ROBINSON MAINTENANCE MANUAL MODEL R66

MAR 2025 Chapter 5 Inspections Page 5.1 ROBINSON MAINTENANCE MANUAL MODEL R66 FIGURE 5-2 ROD END CENTERING Position rod ends for maximum rotation FIGURE 5-1 ROD END AND SPHERICAL BEARING PLAY LIMITS AND TORQUE STRIPE APPLICATION Page 5.2 Chapter 5 Inspections MAR 2025 ROBINSON .----HOUSING MAINTENANCE MANUAL NOTE FOR MAXIMUM ROD EXTENSION WHEN NO WITNESS HOLES IS PROVIDED: ROD END A 101-4 D163-1 D173-1 9max 1.10 in. 1. 40 in . 1. 30 in . I MAXIMUM RADIAL PLAY 0 . 010 INCH TORQUE STRIPE * F101-4 1. 10 in . -----+---- A PIECE OF 0 .020 INCH DIAMETER SAFETY WIRE MUST NOT PASS THROUGH THE WITNESS HOLE MODEL R66 COMPONENT AN316 JAM NUT BALL BEARING - ( :$ ) · ~-+330 PALNUl------l--Q_/ _ ______....., li ffl , - -0-~- TORQUE STRIPE * L TORQUE STRIPE * BOLT SAFETY I WASHER MAXIMUM AXIAL PLAY 0.020 INCH * Typical torque stripe location shown . Adjust location as required for maximum visibility during preflight & 100-hr inspection. 1/ A 115-1 OR C115-1 SPACER (SMALL DIAMETER OF SPACER) TO CONT ACT ROD END BALL) EXPOSED THREADS PALNUT LF-LOCKING NUT WASHER 5-32 Push-Pull Tubes 1. Nicks, cuts, or scratches in tube not more than 0.010 inch deep and not more than 1/4 of tube circumference may be polished out in lengthwise direction using 320-grit or finer wet-or-dry abrasive paper to 1-inch minimum blend radius. Replace push-pull tube if depth exceeds these limits. 2. Replace push-pull tube if tube is dented or flattened more than 5% of its diameter in unswaged area; dents or flattening is not permitted in swaged (tapered and threaded) ends of tubes. 5-33 Rod Ends and Spherical Bearings 1. Maximum axial play: 0.020 inch (for A104-4 bearing only: 0.035 inch axial play) Maximum radial play: 0.010 inch 2. Looseness between spherical bearing outer race & rod end housing, or between spherical bearing outer race & part, is not permitted. 3. Rod ends not riveted in place must block passage of 0.020-inch diameter wire through witness hole. Refer to Figure 5-1 for maximum rod end extension when no witness hole is provided. 4. Rod end jam nuts and palnuts must be torqued per § 20-32 and torque striped per Figure 5-1 at the most visible position for pre-flight inspection. Torque stripe must extend across nuts to both rod end shank and push-pull tube (or pitch link barrel, yoke, support, strut, etc.). Torque stripes are subject to deterioration and must be periodically renewed. 5. Refer to Figure 5-2. Rod ends must be positioned (centered) to allow as much push- pull tube or link rotational movement as possible without binding. CAUTION Teflon-lined bearings must not be lubricated or solvent cleaned. WARNING Assembly of flight controls is critical and requires inspection by a qualified person. If a second person is not available, RHC recommends the installer take a 5-minute break prior to inspecting flight control connections the installer has assembled. JUL 2023 Chapter 5 Inspections Page 5.3 ROBINSON MAINTENANCE MANUAL MODEL R66 Elastomer Fatigue Elastomer Overload FIGURE 5-3 ELASTOMERIC BEARING DAMAGE Page 5.4 Chapter 5 Inspections JUL 2023 Elastomer Oil Contamination ROBINSON MAINTENANCE MANUAL MODEL R66 \j \\ • ~ ' \ \~ 11~\ //~ I MAY 2021 Chapter 5 Inspections Page 5.5 5-34 Elastomeric Bearings Refer to Figure 5-3. Elastomeric bearings are used in the G062-1 tail rotor hub assembly. Fatigue, oil contamination, or overload can degrade the elastomer. Small surface cracks (fatigue cracks) and elastomer dust or “eraser crumbs” are normal and are not cause for replacement. As cracks grow, enough elastomer will be lost to cause reduced stiffness and increased vibration. Replace bearing if crack is deeper than 0.10 inch or cracks are present over more than 25% of elastomer face. Avoid elastomer exposure to oil, grease, hydraulic fluid, cleaning solvent, and rust- preventative fluids. Immediately wash off contaminants with detergent and water. Replace a contaminated bearing that exhibits swelling, wavy edges, or debonding. Overload occurs when elastomer’s tensile strength or rubber-to-metal bond strength is exceeded. This can occur when normal loads are applied to a bearing weakened by fatigue or oil contamination. Overload is indicated by large clean cracks or extrusions from elastomer. Elastomer may also separate (debond) from metal bushings. Replace bearing if separation exceeds 25% of bonded area. ROBINSON MAINTENANCE MANUAL MODEL R66 5-35 Telatemp Indicators Refer to Figure 5-4. Self-adhesive Telatemp indicators record increases in operating temperatures of the hydraulic pump and tail rotor gearbox. To use a Telatemp, draw a reference line between the highest temperature square which has darkened during normal operation and the next undarkened square. During every check thereafter, determine if an additional square has blackened. If an indicated temperature increase cannot be accounted for by a change in operating conditions, carefully examine the component before further flight. NOTE Telatemps can indicate erroneously if contaminated by a petroleum product, typically appearing as white, unactivated square(s) between darkened squares at each end; replace any Telatemp indicating as such and clean area with acetone prior to installing. Part Number Temperature Range F110-2 60°C / 140°F — 88°C / 190°F F110-3 82°C / 180°F — 110°C / 230°F F110-4 104°C / 220°F — 132°C / 270°F FIGURE 5-4 TELATEMP INDICATOR WITH DRAWN REFERENCE LINE Page 5.6 Chapter 5 Inspections MAY 2021 ROBINSON MAINTENANCE MANUAL MODEL R66 telatemp TEMPERATURE RECORDER aci ii □ □ □Of220 230 240 250 260 MODEL 110-4 ' FULLERTON, CA -"' 714-879-2901 132°c □270°F Reference line 5-36 Torque Stripes If, during inspection, the remaining torque stripe on a fastener is insufficient to determine joint integrity, then remove accompanying palnut as required and apply specified torque to fastener. If fastener moves, disassemble joint and inspect parts for damage such as fretting, thread deformation, hole elongation, etc.; replace damaged parts. If fastener does not move, install new palnut as required & standard torque per § 20-32. Torque stripe fastener per § 20-31. JUL 2020 Chapter 5 Inspections Page 5.7 ROBINSON MAINTENANCE MANUAL MODEL R66 5-40 Operation Checks for 100-Hour / Annual Inspection Complete the following checklists in conjunction with 100-hour / annual inspection. Note and correct any discrepancies. 5-41 Ground Check (aircraft not running) 1. Twist Grip: Verify twist grip smooth rotation without binding in full up and full down collective position. Verify over center spring holds twist grip full open or closed. 2. Fuel Cutoff Valve: Verify smooth actuation without binding. Verify proper function of lock button. 3. Collective Control: Verify proper operation through full control travel with and without friction applied. With friction off, verify approximately one-half inch total free play before encountering hydraulic resistance. Verify normal hydraulic resistance throughout remainder of control travel. With friction on, verify increased resistance but no binding or locking of control. Verify power turbine governor rigging as follows: a. Turn battery switch on. With collective full down, hold beep switch actuator all the way down. Have a second person verify the PTG reads approximately 45°. b. With collective full down, hold beep switch actuator all the way up. Have a second person verify the PTG reads approximately 65°. Return actuator to nominal position. Turn battery switch off. 4. Cyclic Control: With friction off, verify approximately one-half inch total longitudinal and one inch total lateral free play before encountering hydraulic resistance. Verify normal hydraulic resistance throughout remainder of control travel. With friction on, verify increased resistance but no binding or locking of control. 5. Tail Rotor Pedals: Verify smooth actuation without binding. Verify proper pedal position for pilot and locking pin security. 6. Removable Controls (if installed): Verify proper operation and locking pin security. Page 5.8 Chapter 5 Inspections JUL 2020 ROBINSON MAINTENANCE MANUAL MODEL R66 5-41 Ground Check (continued) 7. Lighting, Instruments, and Audio Alerts: (Turn battery switch on.) ANNUNCIATOR PANEL AND ROTOR BRAKE LIGHTS a. MR TEMP PRESS segment illuminates. b. ENGINE OIL segment illuminates. c. GEN segment illuminates. d. LOW RPM segment illuminates. e. HYD segment illuminates (if hydraulic switch is OFF; later helicopters). f. COWL DOOR segment illuminates when fuel filler cowl door or baggage door is not closed. On later helicopters, the COWL DOOR segment also illuminates when an engine cowl door is not closed. g. ROTOR BRAKE segment illuminates (if rotor brake is applied). h. All annunciator panel segments illuminate when test button is depressed (segments below have additional behaviors): i. LOW FUEL and <12 GAL FUEL segments take approximately two seconds before they illuminate due to a time delay in circuit. If LOW FUEL segment illuminates immediately after test button depress, a fault is indicated. ii. EMU segment will illuminate only when test button is depressed. EMU segment takes approximately 10 seconds to perform self-test after battery is switched ON before it will illuminate. INSPECTION LIGHTING a. Left side cowl door – verify LEDs illuminate main rotor gearbox and hydraulic reservoir sight gages when cowl door is open (battery switch on or off). EXTERIOR LIGHTING a. Position lights – check function. b. Anti-collision light – check function. c. Landing lights – check function. JUL 2020 Chapter 5 Inspections Page 5.9 ROBINSON MAINTENANCE MANUAL MODEL R66 5-41 Ground Check (continued) 7. Lighting, Instruments, and Audio Alerts (continued): (Turn battery switch on.) INTERIOR LIGHTING a. Panel lighting & dimmer control – check function (position lights must be illuminated to enable panel lighting and dimmer control). b. Map light – check function. c. Digital voltmeter – indicates approximately 24 volts. d. Oil temperature gage – slight needle deflection with engine cold. e. Fuel quantity gage – indication of fuel level. AUDIO ALERTS (Later helicopters; verify tone in headset) a. High rotor RPM: a high/low "warble" tone will sound when test button is depressed (five times per second). b. High engine torque/MGT: a beeping tone will sound when test button is depressed (four beeps per second for two seconds followed by 12 beeps per second). (Turn battery switch off.) 8. Aircraft Documents: (Additional documents may be required in countries other than the US.) a. Inspect condition and verify R66 MT699-1 laminated pilot's checklist is current revision. Check revision status online at: www.robinsonheli.com. b. Inspect condition and verify R66 Pilot’s Operating Handbook is current revision and contains correct Equipment List/Weight & Balance Data. Check revision status online at: www. robinsonheli.com. c. Verify airworthiness certificate onboard & matches helicopter S/N. d. Verify registration certificate onboard & matches helicopter S/N and all registration markings. Page 5.9A Chapter 5 Inspections JUL 2020 ROBINSON MAINTENANCE MANUAL MODEL R66 JUL 2020 Chapter 5 Inspections Page 5.9B 5-42 Run-Up 1. Clean engine gas path, if required, per RR300 Series Operation and Maintenance Manual (OMM). 