 RUDDER TRIM • 56 VERTICAL FIN/TAIL CONE • 57 TAILCONE FAIRING • 58 VENTRAL FIN • 59 FIN LOWER LEADING EDGE • 60 VENTRAL FIN • 61 FLOOR PANELS (ALL) • 62 FLOOR BEAMS (ALL) • 63 INTEGRAL FUEL TANK • STRUCTURE CLASSIFICATION ITEM STRUCTURE PRIMARY SECONDARY TERTIARY Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 4 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 Fig. 1 (Sheet 1) - Structural Classification Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 5 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 Fig. 2 (Sheet 2) - Structural Classification Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 6 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 Fig. 3 (Sheet 3) - Structural Classification Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 7 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 Fig. 4 (Sheet 4) - Structural Classification Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 8 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-01-00 INTENTIONALLY LEFT BLANK Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 1 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-03-00 STRUCTURE - DIMENSIONS AND AREAS 51-03-00 1. General A. For the dimension and areas of the airplane Structure refer to Chapter 06-00-00. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 2 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-03-00 INTENTIONALLY LEFT BLANK Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 1 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-05-00 STRUCTURE - ACCESS PANELS AND DOORS 51-05-00 1. General A. For information about access panels and doors refer to Chapter 06-00-00. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 2 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-05-00 INTENTIONALLY LEFT BLANK Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 1 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-10-00 DAMAGE - GENERAL 51-10-00 1. General A. This topic gives the procedure for assessing damage and selecting a suitable repair scheme. The procedure includes: – Examination of structure – Assessment of damage – Secondary damage – Protection of adjacent equipment – Access for repair – Application of repair schemes. 2. Examination of Structure A. A detailed examination of the structure must be made before assessing damage. The following procedure is given as a general guide. (1) Examine the structure for: – Cracks and buckling – Scores and scratches – Drawn rivet and bolt holes. (2) Examine castings and machined parts for cracks, if necessary use a non destructive test method (Refer to 51-90-00). (3) Check rivets for security. Use a thin feeler gage to locate gaps under rivet heads or between rivetted plates. Cracked or flaking paint is usually a sign of rivet disturbance. (4) Check all systems and controls near the damage for: – Fractured or distorted pipes – Frayed or kinked control cables. (5) Examine the structure for distortion using a straight edge, clinometer, trammels or other suitable equipment. NOTE: Keep an accurate record of each defect found to make sure no damage is missed during subsequent repair operations. (6) Support the structure (Refer to 51-50-00). 3. Assessment of Damage A. Locate and identify the area of damage and establish the structural classification (Refer to 51-01-00). Where damage exists in more than one classification area, the highest classification applies. B. Locate and identify the damaged components and assess the allowable damage limitations (Refer to 51-11-00). If the damage is within limits a suitable repair scheme can be implemented, but consideration should be given to the economic viability of repair or replacement of the components. If the damage is outside the limits the components must be replaced. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 2 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-10-00 4. Secondary Damage A. Any damage to the airplane, particularly when shock is sustained, is likely to produce secondary damage. A close examination of the structure surrounding the primary damage must be made to find any secondary damage. B. Secondary damage is caused by the transmission of force and may be located some distance away from the primary damage. The transmission of force can result in structural deformation and drawn rivet and bolt holes. Secondary damage can also occur due to fatigue following weakening of the structure. 5. Protection of Adjacent Equipment A. All adjacent equipment must be adequately protected or removed to avoid damage during repair operations. B. For the removal and installation procedures for equipment refer to the appropriate chapter of the maintenance manual. 6. Access for Repair A. It may be necessary to gain access to a structural member by releasing or removing an area of skin. B. When an area of skin is released, care must be taken to avoid buckling or kinking of the skin as it is peeled back. When the skin is attached, the fasteners must be the same type as originally installed. If the fasteners holes are enlarged during the drilling out of the original fasteners, oversized fasteners must be used to attach the skin (Refer to 51-41-00). 7. Application of Repair Schemes A. Where damage is considered repairable, refer to 51-70-00 for a suitable Repair Scheme, or to the Standard Repairs topic in the appropriate chapter of the maintenance manual. B. For information about materials used for the local manufacture of parts refer to 51- 31-00. C. On completion of the repair, restore the surface treatment in accordance with 51- 23-00, and the surface finish in accordance with 51-25-00. