Textron Bell 412 User Manual

BHT-412-MM-1
NOTICE
The instructions set forth in this manual, as supplemented or modified by Alert Service Bulletins (ASB) or
other directions issued by Bell Helicopter Textron Inc. and Airworthiness Directives (AD) issued by the
applicable regulatory agencies, shall be strictly followed.
Export Classification C, ECCN EAR99
REISSUE — 23 JUNE 1994
REVISION 27 — 25 SEPTEMBER 2018
COPYRIGHT NOTICE
COPYRIGHT
201
BELL
® HELICOPTER TEXTRON INC.
AND BELL HELICOPTER TEXTRON
CANADA LTD.
ALL RIGHTS RESERVED
MAINTENANCE MANUAL
VOLUME 1
GENERAL INFORMATION

Textron Bell 412 Specifications

General

Brand	Textron
Model	Bell 412
Category	Toy
Language	English

Summary

MAINTENANCE MANUAL VOLUME 1

WARNING

CUSTOMER SUPPORT AND SERVICES

SPARE PARTS WARRANTY

CHAPTER 4 — AIRWORTHINESS LIMITATIONS SCHEDULE

AIRWORTHINESS LIMITATIONS SCHEDULE

Schedule detailing mandatory maximum life for components with limited airworthiness life.

CHAPTER 4 — AIRWORTHINESS LIMITATIONS SCHEDULE (CONT)

MAIN ROTOR HUB (CONT)

MAIN ROTOR CONTROLS

PROPULSION AND DRIVE SYSTEM

PROPULSION AND DRIVE SYSTEM (CONT)

Details airworthiness limitations for various propulsion and drive system components.

LANDING GEAR

CHAPTER 5 — INSPECTIONS

INSPECTIONS

SCHEDULED INSPECTIONS

Details on scheduled inspections, including Part A and Part B.

SPECIAL INSPECTIONS

Procedures for special inspections required under specific circumstances.

CONDITIONAL INSPECTIONS

Procedures for conditional inspections triggered by specific events.

COMPONENT OVERHAUL SCHEDULE

5-1. GENERAL

5-2. INSPECTION REQUIREMENTS

5-3. CRASH DAMAGE

5-3C. INSPECTION AND OVERHAUL TOLERANCE

5-4. SCHEDULED INSPECTIONS

Part A

Inspect helicopter daily, and at 100, 1000, and 5000 hour intervals.

Part B

Inspect helicopter at 25, 300, 600, and 5000 hour intervals.

5-5. DAILY INSPECTION — PART A

LANDING GEAR SYSTEM

MAIN ROTOR BLADES

MAIN ROTOR HUB

ENGINE-TO-TRANSMISSION (MAIN) DRIVESHAFT

TRANSMISSION

TAIL ROTOR HUB AND BLADE ASSEMBLY

TAIL ROTOR DRIVESHAFT

INTERMEDIATE GEARBOX

TAIL ROTOR GEARBOX

FLIGHT CONTROLS

5-6. 100 HOUR/12 MONTH INSPECTION — PART A

MAIN ROTOR MAST

5-7. 1000 HOUR INSPECTION — PART A

SWASHPLATE AND SUPPORT ASSEMBLY — HUB AND SLEEVE ASSEMBLY

5-8. 5000 HOUR/5 YEAR INSPECTION — PART A

5-9. 25 HOUR/30 DAY INSPECTION — PART B

MAIN ROTOR TRANSMISSION

5-10. 300 HOUR/12 MONTH INSPECTION — PART B

5-11. 600 HOUR/12 MONTH INSPECTION — PART B

5-12. 5000 HOUR/5 YEAR INSPECTION — PART B

CHAPTER 63

5-13. SPECIAL INSPECTION

5-14. DAILY/10 HOUR INSPECTION, WHICHEVER OCCURS FIRST UNTIL 250 HOURS

5-15. BETWEEN 1 AND 5 FLIGHT HOURS AFTER MAIN ROTOR HUB INSTALLATION

MAIN ROTOR HUB

Torque checks for main rotor hub through bolts, cap bolts, and lower cone bolts.

5-15A. BETWEEN 1 AND 25 FLIGHT HOURS AFTER EXPANDABLE BLADE BOLT INSTALLATION

5-16. BETWEEN 5 AND 10 HOURS OF FLIGHT AFTER EACH INSTALLATION

5-17. EACH 25 HOURS FOR THE NEXT FOUR INSPECTIONS

TAIL ROTOR HANGER BEARINGS WITNESS MARKS

5-18. EACH 25 HOURS OF TAIL ROTOR OPERATION

TAIL ROTOR BLADE (212-010-750-ALL ONLY)

Clean and visually inspect tail rotor blades for damage.