2. Perform Pilot's Operating Handbook (POH) Section 4 “Preflight” checklist. 3. Perform POH Section 4 “Before Starting Engine” checklist. 4. Prior to start, verify rotor brake locks out starter. 5. Prior to start, review the Cautions and Notes in POH Section 4 “Starting Engine and Run-Up”. 6. Perform POH Section 4 “Starting Engine and Run-Up” checklist. 7. Once stabilized idle is reached, disconnect ground power and switch generator ON. Verify ammeter shows non-zero generator load and GEN light out. Verify aircraft voltmeter reads 28.0 to 29.0 volts and calibrated voltmeter indicates 28.2 to 28.8 volts. When complete, disconnect calibrated voltmeter. 8. Switch generator OFF. Verify GEN annunciator illuminates, voltmeter reading decreases but remains at or above 24 volts, and ammeter decreases to zero. 9. Switch battery and generator OFF. Verify dual tachometer continues to function, then switch battery and generator back ON. Ensure avionics master switch is OFF, and depress annunciator panel Test button. Both sides of dual tachometer should drop to off-scale low indication while button is depressed. 10. With avionics master switch OFF, verify generator continues to supply power with battery OFF (instruments continue to function, voltmeter reading remains steady), then switch battery back ON. 11. Switch avionics master ON, and turn on avionics. Once avionics are on, verify avionics master controls power to all avionics by switching OFF then back ON. 12. Perform annunciator panel test with avionics master ON. Verify all segments illuminate. Verify dual tachometer continues to function during test. 13. Open collective twist grip (throttle) to flight position and allow RPM to stabilize. Set N2 RPM to 100%. N2 and rotor tach needles must be within 1% of point-to-point. 14. Beep RPM full down and verify N2 RPM is 98% or lower. Attempt to beep RPM full up, but DO NOT exceed 105%. Verify N2 at full beep up is 102% to 104%. Beep N2 back to 100%. ROBINSON MAINTENANCE MANUAL MODEL R66 Page 5.10 Chapter 5 Inspections JUL 2020 5-42 Run-Up (continued) 15. Transmit on 118.0, 125.0, and 135.0 MHz. Verify no variation in dual tachometer readings during transmission. 16. Briefly operate the heater at 100% N2 to ensure system functions and is clear of debris. 17. Check engine anti-ice system. Green anti-ice indicator should illuminate accompanied by small MGT increase when anti-ice is switched ON. 18. Raise collective slightly, reduce N2 RPM slowly via twist grip. Verify low RPM horns and light activate at 95% to 94% and continue at all lower RPMs. 19. Perform engine N1 DECELERATION CHECK per Section 4 of the Pilot’s Operating Handbook. (With N2/R at 100% and N1 at 80%, N1 decel to 70% following rapid throttle closure should take at least 2 seconds.) 20. Check hydraulic system operation. Using cyclic-mounted hydraulics switch, turn hydraulics OFF and verify HYD light on (if equipped). Using small longitudinal cyclic inputs, there should be approximately one-half inch of freeplay before encountering stiffness and feedback. Turn hydraulics ON. Controls should be free with no feedback or uncommanded motion. Pull hydraulic circuit breaker, and verify that hydraulics remain on regardless of cyclic hydraulic switch position. Reset system to breaker in, hydraulics switch ON. 21. Air conditioning (if installed): Verify system blows cold air on both low and high settings. Verify no EMI/RFI with other instruments and systems. After a flight with air conditioning on, verify water drains from drain tube in ship’s belly (may be little or no water in very dry conditions). ROBINSON MAINTENANCE MANUAL MODEL R66 5-43 Flight Check 1. Hover: a. Verify normal gage indications. b. Verify controllability in left and right pedal turns. c. Verify hydraulic system zeros cyclic stick forces. d. Evaluate vibration levels; if unacceptable, measure imbalance and correct. 2. Level Flight: Conduct at typical cruise altitude (weather permitting) and maximum continuous torque. Loading to typical operating conditions or nominal weight and CG in middle of envelope will provide the most useful evaluation. a. Verify tail rotor pedal position when yaw string is centered. Right pedal 0.25 to 0.75 inch forward of left pedal. b. Verify tail rotor elastic trim cord zeros pedal forces (cord applies left pedal force). c. Verify hydraulic system zeros cyclic stick forces and collective is balanced with no feedback. d. Verify acceptable control forces (feedback) with hydraulics off. e. Evaluate vibration levels; if unacceptable, measure imbalance and correct. NOV 2023 Chapter 5 Inspections Page 5.11 ROBINSON MAINTENANCE MANUAL MODEL R66 5-43 Flight Check (continued) 3. Power Assurance Check: Refer to R66 Pilot's Operating Handbook (POH) Chapter 5 power assurance chart. Conduct at typical cruise altitude (weather permitting) and maximum continuous torque (83%). Turn heater, generator, and anti-ice switches OFF. Stabilize N2/R at 100% (beep as required) and record the following values: a. N1 b. % Torque (83% nominal) c. OAT d. MGT e. Pressure altitude f. Oil pressure g. Oil temperature h. Determine max allowable MGT from power assurance chart. i. Calculate margin. Margin = Max allowable MGT - Indicated MGT. 4. Shutdown: a. Perform POH “Shutdown Procedure” checklist. b. Verify rotor brake function and ROTOR BRAKE annunciator segment illuminates. Page 5.12 Chapter 5 Inspections NOV 2023 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Maintenance and Inspection RHC recommends retaining a copy of the most recently performed 100-hour / annual checklist with the aircraft’s maintenance records to meet the requirement of 14 CFR § 91.417 (b)(1). R66 Serial No.: Technician Name: Registration No.: Technician Certificate Number: Collective-Activated (Time In Service) Hourmeter Indication: Helicopter Total Time In Service: Operation Checks: Perform ground and flight checks per § 5-40. A. Preparation Cleaning (required by 14 CFR Part 43, Appendix D, paragraph (a)): Before cleaning, identify leak/debris type & source, and note if more investigation is required. Clean main and tail rotor blades, hubs, and airframe exterior with a mild soap (pH between 7 & 9) and water solution per Chapter 20. CAUTION Do not spray main rotor hub, tail rotor gearbox vent, hydraulic reservoir vent, swashplate area, or bearing seals with high- pressure water or solvent as water or solvent may cause corrosion or breakdown of lubricants. See RR300 Series Operation and Maintenance Manual (OMM) for engine cleaning instructions and precautions. Access and Inspection Panels: Refer to R66 Illustrated Parts Catalog Chapter 6 for access and inspection panel locations. Remove or open necessary panels, doors, covers, fairings, and cowlings in accordance with 14 CFR Part 43, Appendix D, paragraph (a). NOTE If radio antennas are installed on removed panels, disconnect antenna lead and corresponding ground wire. Pull respective radio circuit breaker and tag circuit breaker with “Antenna Removed.” CAUTION Instrument console removal (§ 95-50) is not required for scheduled inspections. Sufficient access for inspection is gained by removing the chin inspection panel, as well as removal of installed avionics, as required (refer to Chapter 97). MAR 2025 Chapter 5 Inspections Page 5.13 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) B. Inspection CABIN FORWARD FOOTWELLS Tail Rotor Pedal Bearing Blocks: Remove pedal bearing block covers as required. Examine accessible portion with inspection light and mirror. Inspect condition. Check for looseness or play in pedal bearings. Maximum allowable play is 0.080 inch axially and 0.030 inch radially. Verify bearing block security. Adjustable Tail Rotor Pedals: Inspect condition. Verify no cracks in welds. Verify locking pins engage holes to secure adjustable pedals. Verify proper operating clearance. Verify no evidence of contact between outboard portion of lateral (torque) tube of RH pedal and under-floor longitudinal stiffener. Verify smooth actuation. Co-Pilot Removable Tail Rotor Pedals: Inspect condition. Verify no cracks in welds. Verify locking pins engage holes to secure removable pedals. Verify proper operating clearance and smooth actuation. Cabin Heater Diffusers: Inspect condition. Verify marking legibility. Verify no significant nicks, scratches or dents, or cracks in welds. Verify security. Fire Extinguisher and Mount: Inspect condition. Inspect fire extinguisher per manufacturer’s instructions. Verify no loss of charge or obstructions in extinguisher nozzle. Verify security. Map Holders: Inspect condition. Verify no defects, tears, or material deterioration. Remove foreign objects and verify security. License Holder: Inspect condition. Verify no defects, cracks in plastic, or material deterioration. Verify security. Cabin Chin and Floor: Inspect condition. Verify equipment security. Retrieve and discard trapped debris. CONSOLE Console Assembly: Inspect condition. Verify no significant nicks, scratches or dents; verify no cracks, corrosion, or loose rivets in lower console assembly. Verify hinge security. HID Landing Lights: Inspect condition. Verify proper installation and security of wiring and equipment. Page 5.14 Chapter 5 Inspections MAR 2025 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) CONSOLE (continued) Flight & Engine Instruments: Inspect condition. Verify proper instrument markings per R66 POH Section 2. Verify proper installation and security of wiring and equipment. Post Lights: Inspect condition. Verify proper function and equipment security. Fuel Cutoff Control and Guard: Inspect condition. Verify cable and mounting bezel security. Verify proper adjustment and smooth operation of knob. Verify guard is attached to console. Radios and Radio Trays: Inspect condition. Verify no cracks or corrosion. Verify proper installation and security of wiring and equipment. Pitot & Static Lines: Inspect pitot and static lines for obstructions, cracking, chafing, pinching or kinking. Verify integrity of pitot and static line connections. Verify line security. Tail Rotor Pedal Bearing Block Supports: Examine accessible portion with inspection light and mirror. Inspect both vertical sheet metal supports inside lower console and verify no cracks. Pay particular attention to area near NAS6603-13 bolts. Replace any cracked support prior to flight. Tail Rotor Controls: Examine accessible portion with inspection light and mirror. Inspect tail rotor control components for obvious defects. Verify operating clearance. Cabin Heater Hose: Inspect condition. Verify no collapsed areas or chafing. Verify hose clamp and hose security. Copper Bus Bars: Inspect condition. Verify no corrosion or bends in bus bar. Verify bus bar security and isolation from surrounding structure. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Close & Secure: Verify foreign objects are removed. Verify equipment security and cleanliness of interior. Close console and verify security. MAY 2021 Chapter 5 Inspections Page 5.15 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) PILOT-SIDE CONSOLE (Optional equipment) Pilot Avionics Support Weldment: Inspect condition. Verify no significant nicks, scratches, or dents on console shell. Verify no cracks in welds. Verify weldment mounting security. CIRCUIT BREAKER PANEL CAUTION Ensure BATTERY switch is turned off while circuit breaker panel is open. Panel Cover: Inspect condition. Verify no damage to nutplates and rails in panel interior. Verify marking legibility. Fuses and Fuse Holders: Inspect condition. Verify security and no corrosion. Verify correct fuse installation. Circuit Breakers: Inspect condition. Check airworthiness directive applicability. Verify proper installation and security. Copper Bus Bars: Inspect condition. Verify no corrosion or bends in bus bars. Verify bus bar security and isolation from surrounding structure. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Close & Secure: Verify foreign objects are removed. Verify equipment security. Verify cleanliness of interior and of access cover. Close cover and verify security. UNDER LEFT FRONT SEAT Lithium-Ion Battery Circuit Back-Up Batteries (required with optional Lithium-ion main battery): Inspect condition. Verify presence and proper orientation of (2) 9V back-up batteries. Verify security of battery trays and G468-1 mount assembly. Verify legibility of silkscreen lettering on mount. Inspect wiring for obvious damage. Page 5.16 Chapter 5 Inspections MAY 2021 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) HORIZONTAL CONTROL TUNNEL (Front seats) Covers: Inspect condition. Verify marking legibility. Antenna Wiring & Connectors: Inspect condition. Verify no loose, chafed, frayed, or broken wires. Verify no damaged connectors. Verify neatness, proper routing and installation, and security. Cyclic Box Assembly: Inspect condition. Verify no nicks, scratches, dents, cracks, corrosion, or loose rivets. Verify no distortion or damage on cyclic stop sheet metal assembly. Verify security. Cyclic Stick Assembly: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no cracks in welds. If paint has worn thru to metal, touch-up with § 20-75 approved primer. Verify security, proper operating clearance, and smooth actuation. Verify security of removable co-pilot grip and locking pin. Cyclic Boot: Inspect condition. Verify proper locking function of boot snaps. Verify no defects, tears, or material deterioration. Verify security. Cyclic Friction Assembly: Inspect condition. Inspect link rod end bearings per § 5-33. Verify no excessive flaring at either end of friction spacer. Verify proper installation, security, and operation. Cyclic Pivot: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Inspect spherical bearings per § 5-33. Verify proper installation, security, and operating clearance. Cyclic Horizontal Torque Tube: Examine accessible portion with inspection light and mirror. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no cracks around reinforcement blocks on both ends of torque tube. Verify proper installation, security, and operating clearance. Horizontal Push-Pull Tubes: Examine accessible portion with inspection light and mirror. Inspect condition per § 5-32. Verify no nicks, scratches, chafing, dents, cracks, or corrosion. Inspect rod end bearings per § 5-33; verify rod ends are centered and palnut and jam nut are tight. Check witness holes for proper thread engagement. Verify proper installation, security, and operating clearance. JUL 2023 Chapter 5 Inspections Page 5.16A ROBINSON MAINTENANCE MANUAL MODEL R66 Page 5.16B Chapter 5 Inspections JUL 2023 5-45 100-Hour / Annual Inspection (continued) HORIZONTAL CONTROL TUNNEL (Front seats; continued) Collective Stick Assembly: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no cracks in welds. Verify proper installation, security, and operation of collective micro switches. Verify security, proper operating clearance, and smooth actuation of both flight and throttle controls. Verify over center spring holds twist grip full open or full closed. Verify placard legibility. Collective Stick Torque Tube: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Collective Boot: Inspect condition. Verify proper locking function of boot snaps. Verify ty-rap is properly installed (loosely securing boot around collective stick). Verify no defects, tears, or material deterioration. Verify security. Fuel Valve Knob and Guard: Inspect condition. Verify cable and mounting bezel security. Verify proper adjustment and smooth operation of valve. Verify guard is present. Collective Friction & Stop Assembly: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion in stop assembly. Verify no bending or binding of stop through full control travel, with and without friction applied. Measure collective friction per § 67-22. Verify proper installation and security of collective friction lever and stop assembly. HeliSAS Autopilot (if installed): Inspect condition of associated equipment. Inspect wiring condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. Co-Pilot Removable Collective Stick Assembly: Remove co-pilot collective stick assembly. Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no damage to spring pin and safety wire at coupling. Firmly grasp coupling and rotate twist grip in each direction with opposite hand. Verify no free play of coupling or spacer relative to torque tube. Install removable collective stick in helicopter and verify both locking pins engage holes to secure stick. Verify security, proper operating clearance, and smooth actuation of both flight and throttle controls. Verify placard legibility. Co-Pilot Removable Collective Boot: Inspect condition. Verify proper locking function of boot snaps. Verify ty-rap is properly installed (loosely securing boot around collective stick). Verify no defects, tears, or material deterioration. Verify security. ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) HORIZONTAL CONTROL TUNNEL (Front seats; continued) Pitot & Static Lines & Drains: Inspect pitot and static lines for obstructions, cracking, chafing, pinching, or kinking. Remove drain plugs from tee fittings in each line and clear any moisture from system. Install drain plugs. Verify integrity of pitot and static line connections. Verify line security. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Antennas: Inspect condition. Verify no cracks where antennas mount to cowling. Verify security. Close & Secure: Verify foreign objects are removed. Verify equipment security. Verify cleanliness of interior and of inspection and access covers and cowlings. Connect ELT (if installed) wiring at connectors and anti-ice switch wiring terminals under cyclic box cover. Connect antenna leads and ground wires (if installed). Install covers and cowlings removed in preceding steps. Verify security. Verify security of removable and adjustable controls. Fasten cyclic, collective, and removable collective boot snaps. JUL 2023 Chapter 5 Inspections Page 5.17 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) HORIZONTAL CONTROL TUNNEL (Aft seats) Covers: Inspect condition. Verify marking legibility. Antenna Wiring & Connectors: Inspect condition. Verify no loose, chafed, frayed, or broken wires. Verify no damaged connectors. Verify neatness, proper routing and installation, and security. Cyclic Yoke: Inspect condition. Verify no cracks, corrosion, or fretting. Inspect spherical bearings per § 5-33. Verify proper installation, security, and operating clearance. Cyclic Fork: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Inspect rod end bearings per § 5-33. Verify proper installation, security, and operating clearance. Cyclic Horizontal Torque Tube: Examine accessible portion with inspection light and mirror. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no cracks around reinforcement blocks on both ends of torque tube. Verify proper installation, security, and operating clearance. Horizontal Push-Pull Tubes: Examine accessible portion with inspection light and mirror. Inspect condition per § 5-32. Verify no nicks, scratches, chafing, dents, cracks, or corrosion. Inspect rod end bearings per § 5-33; verify rod ends are centered and palnut and jam nut are tight. Check witness holes for proper thread engagement. Verify proper installation, security, and operating clearance. Page 5.18 Chapter 5 Inspections JUL 2023 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) HORIZONTAL CONTROL TUNNEL (Aft seats; continued) Fuel Cutoff and Throttle Control: Inspect condition. Verify proper fuel cutoff and throttle control clearance to installed equipment and surrounding structure. Verify proper installation and security. Cabin Heater Valve and Control: Inspect condition. Verify control clearance to installed equipment and surrounding structure. Verify heater valve security. Verify proper installation and smooth operation of valve. Flight Control Bellcranks: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Inspect spherical bearings per § 5-33. Verify proper installation, security, and operating clearance. Bellcrank Support: Inspect condition. Verify no cracks or corrosion in welds. Verify no cracks where support mounts to keel panels. Verify proper installation and security. Evaporator and Blower Assembly (Air Conditioning; if installed): Remove middle seat assembly and cover, and inspect condition. Verify refrigerant line security, no damage, and clearance to adjacent structure. Verify no loose, chafed, frayed, or broken wires. Verify proper installation and security of blower and evaporator components. Evaporator Drain Tubes and Valve (Air Conditioning; if installed): Remove middle seat assembly and cover, and covers inside left and right seat compartments to access drain system. Verify tubes are unobstructed. Function- check drain system by simultaneously squeezing drain tube and sediment tube near tee-fitting and verify check-valve ball moves up momentarily. VERTICAL CONTROL TUNNEL Vertical Push-Pull Tubes: Examine accessible portion with inspection light and mirror. Inspect condition per § 5-32. Verify no nicks, scratches, chafing, dents, cracks, or corrosion. Inspect rod end bearings per § 5-33; verify rod ends are centered and palnut and jam nut are tight. Check witness holes for proper thread engagement. Verify proper installation, security, and operating clearance. Beep Switch Actuator: Inspect condition. Verify proper control clearance to installed equipment and surrounding structure. Verify proper actuator installation, security, and operation. Tunnel Interior: Verify general cleanliness of tunnel interior. Inspect for fluid leaks or seepage; investigate cause and correct. Seat Backs: Inspect condition. Verify upholstery cleanliness and security. JUL 2020 Chapter 5 Inspections Page 5.19 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) CABIN BULKHEAD Blind Encoder & Engine Monitoring Unit (EMU): Inspect condition. Inspect wiring for obvious damage. Verify no cracks where units mount to bulkhead. Verify proper installation and security. Download EMU data as required per RR300 Series OMM. Fuse Block and Fuses (Air Conditioning; if installed): Inspect condition. Verify no corrosion. Verify correct fuse amperage and security. Antenna Wiring: Inspect condition. Verify no loose, chafed, frayed, or broken wires. Verify neatness, proper routing and installation, and security. Check grommets for proper installation. Pitot & Static Lines: Inspect pitot and static lines for obstructions, cracking, chafing, pinching, or kinking. Verify integrity of pitot and static line connections. Verify line security. Seat Back Interior: Verify general cleanliness of seat back interior. Inspect for fluid leaks or seepage; investigate cause and correct. Fuel Flow Meter Adapter (if installed): Refer to § 28-23. Visually inspect adapter for any obvious damage; verify proper installation and security. Inspect wiring for loose, chafed, frayed, or broken wires. Verify no damaged connectors. Verify wiring neatness, proper routing and installation, and security. Cabin Bulkhead: Examine accessible portion with inspection light and mirror. Verify no nicks, scratches, dents, cracks, corrosion, or loose rivets. Verify stiffener security. Verify upholstery cleanliness and security. Wiring: Inspect condition. Verify no loose, chafed, or broken, wires or terminals. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Antennas: Inspect condition. Verify no cracks where antennas mount to cowlings. Verify security. Close & Secure: Verify foreign objects are removed. Verify equipment security. Verify cleanliness of interior and of inspection and access covers and cowlings. Connect antenna leads and ground wires (if installed). Install covers and cowlings removed in preceding steps. Verify security. Page 5.20 Chapter 5 Inspections JUL 2020 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) BAGGAGE COMPARTMENT Door: Inspect condition. Verify proper operation of micro switch and COWL DOOR warning segment. Inspect hinges and latches for obvious defects. Verify security and proper latching/locking function. Carpet: Inspect condition. Verify no defects, tears, or material deterioration. Verify proper installation and security. Interior: Inspect condition. Verify no structural damage. Verify general cleanliness of baggage compartment. Verify any installed equipment or passenger cargo are secure. Generator Control Unit (GCU) & Wiring: Inspect condition. Verify no exposed, loose, chafed, or broken, wires & terminals. Verify proper installation and security of wiring covers and Generator Control Unit (GCU). BATTERY Lead-Acid Battery Installations: Inspect condition. Verify no cracks or corrosion on or near battery cable terminals. As required, perform capacity test or replace battery per manufacturer’s instructions. Verify battery cable security. Verify no corrosion in surrounding structure. Lithium-Ion Battery Installation (if equipped): Refer to § 96-12. Inspect condition. Verify no cracks or corrosion on or near battery terminals. Verify vent hose, comm connector wiring, and battery cable security. Replace both 9v back-up batteries under LH front seat. Perform scheduled maintenance as required. Verify no corrosion in surrounding structure. AUX FUEL SYSTEM (If equipped) Placards: Verify placard legibility, proper installation, and security. Aux Fuel Tank: Examine accessible portion with inspection light and mirror. Inspect condition of exterior and verify no leakage. Check bladder interior for foreign objects or debris. Verify security. Aux Fuel Tank Support: Examine accessible portion with inspection light and mirror. Inspect condition of exterior; verify no cracks or obvious damage. Verify security. Aux Fuel Hoses: Inspect condition. Verify no leakage, chafing, or obvious damage to fuel lines. Verify line clearance to installed equipment and surrounding structure. Verify security. JUL 2023 Chapter 5 Inspections Page 5.20A ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) AUX FUEL SYSTEM (If equipped; continued) Aux Fuel Gage Sender & Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify proper installation and security of sender and wiring. Aux Fuel Pump Wiring: Inspect condition. Verify no loose, chafed, or broken wires. Verify proper installation and security of wiring. Aux Fuel Cap: Inspect condition. Verify no damage or deterioration of gasket. Install cap and verify proper locking function. Verify security. Aux Fuel Tank Sump Drain: Inspect condition. Verify drain valve opens easily, drains fuel freely, springs closed, and seals completely. Inspect drain hose assembly for defects, tears, or material deterioration. Secure hose at tab near drain valve. MT183-1 Tool Kit: Inspect condition. Remove kit and verify kit contains loose parts listed in R66 Illustrated Parts Catalog. Clip kit to aux tank and verify security. PRESSURE FUELING SYSTEM (If equipped) Pressure Fueling System (optional): Perform scheduled inspections per § 28-67 Part A. Page 5.20B Chapter 5 Inspections JUL 2023 ROBINSON MAINTENANCE MANUAL MODEL R66 Intentionally Blank MAR 2025 Chapter 5 Inspections Page 5.21 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT Cowling Doors: Inspect condition. Verify proper operation of fasteners. Antenna Wiring & Connectors: Inspect condition. Verify no loose, chafed, frayed, or broken wires. Verify no damaged connectors. Verify neatness, proper routing and installation, and security. Check grommets for proper installation. Placards: Verify placard legibility, proper installation, and security. Refer to Chapter 11. Fuel Tank: Examine accessible portion with inspection light and mirror. Inspect condition of exterior and verify no leakage. Check bladder interior for foreign objects or debris. Verify security. Fuel Gage Sender & Wiring: Inspect condition. Verify no loose, chafed, or broken, wires or terminals. Verify proper installation and security of sender and wiring. Low-Fuel Switch Assembly Warning: Turn battery switch on. With a clean wooden dowel, gently depress low-fuel sender float in fuel bladder and verify LOW FUEL warning segment illuminates after approximate 1-second delay. Turn battery switch off. Fuel Cap: Inspect condition. Verify no damage or deterioration of gasket. Install cap and verify proper locking function. Verify security. Fuel Tank Rollover Vents: Inspect condition. Inspect Tygon® tube for defects, tears, or material deterioration. Verify proper safety wire installation and security. Verify 0.25 inch minimum clearance between cable assembly and vent assembly Tygon® tube; adjust cable as required. Verify no obstructions in vents. Fuel Tank Sump Drain: Inspect condition. Verify drain valve opens easily, drains fuel freely, springs closed, and seals completely. Inspect drain tube and clamp for defects, tears, or material deterioration. Clear fuel from drain tube and install clamp. Fuel Valve: Inspect condition. Verify cable and component security. Verify proper installation and (smooth) operation of valve. Page 5.21A Chapter 5 Inspections MAR 2025 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT (continued) Cabin Bulkhead: Inspect condition. Verify no deformation, buckling, wrinkling, nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets. Verify no leakage from fuel tanks. Verify security. Main Rotor Gearbox: Inspect condition. Verify no damage, material deterioration, or deformation of gearbox mounts. Verify no leakage at mast tube-to-gearbox attachment. Inspect mast tube for cracks. With ship on level ground, verify correct oil level and cleanliness through sight gage and adjust or flush as required. Verify security of Hall Effect senders and yoke magnets. Inspect oil lines for leakage, chafing, or obvious damage. Inspect oil pump mounting and fittings for leaking or obvious damage. Inspect gearbox oil filter for leakage or for tripped bypass indicator. Verify oil system proper installation and security. NOTE At 600 hours time in service or annually, whichever occurs first, remove chip detector and clean detector’s magnetic probe and adjacent metal body using a toothbrush and approved solvent per § 12-13 Part B. Service gearbox, change oil and filter, and clean chip detector at intervals recommended in § 1-90. Rotor Brake: Inspect condition. Verify integrity of brake pads and 0.030 inch minimum pad thickness. Verify brake pads are clear of engine shaft with brake released. Inspect micro switches for cracks. Verify no loose, chafed, or broken wires or terminals. Verify security. Inspect both pulleys (one at end of lever, one next to fuel tank) for cracks. Verify no frayed strands or binding of rotor brake activating cable. Verify proper routing and installation, security, and operation of brake and brake micro switch. Hydraulic Servo Support Frame: Inspect condition. Inspect rod ends per § 5-33. Use an inspection light and mirror to inspect all parts of each weld. Verify no cracks or corrosion in servo support. Verify proper installation and security. Jackshaft: Inspect condition. Verify no cracks or corrosion in welded assembly. Inspect jackshaft to vertical push-pull tube attachment. Inspect jackshaft aft support frame attachment and forward attachment rod end per § 5-33. Inspect C343-8 tube and rod ends linking jackshaft to aft servo. Verify security and proper operating clearance. MAR 2025 Chapter 5 Inspections Page 5.21B ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT (continued) Main Rotor Push-Pull Tubes: Examine accessible portion with inspection light and mirror. Inspect condition per § 5-32. Verify no nicks, scratches, chafing, dents, cracks or corrosion. Inspect rod end bearings per Section 5-33; verify rod ends are centered and palnut and jam nut are tight. Check witness holes for proper thread engagement. Verify proper installation, security, and operating clearance. Tail Rotor Push-Pull Tube & Forward Bellcrank: Examine accessible portion with inspection light and mirror. Inspect condition per § 5-32. Verify no nicks, scratches, chafing, dents, cracks, or corrosion. Inspect rod end bearings per § 5-33; verify rod ends are centered and palnut and jam nut are tight. Check witness holes for proper thread engagement. Inspect bellcrank and bellcrank sheet metal mounting for nicks, scratches, dents, cracks, or corrosion. Inspect spherical bearings per § 5-33. Verify proper installation, security, and operating clearance. Hydraulic Reservoir: Inspect condition. Verify no significant leakage. Replace filter and packing at intervals specified in § 1-90. Drain and flush hydraulic system per § 12-33 if oil has turned dark or emits bad odor. Add fluid as required. Verify security. CAUTION Cleanliness of hydraulic fluid is vital to proper system operation. Service hydraulic system with clean