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 1 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 DAMAGE - CLASSIFICATION 51-11-00 1. Allowable Damage A. General (1) Allowable damage is defined as minor structural damage to secondary and tertiary structure that is permitted to exist as it is or which may be corrected by a simple procedure, such as stop drilling cracks or smoothing out nicks. The damage is not considered to be critical in affecting flight safety or reducing the performance of the aircraft below minimum safety standards. Damage to primary structure must be referred to the manufacturer. (2) No repairs is allowed that may cause permanent deformation, aerodynamic mismatch or affect function and fit of structural elements. (3) No repair is allowed if it may cause fuel leakage. (4) No repair is allowed that causes a reduction in net area of more than 20%, including original holes and cutouts. (5) The maximum number of allowable damages is not to exceed two within 10 inches of a structural member. (6) All limitations of the extent of damage refers to dimensions after clean up. NOTE: All cracks must be repaired; immediately if they exceed the limits herein, otherwise within 150 hours. 2. Allowable Cracks Metallic Structure A. Type I, Edge of a Plate (Figure 1) (1) Limitations (a) Thickness less than 0.125 inches. (b) Y/D greater than or equal to 1.5 inches. (c) X/H less than or equal to 0.05 inches. (d) Maximum length X = 0.25 inches. (e) Maximum of one crack at cross section. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 2 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 B. Type II, Edge of a Rivet Hole (Figure 2) (1) Limitations (a) X1, X2, less than 0.015 inches. (b) @ greater than or equal to 1.5 inches X diameter of reamed up hole. (c) Y greater than or equal to 3.0 inches X diameter of reamed up hole. (d) Maximum of one crack at cross section. C. Type III, Edge of a Lightening Hole (Figure 3) (1) Limitations (a) X less than or equal to 0.050 inches. (b) X/D less than or equal to 0.050 inches. (c) Maximum of one crack at a hole. Fig. 1 - Type I, Edge of a Plate Allowable Damages Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 3 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 Fig. 2 - Type II, Edge of a Rivet Hole Allowable Damage Fig. 3 - Type III, Edge of a Lightening Hole Allowable Damage Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 4 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 3. Allowable Gouges and Nicks Metallic Structure A. Type I, Skin, Webs and Leading Edges (Figures 4 and 5) (1) Limitations (a) L/H less than 0.5 inches. (b) X/t less than 0.05 inches. (c) Y greater than L1, L2 whichever is larger. (d) Z greater than 20X. (e) Maximum 2 gouges per cross section. (f) Maximum length 3 inches. B. Type II, Skin, Webs and Leading Edges (Figures 4 and 5) (1) Limitations (a) L/H less than 0.5 inches. (b) X/t less than 0.10 inches. (c) Y greater than L1, L2 whichever is larger. (d) Z greater than 20X. (e) Maximum 2 gouges per cross section. (f) Maximum length 3 inches. C. Type III, Skin, Webs and Leading Edges (Figures 4 and 5) (1) Limitations (a) L/H less than or equal to 0.10 inches. (b) X/t less than or equal to 0.2 inches. (c) z/D = 20X. (d) Maximum one gouge per cross section. (e) Maximum length 1.5 inches. D. Type IV, Skin, Webs and Leading Edges (Figures 4 and 5) (1) Limitations (a) L/H less than or equal to 0.10 inches. (b) 0.2 less than or equal to x/t less than 0.5 inches. (c) L/E less than 2. (d) L/Z less than 2. (e) Maximum one gouge per cross section. (f) Y greater than 5L1, 5L2 whichever is larger. (g) Maximum length 1.0 inches. Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 5 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 Fig. 4 - Type I, II, III and IV, Skin and Webs Allowable Damage Fig. 5 - Type I, II, III and IV Skin and Leading Edge Allowable Damage Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 6 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 E. Type VI, Spar Caps and Stiffeners (Figure 6) (1) Limitations (a) L/H less than or equal to 0.10 inches. (b) X/t less than or equal to 0.10 inches. (c) Z greater than 20X. (d) Maximum one gouge or nick per cross section. (e) Y greater than 2L, 2L2, whichever is larger. (f) Maximum length 0.5 inches. F. Type VII, Small Deep Niks (Figure 7) (1) Limitations (a) t less than or equal to 0.125 inches. (b) y less than or equal to 0.250 inches. (c) x no limit (d) @/y greater than or equal to 2. (e) Maximum one nick per cross section. (f) Maximum diameter 0.25 inches. Fig. 6 - Type VI, Spar Caps and Stiffeners Allowable Damage Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 7 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 4. Allowable Dents Metallic Structure A. Type I, Dents (Figure 8) (1) Limitations (a) t less than or equal to 0.125 inches. (b) X less than or equal to 0.10 inches. (c) x/R less than 0.03 inches. Fig. 7 - Type VII, Small Deep Nicks Allowable Damage Fig. 8 - Type I, Dents Allowable Damage Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 8 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 5. Composite Material Allowable A. Type I, Dent at Edge Member (Figure 9) (1) Primary Structure (a) D = less than or equal to 0.30 inch. (b) e = greater than or equal to .25 inch. (c) x = less than or equal to 0.10 inch. (d) @ = less than or equal to 0.5 inch. NOTE: Up to 3 cracked layers. (2) Secondary Structure (a) D = less than or equal to 0.50 inch. (b) e = greater than or equal to .25 inch. (c) x = less than or equal to 0.20 inch. (d) @ = less than or equal to 1.0 inch. NOTE: Up to 6 cracked layers. Fig. 9 - Type I, Dent at Edge Member Allowable Damage Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 9 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 B. Type II, Dent at Mid section (Figure 10) (1) Primary Structure (a) D = less than or equal to 0.50 inch. (b) x = less than or equal to 0.10 inch. (c) @ = less than or equal to .75 inch. NOTE: One broken layer. (2) Secondary Structure (a) D = less than or equal to 0.75 inch. (b) x = less than or equal to 0.25 inch. (c) @ = less than or equal to 1.0 inch. NOTE: Two broken layers. Fig. 10 - Type II, Dent at Mid Section Allowable Damage Dec. 15/09 International AeroTech Academy For Training Purpose Only EFFECTIVITY: Page 10 PIAGGIO P.180 AVANTI II MAINTENANCE MANUAL 51-11-00 C. Type III, Delamination or Swelling (Figure 11) (1) Primary Structure (a) @ = less than or equal to 0.75 inch. (b) x = less than or equal to 0.05 inch. (c) @ = less than or equal to 1.5 inch. (d) x = less than or equal to 0.10 inch. Fig. 11 - Type III, delamination or Swelling Allowable Damage Dec. 15/09 International AeroTech Academy For Training Purpose Only