Bell Helicopter model 206L4. MAINTENANCE MANUAL (GENERAL INFORMATION)

BHT-206L4-MM-1

SPECIAL INSPECTIONS

5-45.

1 TO 5 HOURS AFTER EACH INSTALLATION

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

MAIN ROTOR

Chapter 62

Torque check main rotor mast nut 250 to 275 foot-pounds

(339.0 to

372 Nm) until the torque is stabilized

(TB 206L-07-223).

10 MAR 2017

Rev. 22

Page 131/132

Export Classification C,

BHT-206L4-MM-1

SPECIAL INSPECTIONS

5-46.

3 TO 8 HOURS AFTER EACH INSTALLATION

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

MAIN ROTOR

BHT-206L-CR&O

Torque check pillow block retention bolts/nuts

84 to

107

inch-pounds (9.4 to 12 Nm).

Check for misalignment of anti-slippage marks.

7 NOV 2014

Rev. 20

Page 133/134

Export Classification C,

BHT-206L4-MM-1

SPECIAL INSPECTIONS

5-47.

10 TO 25 HOURS AFTER EACH INSTALLATION

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

SWASHPLATE ASSEMBLY

Chapter 62

Check swashplate tilt friction. Value must be between 15 to

32 pounds (67 to 142 N). If not within limits, adjust to 15 to

32 pounds (67 to 142 N). Check tilt friction every 10 to 25 hours

until it is stabilized.

Chapter 65

DISC PACK COUPLING

Torque check disc pack coupling attaching hardware as follows:

Apply the minimum torque required for the fasteners. If the

fasteners do not move, the check is completed. Check torque

seal (C-049) and apply as required.

If the fastener(s) moved, do the steps that follow:

a. Remove the affected disc pack coupling and examine

the bolts, nuts (minimum tare torque, refer to BHT-ALL-SPM)

and washer for condition. Discard damaged parts.

b. Examine the disc pack coupling for condition. Discard

damaged disc pack coupling.

c. Install the removed disc pack coupling and repeat

torque check after 10 to 25 hours, until the torque is stabilized.

Re-apply torque seal (C-049) as required.

Export Classification C,

10 MAR 2017

Rev. 22

Page 135

BHT-206L4-MM-1

SPECIAL INSPECTIONS

5-48.

100 HOURS AFTER EACH INSTALLATION

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

POWER PLANT

Chapter 71

Torque check engine mount attachment hardware at

engine and airframe attachment points.

If fastener is improperly torqued:

a. Check nuts tare torque, and bolt threads and shanks for

damage.

b. Check engine mounts and supporting structure for

damage.

c. Install new fastener if required, and apply torque.

Recheck torque at next 100 hours.

TAILBOOM

Chapter 53

Torque check tailboom attachment nuts 375 to 415 inch-pounds

(42.4 to 46.8 Nm).

TRANSMISSION

Chapter 63

Replace oil filter element and oil. Inspect removed element

for metal particles. If particles are found, investigate to

determine cause.

Page 137

BHT-206L4-MM-1

SPECIAL INSPECTIONS

5-48.

100 HOURS AFTER EACH INSTALLATION (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

NOTE

If a nut is improperly torqued, remove and check tare

torque, and replace as required. Recheck torque at

next 100 hours.

Torque check transmission top case stud nuts 130 to 160

inch-pounds (15 to 18 Nm).

BHT-ALL-SPM

Touch up paint finish as required.

Page 138

BHT-206L4-MM-1

SPECIAL INSPECTIONS

5-48A. FREEWHEEL LUBRICATION SYSTEM

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

This special inspection is required to ensure that there is no

debris or blockage of restrictors

406-040-263-101 and

406-040-264-101 located on the left side of the forward engine

firewall. Blockage of the restrictor could cause the freewheel

assembly to malfunction.

FREEWHELL OIL SUPPLY SYSTEM FILTER (50-075-1) AND

RESTRICTORS (406-040-263-101 AND 406-040-264-101).

WARNING

THE FREEWHEEL OIL SUPPLY SYSTEM

INSPECTION MUST BE DONE AFTER ANY OF

THE FOLLOWING EVENTS:

• Anytime the freewheel oil supply is opened upstream of

the restrictor.

• The disconnection, replacement, or reconnection of any

fitting, hose or component between restrictors

406-040-263-101 and

406-040-264-101, and filter

50-075-1.

Chapter 63

Do the inspection for the following:

ASB 206-14-174

31 AUG 2021

Rev. 25

Page 138A

Export Classification C,

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-49. CONDITIONAL INSPECTIONS

• Overspeed — Main rotor — 114% or greater

Accomplish the applicable conditional inspections

• Overtorque

(paragraph

5-50 through paragraph

5-57) of the

helicopter after the following:

• Engine compressor stall or surge

• Hard landing

• Lightning strike

• Sudden stoppage/acceleration — Main rotor

• Engine overtemp

• Sudden stoppage/acceleration — Tail rotor

Page 139/140

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-50. HARD LANDING

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

HARD LANDING

A hard landing is defined as any incident in which the impact of

the helicopter with the ground causes severe pitching of the

main rotor. Blades involved in this type of hard landing must be

thoroughly inspected visually. If no obvious damage is

discovered, the blades may be retained in service for continued

usage.

If, on a hard landing, either main rotor blade comes in contact

with the ground, tailboom, or other foreign object, both main

rotor blades are to be regarded as having been involved in a

sudden stoppage and must be returned to a Bell Helicopter

Textron approved blade repair station for inspection.