fluid from sealed containers. Verify funnels, tubing, and other service tooling is free of contaminants. Hydraulic Servos: Inspect condition. Inspect rod ends per § 5-33. Verify approximately 0.040 inch total free play at servo valve input. Hydraulic fluid seepage is permissible (“seepage” is evidence of fluids without flow, drips, or runs) provided fluid does not contaminate MRGB rubber mounts. Clean servo input rod end/clevis area with no-residue, nonalcoholic solvent as required. Verify no obvious defects and security of scissors at upper clevis of servos. Verify proper installation and clearance from surrounding structure through full control travel. CAUTION Use LPS PreSolve to clean hydraulic parts. Do not use alcohol. Page 5.21C Chapter 5 Inspections MAR 2025 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT (continued) Hydraulic-Servo Absorbent Pad (Recent Servos Only): If installed, examine white absorbent pad(s); replace pad if damaged. If pad is discolored, remove pad from tray, then use a roller to squeeze out absorbed fluid, or replace pad. Clean tray & install pad. Hydraulic Hoses, Lines, & Fittings: Inspect condition. Verify no leakage, chafing, or obvious damage to hydraulic lines. Verify integrity of connections. Verify fluid line clearance to installed equipment and surrounding structure and sufficient fluid hose slack available through full control travel. Verify proper installation and security. Hydraulic Pump: Inspect condition. Inspect Telatemp per § 5-35. Verify no significant leakage. Verify proper installation and security. Upper Steel Tube Frame: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no chafing where wires, hoses, or clamps attach to frame. Examine each weld for cracks with an inspection light and mirror. CAUTION Upper steel tube frame is fatigue loaded and therefore susceptible to fatigue cracks. Inspect all joints thoroughly. F908-1 (Tail Rotor Drive) Yoke Assembly: Inspect condition. Verify no cracks, corrosion, or fretting. Verify proper installation, security, and operating clearance. Verify security of magnets. G779-1 Pulley (Air Conditioning; if installed): Inspect condition. Verify no cracks, corrosion, or fretting. Verify no nicks or sharp edges in fins that could damage v-belt. Verify proper installation, security, and operating clearance. V-Belt (Air Conditioning; if installed): Inspect condition. Replace belt if exhibiting frayed edges, excessive cracking, heat damage, or rubber deterioration. Verify 4.5–5.5 lb of force applied mid-span deflects belt 0.16-inch; adjust as required per § 21-21. MAR 2025 Chapter 5 Inspections Page 5.21D ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT (continued) Compressor Assembly (Air Conditioning; if installed): Inspect condition, including integrity of belt-tension slotted plate. Verify security of mounting. Verify no loose, chafed, frayed, or broken wires. Verify proper installation and security of pressure switches, snubber, and refrigerant lines. Refrigerant Hose Assemblies (Air Conditioning; if installed): Verify security, no damage, and clearance to adjacent structure. Verify dust caps installed on service fittings where lines mount to compressor. F196-1 (Tail Rotor Drive) Fan Shaft: Inspect condition. Verify no shaft corrosion. Remove any light surface corrosion and apply wax or suitable corrosion inhibitor. Verify no cracks, corrosion, or fretting in fore and aft weldment. Verify proper installation, security, and operating clearance. FIGURE 5-4A FLEX PLATE INSPECTION Page 5.22 Chapter 5 Inspections MAR 2025 ROBINSON MAINTENANCE MANUAL ive special a ese Inspect entire periphery; verify no cracks, nicks, or corrosion. Inspect area around washers; verify no fretting or cracks. MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT (continued) C947-3 (Tail Rotor Drive) Plate Assemblies, Forward and Intermediate: Refer to Figure 5-4A. Inspect condition. Verify no distortion, nicks, scratches, cracks, corrosion, or fretting. If fretting is detected, contact RHC Technical Support. Verify bonded washers are installed on both sides of each flex plate ear. Verify proper installation, security, and operating clearance. Fanwheel Assembly and Scroll Assembly: Clean fanwheel blades and inspect condition. Verify no cracks, corrosion, or obvious damage on blade leading edges or fan assembly. Verify 0.10 inch minimum gap between G174-1 fanwheel assembly and forward and aft F305-5 inlets. Check gap all the way around; rotate fanwheel and check gap again (several positions). If gap does not meet minimum limit, trim inlets per § 79-11. Verify proper installation, security, and operating clearance. Verify no cracks or damage to scroll assembly. Emergency Locator Transmitter (ELT; if installed): In accordance with local regulation, test per ELT manufacturer instructions. If 406 Mhz ELT, confirm programming tag matches helicopter registration. If RHC installation, inspect condition of both primary hook & loop strap and secondary buckle strap; replace strap(s) if damaged or deteriorated. Verify ELT security and clearance to drive train. Pitot Line & Static Vent: Inspect pitot and static lines for obstructions, cracking, chafing, pinching or kinking. Verify integrity of pitot and static line connections. Verify line security. Horizontal Firewall: Inspect condition. Verify no deformation, buckling, wrinkling, nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets. Verify no leakage from fuel tanks. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Antennas: Inspect condition. Verify no cracks where antennas mount to cowling. Verify security. Cowling Doors: Inspect condition. Verify proper operation of fasteners. F910-1 (Main Rotor Drive) Yoke: Inspect condition. Verify no cracks, corrosion, or fretting. Verify proper installation, security, and operating clearance. MAY 2021 Chapter 5 Inspections Page 5.23 ROBINSON MAINTENANCE MANUAL MODEL R66 Page 5.24 Chapter 5 Inspections MAY 2021 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT (continued) A947-2 (Main Rotor Drive) Plate Assemblies: Refer to Figure 5-4A. Inspect condition. Verify no distortion, nicks, scratches, cracks, corrosion, or fretting. If fretting is detected, contact RHC Technical Support. Verify bonded washers are installed on both sides of each flex plate ear. Verify proper installation, security, and operating clearance. F642 (Engine) Shaft Weldment: Inspect condition. Verify 0.2 inch minimum clearance between shaft weldment and firewall grommet; verify equal gap concentrically between shaft and box assembly hole edges. Adjust F174-1 support weldment rod ends per § 53-31 as required. Rotate shaft and verify no cracks, corrosion, or fretting. Verify proper installation, security, and operating clearance. Engine Firewall: Inspect condition. Verify no deformation, buckling, wrinkling, nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets. Verify no leakage from fuel tanks. Engine Oil Tank: Inspect condition. Verify no leakage or obvious damage to oil tank exterior. Check tank interior for foreign objects. Add oil as required per R66 POH Section 8. Verify tank security. Tailcone Attachment: Inspect condition. Verify no cracks near fasteners attaching tailcone to upper frame. Verify proper installation and security. Upper Steel Tube Frame: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no chafing where wires, hoses, or clamps attach to frame. Examine each weld for cracks with an inspection light and mirror. CAUTION Upper steel tube frame is fatigue loaded and therefore suscep- tible to fatigue cracks. Inspect all joints thoroughly. Antenna Wiring & Connectors: Inspect condition. Verify no loose, chafed, frayed, or broken wires. Verify no damaged connectors. Verify neatness, proper routing and installation, and security. Check grommets for proper installation. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. ROBINSON MAINTENANCE MANUAL MODEL R66 APR 2019 Chapter 5 Inspections Page 5.25 5-45 100-Hour / Annual Inspection (continued) MAIN ROTOR GEARBOX COMPARTMENT (continued) Antennas: Inspect condition. Verify no cracks where antennas mount to cowling. Verify security. Close & Secure: Verify foreign objects are removed. Verify equipment security. Verify cleanliness of interior and of inspection and access doors and cowlings. Connect antenna leads and ground wires, if installed. Install/close doors and cowlings removed in preceding steps. Verify security. ROBINSON MAINTENANCE MANUAL R66 SERIES Intentionally Blank Page 5.26 Chapter 5 Inspections APR 2019 ROBINSON MAINTENANCE MANUAL R66 SERIES 5-45 100-Hour / Annual Inspection (continued) ENGINE Refer to RR300 Series OMM, and applicable engine component manufacturer’s maintenance publications for service and inspection procedures. Additional service and inspection intervals are specified in § 1-90. NOTE For engine-related matters, if there is a conflict between this manual and Rolls-Royce instructions, Rolls-Royce instructions take precedence. Notify RHC of discrepancy. Inlet Plenum and Filter Bypass Indication: Inspect plenum condition. Verify no foreign object debris or loose items. Turn battery switch on. Verify annunciator panel warning segment illuminates when bypass doors are opened individually, then simultaneously. Turn battery switch off. Standard (Foam) Air Filter Assembly: Inspect condition. Verify no tears, punctures, or damage to filter media or cage assembly; verify no corrosion, cracks, or distortion to filter assembly components. Service filter as required per § 71-21, Part D. Verify proper installation and security. Inlet Barrier Filter (if installed): Inspect condition. Verify no tears, punctures, or damage to filter media or cage assembly; verify no corrosion, cracks, or distortion to filter assembly components. Service or replace filter assemblies as required per § 71-21, Part E. Note indication on filter maintenance aid. Verify proper installation and security. Engine Hoses: Inspect condition. Verify no rips, holes, or collapsed areas (gently squeeze hose with finger tips). Verify proper installation and security. Exhaust Pipe: Inspect condition. Verify no cracks (illuminating exterior with bright light while viewing interior facilitates crack detection). Inspect condition and security of F173-1 struts. Inspect condition and security of gearbox vent and clamps. Starter-Generator & Wiring: Inspect condition. Verify no loose, chafed, frayed, or broken wires. Verify no damaged connectors. Verify neatness, proper routing and installation, and security. Starter-Generator Hose and Filter: Inspect condition. Verify no rips, holes, or collapsed areas in hose (gently squeeze hose with finger tips). Verify no tears, punctures, or damage to filter foam; may be cleaned with mild soap (pH between 7 & 9) and warm water solution. JUL 2023 Chapter 5 Inspections Page 5.27 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) ENGINE (continued) Engine Oil and Oil Filter: Add oil as required per R66 POH Section 8. Change oil and oil filter