5-19. 50 HOURS AFTER INSTALLATION OF COMPONENTS

5-20. 100 HOURS AFTER INSTALLATION OF TAILBOOM

5-21. EACH 100 HOURS OF COLLECTIVE LEVER OPERATION

COLLECTIVE LEVER 412-010-408-101/-105

Inspect collective lever for cracks using light and magnifying glass.

5-22. EACH 150 HOURS OF STARTER GENERATOR (200SG119Q) OPERATION

5-22A. EACH 300 HOURS OR 6 MONTHS OF EXPANDABLE BLADE BOLT OPERATION

EXPANDABLE BLADE BOLT (412-010-137-103)

Disassembly, cleaning, inspection, and reassembly of expandable blade bolt.

5-23. EACH 600 HOURS OF TAIL ROTOR DRIVESHAFT OPERATION OR 12 MONTHS

TAIL ROTOR DRIVESHAFT FLEXIBLE COUPLINGS

5-24. EACH 600 HOURS OF MAIN DRIVESHAFT OPERATION OR 12 MONTHS

5-25. EACH 1000 HOURS OF COMPONENT OPERATION

5-26. EACH 12 MONTHS OR 2500 LANDINGS OF AFT HIGH CROSSTUBE OPERATION

HIGH AFT CROSSTUBE ASSEMBLIES (412-050-011-ALL AND 412-050-045-ALL) DEFLECTION CHECK

Perform deflection check on aft crosstube assemblies.

HIGH AFT CROSSTUBE ASSEMBLIES (412-050-011-ALL AND 412-050-045-ALL) FLUORESCENT PENETRANT INSPECTION

Perform fluorescent penetrant inspection on aft crosstube assemblies.

5-27. EACH 24 MONTHS OF CONTROL BOLT OPERATION

FLIGHT CONTROL SYSTEM BOLTS

5-27A. EACH 24 MONTHS OF MAIN ROTOR MAST OPERATION

MAIN ROTOR MAST ASSEMBLY (412-040-366-SERIES AND 412-040-368-SERIES)

Remove, clean, and inspect main rotor mast upper splines for corrosion.

5-28. EACH 2500 HOURS OF MAIN ROTOR HUB ASSEMBLY OPERATION

MAIN ROTOR HUB ASSEMBLY (412-010-100-SERIES) AND 412-010-502-SERIES

Disassemble main rotor hub, inspect drive pins, flexures, spindles, horns, seats, and plates.

5-29. EACH 2500 HOURS OF MAIN ROTOR BLADE OPERATION

MAIN ROTOR BLADES (412-015-200/-300 SERIES)

5-30. EACH 2500 OR 3000 HOURS OF MAIN ROTOR MAST (412-040-366-109 AND SUBSEQUENT) OPERATION

MAIN ROTOR MAST (412-040-366-109, AND SUBSEQUENT)

Remove, place, and inspect main rotor mast assembly components.

5-31. EACH 2500 HOURS OF TAIL ROTOR DRIVE SYSTEM OPERATION

TAIL ROTOR DRIVESHAFT

5-32. EACH 3000 HOURS OF MAIN ROTOR MAST (412-040-366-103 AND -105) OPERATION

MAIN ROTOR MAST (412-040-366-103 AND 412-040-366-105)

Remove, place, and inspect main rotor mast assembly components.

5-33. EACH 3000 HOURS OF TRANSMISSION (412-040-002) OPERATION

TRANSMISSION (412-040-002)

Disassemble transmission, inspect spiral bevel gear retaining bolts and teeth.

5-34. EACH 3000 HOURS OF TRANSMISSION (412-040-004) OPERATION

MAIN TRANSMISSION (412-040-004)

Inspect rotor brake quill, transmission surfaces, and jet assemblies.

5-35. 3600 HOURS TOTAL AIRFRAME TIME AND EACH 300 HOURS/12 MONTHS INSPECTION

CONDITIONAL INSPECTIONS

5-36. CONDITIONAL INSPECTION

5-37. AFTER HARD LANDING

Inspection procedures after a hard landing incident.

5-38. SUDDEN STOPPAGE — POWER ON OR OFF

Inspection procedures following a sudden stoppage incident.

5-39. AFTER OVERSPEED

Inspection procedures after an overspeed incident.

5-40. AFTER OVERTORQUE

5-41. AFTER COMPRESSOR STALL OR SURGE

5-42. AFTER LIGHTNING STRIKES

5-43. AFTER ENGINE COMBINING GEARBOX CLUTCH NON-ENGAGEMENT, MISENGAGEMENT, OR IN-FLIGHT SLIPPAGE

TABLE 5-1. Component Overhaul Schedule

ROTORS

POWER TRAIN

POWER PLANT