as required per RR300 OMM. Verify filter security. Oil Lines: Inspect condition. Verify no leakage where lines connect to tank. Verify no leakage, chafing, or obvious damage to oil lines. Verify line clearance to installed equipment and surrounding structure. Verify security. Cooling Duct and Oil Coolers: Verify installation security with no cracks in duct or mounting. Verify cooler line connections are tight and coolers have no nicks, dents, cracks, or corrosion. Verify duct and cooler cores are free of debris to allow full airflow. Power Turbine Governor (PTG) Control: Refer to Figure 76-2. Verify D333-13 fitting in PTG input lever moves in and out slightly with light finger pressure. If D333-13 fitting does not move in response to light finger pressure then follow compliance procedure in R66 Service Bulletin SB-01. Fuel Control Unit (FCU) and Control Rigging: Verify proper routing and security of throttle and fuel cutoff controls; verify smooth actuation of both controls without binding. Verify FCU throttle arm contacts idle stop with twist grip closed and contacts maximum throttle stop with twist grip open. Verify FCU cutoff lever rests in detent when control is OFF and has 0.030–0.090 inch clearance from maximum fuel stop when control is ON. Fuel Filter: Inspect condition; service fuel filter per RR300 OMM, as required. Verify proper installation and security of wiring and housing. Fuel Hose: Inspect condition. Verify no leakage, chafing, or obvious damage to tank-to-engine hose. Verify hose clearance to installed equipment and surrounding structure. Verify security. Fuel Flow Meter Transducer (if installed): Refer to § 28-23. Visually inspect fuel control unit-to-transducer fuel tube connections, transducer, and reducer connections to transducer & check valve for evidence of leakage. Visually inspect components for any obvious damage; verify proper installation and security. Verify no damaged connectors. Verify wiring neatness, proper routing and installation, and security. Page 5.28 Chapter 5 Inspections JUL 2023 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) ENGINE (continued) Firewalls: Inspect condition. Verify no deformation, buckling, wrinkling, cracks, corrosion, fretting, or loose rivets. Pay particular attention to structural attachment points. Inspect condition of engine-to-firewall seal. Verify no open holes. WARNING Open holes in engine-to-firewall seals are potential fire leak paths. Engine Mounts: Inspect condition. Verify no cracks or corrosion in engine mount weldment. Verify safety wire and security of mounting bolts. Lower Steel Tube Frame: Inspect condition. Verify no nicks, scratches, dents, cracks, or corrosion. Verify no chafing where wires, hoses, or clamps attach to frame. Examine each weld for cracks with an inspection light and mirror. Condenser and Fan Assemblies (Air Conditioning; if installed): Inspect condition. Verify security of fans, box assembly, condenser, and firewall supports. Verify security of desiccant cap. Refrigerant Line Assemblies (Air Conditioning; if installed): Inspect condition. Verify security, no damage, and clearance to adjacent structure. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Check for heat or fluid damage. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Close & Secure: Verify foreign objects are removed. Verify equipment security. Verify cleanliness of interior and of cover or cowling. Install/close inspection covers or cowlings removed in preceding steps. Verify security. MAR 2025 Chapter 5 Inspections Page 5.28A ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) TAILCONE & STABILIZERS Inspection Plugs: Inspect condition. Verify proper operation of fasteners. Tail Rotor Drive Shaft Assembly: Examine accessible portion through inspection holes with inspection light and mirror. Verify no cracks, corrosion, or fretting in fore and aft weldment. Verify no evidence of drive shaft contact with tailcone bays. Verify no bowing, bends, dents, cracks, or corrosion. Perform tail rotor drive shaft runout per § 65-21. Verify proper installation, security, and operating clearance. CAUTION Bowing, bends, dents, cracks, or corrosion are cause for immediate replacement of tail rotor drive shaft. Tail Rotor Push-Pull Tube & Forward Bellcrank: Examine accessible portion through inspection holes with inspection light and mirror. Inspect condition per § 5-32. Verify no nicks, scratches, chafing, dents, cracks, or corrosion. Inspect rod end bearings per § 5-33; verify rod ends are centered and palnut and jam nut are tight. Check witness holes for proper thread engagement. Inspect bellcrank and bellcrank mount for nicks, scratches, dents, cracks, or corrosion. Inspect spherical bearings per § 5-33. Verify proper installation, security, and operating clearance. Verify tail rotor guard mounting screw shanks clear push-pull tube. Tail Rotor Drive Shaft Hanger Bearing & Hanger: Inspect condition. Inspect bearing for obvious damage. Verify integrity of bearing seals. Verify bearing’s inner race-to-drive shaft torque stripe is intact and no evidence of bearing slippage on shaft. Verify no bends, cracks, corrosion, or obvious damage to hanger and hanger mount to tailcone bulkhead. Verify proper installation, security, and smooth operation. Tail Rotor Drive Shaft Damper Assembly: Inspect condition. Inspect bearing for obvious damage. Verify integrity of bearing seals. Inspect bearing housing for cracks or corrosion. Verify bearing’s inner race- to-drive shaft torque stripe is intact and no evidence of bearing slippage. Verify no bends, cracks, corrosion or obvious damage to friction arms and (Teflon) bearings. Verify proper installation, security, and smooth operation. Tailcone Interior: Inspect condition. Verify no nicks, scratches, dents, cracks, corrosion, fretting or loose rivets. Verify no cracks where damper assembly mounts to tailcone. Verify no excessive wear in bulkhead bushings from push-pull tubes. Retrieve and discard trapped debris. Page 5.28B Chapter 5 Inspections MAR 2025 ROBINSON MAINTENANCE MANUAL MODEL R66 MAR 2025 Chapter 5 Inspections Page 5.29 5-45 100-Hour / Annual Inspection (continued) TAILCONE & STABILIZERS (continued) Tailcone Exterior: Inspect condition. Refer to § 53-41. Inspect tailcone exterior for nicks, scratches, dents, cracks, corrosion, fretting or loose rivets. Verify no obstructions in drain hole at forward edge of each bay (except forward bay). F050-2 Horizontal Stabilizer (if installed): Inspect condition. Verify no nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets. Verify security. Empennage: Inspect condition. Verify no nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets on skins or near attachment points. Check tail rotor skid for evidence of tail rotor or tail rotor skid strike. Refer to § 5-61 for tail rotor skid strike inspection criteria. Verify no obstructions in lower vertical stabilizer and skid drain holes. Verify proper installation and security. Aft Navigation Light: Inspect condition. Verify no cracks where aft navigation light mounts to empennage. Verify lens cleanliness, clarity, and security. Verify proper operation. Antennas: Inspect condition. Verify no cracks where antennas mount to tailcone. Verify security. Anti-Collision Light: Inspect condition. Verify no cracks where anti-collision light mounts to tailcone. Verify lens cleanliness, clarity, and security. Verify proper operation. Tail Rotor Visual Warning Guard: Inspect condition. Verify no cracks where guard mounts to tailcone. Inspect guard welds for cracks or corrosion. Verify security. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Close & Secure: Verify foreign objects are removed. Verify equipment security. Verify cleanliness of interior and of inspection plugs. Install plugs removed in preceding steps. Verify security. ROBINSON MAINTENANCE MANUAL MODEL R66 Page 5.30 Chapter 5 Inspections MAR 2025 5-45 100-Hour / Annual Inspection (continued) TAIL ROTOR & TAIL ROTOR GEARBOX NOTE Verify proper hardware installation securing plastic inspection cover. Longer screws could contact aft flex coupling and yoke. Plastic Inspection Cover: Clean cover and inspect condition. Replace as required. C947-3 (Tail Rotor Drive) Plate Assembly, Aft: Refer to Figure 5-4A. Inspect condition. Verify no distortion, nicks, scratches, cracks, corrosion, and fretting. If fretting is detected, contact RHC Technical Support. Verify bonded washers are installed on both sides of each flex plate ear. Verify proper installation, security, and operating clearance. Tail Rotor Gearbox Input Yoke: Inspect condition. Verify no cracks, corrosion, or fretting. Inspect weld for cracks or corrosion. Verify proper installation, security, and operating clearance. Tail Rotor Gearbox: Inspect condition. Verify gearbox-to-tailcone mounting security. Verify no leakage at input or output seals, chip detector, vent plug-filler assembly, or sight gage. With ship on level ground, verify correct oil level and oil cleanliness through sight gage and adjust or flush as required. Inspect Telatemp per § 5-35. Inspect output shaft for nicks, scratches, dents, cracks, or corrosion. Verify proper installation of safety wire (if installed). Gearbox S/Ns 9684 & prior: using 10X magnification, visually inspect four curved surfaces on input cartridge per Figure 5-4B; if cracking is detected, remove gearbox from service and perform C148 Bulkhead Inspection per § 5-75. FIGURE 5-4B TRGB INPUT CARTRIDGE INSPECTION ROBINSON MAINTENANCE MANUAL MODEL R66 2 3 4 (VIEW LOOKING FORWARD) 5-45 100-Hour / Annual Inspection (continued) TAIL ROTOR & TAIL ROTOR GEARBOX (continued) Pitch Control Bearing Assembly & Aft Bellcrank: Inspect condition. Verify pitch control assembly has less than 0.25 inch rotational play measured at pitch link attach bolt. Verify no leakage at bearing seals. Verify no nicks, scratches, dents, cracks, or corrosion on pitch control housing or bellcrank. Inspect bellcrank spherical bearings per § 5-33. Inspect spherical bearing atop stud protruding from underside of pitch control for cracks. Verify proper installation, security, and smooth actuation without binding. NOTE B345-4 tail rotor pitch links can have different shaft diameters (0.250 inch or 0.300 inch). Balance tail rotor per § 18-20 if a different shaft diameter pitch link is installed. Pitch Links: Inspect condition. Inspect rod ends per § 5-33. Remove and reinstall pitch links with outboard end inboard and inboard end outboard as required to obtain maximum service life; additionally, an optional A215-012 O-ring may be installed on A115-1 spacer under bolt head at pitch control. Reinstall chordwise weights at respective attachment points for balance purposes. Verify proper installation of A115-1 spacers. Verify proper installation, security and operating clearance. Tail Rotor Blades: Refer to R66 SB-41. Inspect condition. Refer to § 64-30 for damage limits and repair. Verify no looseness between spherical bearing outer races and root fittings. Inspect bearings per § 5-33. Verify no obstructions in blade tip drain holes. Verify proper installation, security, and pitch change operation. WARNING Structural damage may occur if compressed air is applied to blade tip drain holes. Tail Rotor Hub: Inspect condition. Verify no nicks, scratches, gouges, dents, cracks, or corrosion. Inspect elastomeric teeter bearings per § 5-34. Teeter rotor hub and verify teeter bearing bolt, spacers, and nuts do not rotate. Verify hub teeters smoothly. Verify proper installation and security of blade bolts. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. JUL 2023 Chapter 5 Inspections Page 5.31 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAST FAIRING Mast Fairing: Inspect condition. Verify no nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets. Verify no yielding or cracking of pitot line and fuel vent restraint assembly. NOTE Yielding can be caused by over tightening screws in restraint nutplates. Upper & Lower Ribs: Inspect condition. Inspect for cracks especially around mast tube attachments. Verify proper installation and security of ribs and lower rib clamp. Vertical Push-Pull Tubes: Examine accessible portion with inspection light and mirror. Inspect condition per § 5-32. Verify no nicks, scratches, chafing, dents, cracks or corrosion. Inspect rod end bearings per § 5-33; verify rod ends are centered and palnut and jam nut are tight. Check witness holes for proper thread engagement. Verify proper installation, security, and operating clearance. Pitot Tube & Line: Inspect pitot lines for obstructions, cracking, chafing, pinching or kinking. Verify integrity of pitot and static line connections. Verify proper routing and security of pitot tube and line. Verify no cracks where pitot tube mounts to mast fairing. Verify no obstructions in pitot tube. Fuel Vent Weldment and Tygon® Tubes: Inspect condition. Verify no obstructions, cracking, chafing, pinching or kinking in plastic tubes. Inspect vents for cracks or obvious damage. Verify proper installation and security of safety wire. Swashplate Upper Scissors: Inspect condition. Verify bearing play within limits referenced in § 67-40, steps 9 and 10. Closely examine scissor linkage while a second person raises and lowers collective stick. Verify bolts and washers rotate together through full control travel without binding. Inspect fork assembly rod end bearing per § 5-33; verify rod end is centered and palnut and jam nut are tight. Verify proper installation of all parts, part security, and operating clearance. Page 5.32 Chapter 5 Inspections JUL 2023 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAST FAIRING (continued) Swashplate Lower Scissors: Inspect condition. Verify bearing play within limits referenced in § 67-40, steps 9 and 10. Closely examine scissor linkage while a second person raises and lowers collective stick. Verify bolts and washers rotate together through full control travel without binding. Inspect fork assembly rod end bearing per § 5-33; verify rod end is centered and palnut and jam nut are tight. Verify proper installation of all parts, part security, and operating clearance. Swashplate Slider Tube: Inspect condition. Verify no cracks, corrosion, or loose rivets near tube base flange. Verify no damage or wearing through of anodized coating on tube surface. When viewed under 10X magnification, minute "checkerboarding" of anodized surface is normal. Swashplate Interior: Remove swashplate boot lower ty-rap. Lift boot from swashplate, and verify no boot defects, tears, or material deterioration. Examine swashplate interior with inspection light and mirror. Verify no corrosion or debris between main rotor drive shaft and inside of slider tube. Install swashplate boot lower ty-rap. Verify proper boot position, security, and operating clearance. Swashplate: Inspect condition. Verify no nicks, scratches, gouges, dents, cracks, or corrosion. Verify 0.020 inch maximum radial play between swashplate ball and slider tube. Rotate rotor by hand and verify no rough or dry bearings. Verify proper operation. Swashplate Shimming: Closely examine area between lower swashplate and swashplate ball while a second person slowly raises and lowers collective stick. Verify synchronized movement of swashplate ball with swashplate when swashplate reverses direction. NOTE Swashplate shimming is required when swashplate ball lags collective inputs, indicating axial play. Shim swashplate per Chapter 67. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Close & Secure: Verify foreign objects are removed. Verify equipment security. Verify cleanliness of interior and of access fairing. Close mast fairing and verify security. JUL 2023 Chapter 5 Inspections Page 5.33 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) ROTOR HUB & MAIN ROTOR BLADES Teeter Stops & Teeter Stop Brackets: Inspect both urethane teeter stops and associated stainless steel brackets. Replace stops if cracked due to weathering. If stops evidence pinching and/or brackets are deformed, excessive MR teetering has occurred; contact RHC Technical Support for further instructions. Droop Stops: Cone and support both MR blades. Inspect curved bottoms of both aluminum droop stops where spindle tusks contact; replace any droop stop if wear exceeds 0.030 inch. Hub: Inspect condition. Verify no nicks, scratches, gouges, dents, cracks, or corrosion. Verify no brown or black residue indicating bearing wear. Verify proper installation and security. Hinge Bolts: Inspect condition. Check blade hinge friction by lifting blades until spindle tusks clear droop stops. Hold one blade level and cone opposite blade; rotor hub must not teeter as blade is coned. Repeat check on opposite blade. Verify cotter pins are installed and secure. Verify bolt heads and nuts are torque striped to thrust washers. Pitch Links & Rod Ends: Inspect condition. Inspect rod end bearings per § 5-33; verify rod ends are centered and palnut & jam nut torque stripes are acceptable. Verify correct orientation of C115-1 spacers. Check witness holes for proper thread engagement. Verify proper installation of safety wire (if applicable). Blade Spindles & Root Fittings: Inspect condition. Verify no obvious damage to visible portions of blade spindles and pitch horns. Verify no obvious damage to, and no missing paint from, blade root fittings, especially in area adjacent to inboard edges of blade skin and doublers. Blade Boots: Inspect condition. Verify no boot defects or oil leakage. Verify boot security. Verify clearance from hub assembly through full control travel. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. Main Rotor Blade Tip Maintenance: Perform main rotor blade tip maintenance per § 62-60. Page 5.34 Chapter 5 Inspections JUL 2023 ROBINSON MAINTENANCE MANUAL MODEL R66 MAY 2021 Chapter 5 Inspections Page 5.34A 5-45 100-Hour / Annual Inspection (continued) ROTOR HUB & MAIN ROTOR BLADES (continued) Blade Inspection and Care: Refer to § 62-40. Inspect skins and doublers for scratches and corrosion. Inspect blades for dents, local deformations, and voids. As required, wax blades with soft cleaning cloths using carnauba-type wax (such as SC Johnson® Paste Wax). Ensure tip cover and blade tip drain holes are unobstructed. Verify placard legibility and remove old tracking tape and/or residue. WARNING Structural damage may occur if compressed air is applied to blade tip drain holes. ROBINSON MAINTENANCE MANUAL MODEL R66 Intentionally Blank Page 5.34B Chapter 5 Inspections MAY 2021 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) LANDING GEAR Landing Gear Strut Fairings: Open as required to access landing gear structure for inspection. Inspect condition. Verify no nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets. Verify hose clamp security and acceptable general cleanliness of fairing interior. Close and secure fairings. Skid Tubes & Shoes: Inspect condition. Verify skid tube and skid shoe wear is within limits specified in §§ 32-30 & 32-31. Verify drain holes are not obstructed. Verify security of rain caps; if rain cap is loose or damaged, verify no internal corrosion. Verify security of ground handling wheel brackets and step(s) if installed. Struts Assemblies: Inspect condition. Verify no cracks or corrosion, especially at collar and gusset joints and in weld areas at bottom of struts. Torque-check strut-to-skid-tube bolts. Verify security. Cross Tubes: Inspect condition. With helicopter on level ground, verify minimum tail skid height per § 32-20. Verify no cracks, corrosion, or fretting at elbows. Verify security of (clear plastic) rain caps; if rain cap is loose or damaged, verify no internal corrosion. (Note that one vent hole per cross tube is located near left or right end of tube to prevent pressurization.) Landing Gear Attach Points: Inspect condition. Verify no buckling, cracks, fretting, or loose fasteners. Inspect mounts and verify no loose swages or worn bearings. Fasteners & Torque Stripes: Inspect condition. Verify proper installation and security of fasteners. Renew deteriorated torque stripes per Figure 5-1. D679 Cylinder assembly (Pop-out floats; if installed): Inspect condition. Verify security. Verify pressure gage indicates correct pressure for ambient temperature; refer to placard on cylinder for limits. Inflation manifold (Pop-out floats; if installed): Inspect condition. Verify no chafing or pinching of hoses, especially where hoses pass though structure. Float assemblies (Pop-out floats; if installed): Inspect condition of stowed floats. Verify no holes, cuts, tears, abrasion through or unraveling of, float covers. If cover damage is found, inflate and inspect floats per § 32-64. Annually apply A257-7 dry-film lubricant to float cover snap mating surfaces. Verify snaps and hook-and-loop fasteners are properly secured. Verify float-to-skid attachment security. JUL 2023 Chapter 5 Inspections Page 5.35 ROBINSON MAINTENANCE MANUAL MODEL R66 Page 5.36 Chapter 5 Inspections JUL 2023 5-45 100-Hour / Annual Inspection (continued) CABIN General Interior: Inspect condition. Verify general cleanliness of cabin and seat compartment interior. Verify no loose objects or equipment, which could foul controls or injure occupants in a hard landing. Verify legibility of placards and markings. Verify serviceable condition of switches, knobs, handles, and other controls. Seat Belts & Shoulder Harnesses: Inspect condition. Verify no fraying or broken stitching of seat belts or shoulder harnesses. Verify no significant UV damage. Check inertia reels for proper operation by pulling harness quickly to verify locking function. Check buckles for proper operation. Check belt and reel attachment points for security. Verify no cracks in seat belt anchor welds. Verify security. NOTE TSO tag not required on factory-installed harnesses. Cyclic Guard (if installed): Inspect condition of cyclic guard. Verify security and proper operation. Windshields & Windows: Inspect condition. Verify no significant UV damage (yellowing). Minor defects or imperfections that do not impair pilot visibility or indicate impending structural failure are acceptable. Refer to § 52-30 for damage and repair limits. Verify proper installation and security. Static Ports: Inspect condition. Verify no obstructions. ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) CABIN (continued) Yaw String: Inspect condition. Verify minimum string length is 3 inches on each side of clip. Verify security. Landing & Taxi Lights: Inspect condition. Verify lens cleanliness, clarity, and security. Verify proper operation. Landing Light Retainer & Support: Inspect condition. Verify no cracks where retainer mounts to support. Verify security. Left & Right Navigation Lights: Inspect condition. Verify no cracks where right and left navigation lights mount to fuselage. Verify red left, green right, lens cleanliness, clarity, and security. Verify proper operation. Exterior: Inspect condition. Inspect cabin exterior for nicks, scratches, dents, cracks, corrosion, fretting, or loose rivets. Loose rivets may be indicated by cracked paint and/or black residue around heads. Verify general cleanliness. Doors: Inspect condition. Verify no cracks and proper fit of door-to-door frame. Verify no structural cracks near door hinges or latches. Verify proper operation of door latching and locking mechanisms. Ensure door hinge pins are secured with cotter rings. Verify security of hinge mounting screws. Verify proper installation and operation of gas struts and door vent assembly. SPECIAL EQUIPMENT Transmit and Intercom Switches: Verify proper operation of special transmit and intercom switches. PA/Siren Speaker: Inspect condition. Verify no cracks in speaker. Verify security of mounting. Wiring: Inspect condition. Verify no loose, chafed, or broken wires or terminals. Verify neatness, proper routing and installation, and security. LIFE-LIMITED PARTS, PARTS WITH A RECOMMENDED TBO OR REPLACEMENT TIME, ADs, & SBs Life-Limited Parts: Refer to § 4-10. Verify life-limited parts correspond with aircraft maintenance records. Verify life-limited parts have sufficient time remaining for projected operations. Parts with a Recommended Time Between Overhauls (TBO) or Replacement Time: Refer to § 1-92. Verify parts with a recommended TBO or replacement time correspond with aircraft maintenance records. Verify parts with a recommended TBO or replacement time have sufficient time remaining for projected operations. MAY 2021 Chapter 5 Inspections Page 5.37 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) LIFE-LIMITED PARTS, PARTS WITH A RECOMMENDED TBO OR REPLACEMENT TIME, ADs, & SBs Airframe and Engine Accessories: Refer to § 1-92 and accessory manufacturer’s maintenance publications. Verify accessories correspond with aircraft maintenance records. Verify accessories scheduled for maintenance have sufficient time remaining for projected operations. Airworthiness Directives: Verify applicable airframe, engine, and accessory Airworthiness Directives (ADs) have been performed according to AD compliance procedures. Some helicopters may be affected by ADs that require recurring inspections at less than 100-hour or annual intervals. Recent U.S. Airworthiness Directives are online at www.faa.gov. Service Bulletins and Letters: Verify applicable airframe, engine, and accessory Service Bulletins (SBs) and Service Letters (SLs) have been complied with according to manufacturers’ instructions. Some helicopters may be affected by SBs or SLs that require recurring inspections at less than 100-hour or annual intervals. RHC Service Bulletins and Service Letters are online at www.robinsonheli.com under the Publications tab. REQUIRED DOCUMENTS AND PLACARDS Documents: Check that required documents (Airworthiness Certificate, Registration, applicable Radio Station License, Pilot’s Operating Handbook, Equipment List/Weight & Balance Data) are onboard, legible, and current. Placards: Verify required placards are properly installed, legible, and current. Refer to Pilot’s Operating Handbook Section 2 for placard requirements. INSPECTION AND ACCESS COVERS Foreign Objects Removed: Verify all tools, loose hardware, rags, and other foreign objects are removed from helicopter. Covers Closed and Secure: Refer to § 6-70. Install/close inspection and access covers and cowlings removed in preceding steps. Verify proper installation and security. Page 5.38 Chapter 5 Inspections MAY 2021 ROBINSON MAINTENANCE MANUAL MODEL R66 5-45 100-Hour / Annual Inspection (continued) MAINTENANCE RECORDS Maintenance Records: Verify maintenance records are accurate, legible, and complete. Enter maintenance performed (such as part replacement, equipment adjustments, servicing, and lubrication) and inspection data. Data must include a description of (or reference to data acceptable to the Administrator) the work performed, date, helicopter total time in service, signature, certificate type and certificate number of person approving helicopter for return to service. Inspection Procedures and Checklist completed: Mechanic’s signature: Date: MAY 2021 Chapter 5 Inspections Page 5.38A ROBINSON MAINTENANCE MANUAL MODEL R66 Intentionally Blank Page 5.38B Chapter 5 Inspections MAY 2021 ROBINSON MAINTENANCE MANUAL MODEL R66 JUL 2023 Chapter 5 Inspections Page 5.39 5-50 2000-Hour/12-Year Inspection NOTE Fuel bladder(s) are on condition. NOTE KI-6602 2000-Hour Inspection Kit contents are available online at https://robinsonheli.com for review. NOTE 12-Year Inspection is only required for helicopters that have accumulated 12 years in service and less than 2000 hours time in service since new, since last 2000-hour inspection, or since last 12-year inspection. 1. Refer to helicopter maintenance records and § 4-30; replace life-limited parts, or next higher assemblies, as required. 2. Refer to helicopter maintenance records and § 1-92; perform additional component maintenance, as required. 3. Visually inspect stabilizers. Verify no cracks, corrosion, loose rivets, dents, or deformation. 4. Remove fuel bladder(s) per Chapter 28. Visually inspect interior and exterior. Verify no corrosion, residue, microbial growth, or damage to fabric. Visually inspect adjacent structure for evidence of bladder leakage. Replace roll-over vent valve O-rings and packings per § 28-11. Remove any foreign object debris. Install bladder(s) per Chapter 28. 5. Perform (engine driveline) forward flex plate shimming per § 63-11 and (tail rotor driveline) intermediate flex plate shimming per § 65-30. 6. Fill and bleed hydraulic system per § 12-34 as required. 7. Drain engine oil per § 12-60; utilize a suitable clean container if reuse of oil is intended. Using a borescope or remote camera, inspect oil tank internal baffle and welds for signs of cracking. If cracks are detected, or if a broken baffle is found, replace oil tank per § 79-20. Add engine oil per § 12-60. 8. Perform main rotor flight control and blade angle rigging per §§ 18-30 and 18-40. 9. Perform tail rotor flight control and blade rigging per §§ 18-50 and 18-60. 10. If installed, perform leak check of air conditioning system per § 12-83. 11. Perform 100-Hour / Annual Maintenance and Inspection per § 5-45. 12. Weigh helicopter per § 8-20. ROBINSON MAINTENANCE MANUAL MODEL R66 Page 5.39A Chapter 5 Inspections JUL 2023 5-50 2000-Hour/12-Year Inspection (continued) 13. Balance tail rotor per § 18-20. Track and balance main rotor per § 18-10. Perform flight checks per § 5-43. 14. Drain and flush tail rotor gearbox per § 12-23. 15. Make appropriate maintenance record entries. Enter maintenance performed (such as part replacement, equipment adjustments, weighing, servicing, and lubrication) and inspection data. Data must include a description of (or reference to data acceptable to the Administrator) the work performed, date, helicopter total time in service, signature, certificate type and certificate number of person approving aircraft return to service. 5-51 C258-5 Main Rotor Pitch Link Assembly Inspection 1. Temporarily mark each pitch link and associated swashplate ear with unique identifiers, such as different colors and/or X & O. Measure and record overall lengths of both links. 2. Remove pitch links. 3. R66 Service Letter SL-20 refers. Disassemble pitch links, keeping parts from each link separate from the other. 4. Evaluate rod ends per § 5-33 and replace as required. 5. Visually inspect parts with 10X magnification for obvious damage. Replace damaged parts. 6. Visually inspect interior of barrels with borescope for obvious damage. Replace damaged barrels. 7. Apply a light coat of A257-2 or -22 oil to rod end threads and assemble pitch links; adjust to recorded lengths. Torque jam nut & adjacent palnut per § 20-32. Special torque self-locking 21FKF-813 jam nut per § 20-33. 8. Install pitch links to associated swashplate ear and, if installed, main rotor blade. Torque fasteners per § 20-32 and torque stripe per Figure 5-1. ROBINSON MAINTENANCE MANUAL MODEL R66 JUL 2020 Chapter 5 Inspections Page 5.39B 5-52 Swashplate Assembly 12-Year Inspection 1. Remove swashplate assembly per § 67-40. 2. Remove both pitch links and upper A205-7 fork assembly from swashplate. 3. Determine revision (“REV”) letters on C017-6 swashplate data plate. If revision letters are “AD” or subsequent, proceed to step 2. If revision letters are “AA”, “AB”, or “AC”, perform R66 Service Bulletin SB-30. 4. Refer to Figure 12-7. Remove (10) NAS1352 screws (with washers) securing C206-2 & C200-3 retainers to upper swashplate. Remove both retainers and C219-3 spacer and set aside. 5. Remove inner screws securing sleeve to lower swashplate. Remove sleeve, shims, and ball and set aside. 6. Using a 0.006 inch feeler gage, gently pry up outer edge of upper C217-1 seal and expose top ball bearing. Discard upper seal. 7. Clean all parts, including C203-5 yokes. 8. Visually inspect cleaned parts with 10X magnification, to include blind screw-holes in upper & lower swashplates, for obvious damage. Replace swashplate assembly if damage is detected on either upper or lower swashplate. Replace damaged parts. 9. Perform swashplate tilting friction adjustment per § 67-41 step 4. 10. Lubricate swashplate bearings per § 12-90 steps 7 thru 11. Install new upper seal during procedure. 11. Remove rod end form upper fork. Using non-metallic tools, remove majority of sealant in threaded hole of fork. Visually inspect parts with 10X magnification for obvious damage. Replace damaged parts. Assemble upper fork assembly and adjust pivots’ center-to-center dimension to 3.85±0.03 inches. Standard torque jam nut & palnut per § 20-32 and torque stripe per Figure 5-1. Fill exposed cavity with B270-13 sealant. 12. Remove lower A205-7 fork assembly from non-rotating scissors and clean. Remove rod end from lower fork. Visually inspect parts with 10X magnification for obvious damage. Replace damaged parts. Assemble lower fork assembly and adjust pivots’ center-to-center dimension to 3.70±0.03 inches. Standard torque jam nut