The airframe landing skids and crosstubes will deform and yield

under load forces in excess of 2.5 G's. If the cabin fuselage

contacts the ground, the G forces in the fuselage increase

abruptly. If, following a hard landing, the cabin fuselage is

resting on the ground or shows evidence of having touched the

ground, it is considered to have sustained a 10 G load.

If on a hard landing the shear pin in the elevator control tube

(206-001-098) is sheared, the eyebolt

(206-001-902) that

retains the elevator control tube (206-001-098) to torque tube

(206-001-306) must be replaced as well as the elevator control

tube (206-001-098).

Page 141

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-50. HARD LANDING (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

NOTE

Components removed from helicopter for evaluation

following a hard landing shall be evaluated as an

interrelated group. Removal records accompanying

each component shall cross-reference part and

serial numbers of other drive system components

removed for evaluation.

Inspect landing gear skid tubes and crosstubes for damage

and deflection.

Inspect crosstube attachment points on the fuselage for

damage or distortion.

Check all cowling, fairing, and doors for proper fit and

alignment. Misaligned cowling, fairing, or doors may indicate a

distorted fuselage, resulting in major stresses and damage to

components.

Remove all cowlings and fairings necessary to perform a

complete visual inspection.

Rolls-Royce 250-C30

Engine. Refer to the Rolls-Royce Maintenance Manual for

Series Operation and

inspection instructions.

Maintenance Manual,

14W2

Check for leaks in the hydraulic system, interference or

binding of hydraulic actuator and controls, and for satisfactory

operation.

Perform complete visual inspection of the flight control

system from pilot controls to main rotor head and check for bent

or damaged tubes, bellcranks, and supports. Particular attention

should be given to the pitch link assemblies swaged ends for

cracks and to swashplate pivot sleeve at the lever attachment

points for damage.

Page 142

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-50. HARD LANDING (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

a. Remove and inspect suspected control tube for

straightness by rolling on a surface plate or with use of a metal

straight edge. On fixed control tubes the swaged end must be

concentric to tube within 0.06 inch (1.5 mm) Total Indicated

Runout (TIR). Scrap damaged control tube. If no damage is

found, reinstall control tube.

BHT-206L-CR&O

b. If visual inspection reveals damage to the swashplate

and support assembly, accomplish the following:

(1) Overhaul swashplate and support assembly.

(2) Accomplish an overhaul of main rotor hub

assembly in accordance with the Conditional Inspection criteria.

(3) Overhaul drive collar, link, and lever.

(4) Overhaul all connecting control tubes and scrap all

connecting control bolts.

BHT-ALL-SPM

c. Inspect all bearings for smoothness and axial and radial

play.

Inspect structure with a 10X magnifying glass around the

transmission mounting points. Particular attention should be

given to the transmission restraint system and transmission

mount stops for sheared bolts, damaged drag pins, and

supports.

lnspect transmission pylon link assemblies for contact with

nodal beam up stop and bolt head.

10. lnspect surrounding structure for contact with main

driveshaft.

11. lnspect cabin roof shell and beam supporting the

transmission mount support assemblies for cracks or

deformation.

12. lnspect transmission up and down stops for deformation

and loss of attachment nut torque.

13. lnspect the transmission restraint and stop mounts for

damage.

Export Classification C,

7 JUN 2013

Rev. 18

Page 143

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-50. HARD LANDING (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

14. If one or more of the inspection requirements in step 9

through step 13 reveals an unsatisfactory condition, a mast run

out inspection must be performed.

BHT-206L-CR&O

15. If damage in any of the inspection requirements of step 9

through step 14 is noted, the main rotor hub assembly must be

overhauled in accordance with the Conditional Inspection

criteria.

16. Inspect mast for indentions caused by static stop(s). If

mast is damaged from an excessively hard contact with main

rotor static stop, scrap mast pole. Remove and overhaul the

following components to ensure airworthiness:

a. Main rotor hub assembly in accordance with the

Conditional Inspection criteria.

b. Transmission assembly.

c. Main driveshaft assembly. Remove and examine the

driveshaft for deformation and cracks. If deformation or cracks

are found, discard the driveshaft.

d. Transmission restraint.

e. Remove main rotor blades and send to a Bell Helicopter

Textron approved blade repair facility for evaluation.

17. lnspect engine mounts at fuselage attachment points for

cracks.

18. lnspect tailboom for contact with main rotor blades. If

damage is found, accomplish main rotor sudden stoppage

inspection.

19. lnspect oil cooler blower shaft for straightness, and impeller

and shaft assembly for balance.

20. lnspect tail rotor blades for damage. If damage is found,

accomplish tail rotor sudden stoppage inspection.

Page 144

Rev. 18

7 JUN 2013

Export Classification C,

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-50. HARD LANDING (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

21. Inspect tail skid tube and mounting for damage. Inspect

tailboom internally and externally for cracks, distortion, and

sheared or loose rivets. Inspect the tailboom attachment points

for elongated bolt holes and damaged structure.

22. lnspect fuel and oil systems for damage. During

ground-run, check fuel and oil systems for leaks.

BHT-206L-CR&O

23. If damage to fuselage structure or tailboom is such that a

major repair alignment in a fixture is required, or if landing gear

crosstubes permanent set exceeds limits, remove and overhaul

the following components:

a. Main rotor hub assembly in accordance with the

Conditional Inspection criteria.

b. Swashplate and support assembly, with drive collar,

link, and lever.

c. All control tubes.

d. Main rotor pitch link assemblies.

e. Transmission and mast assembly.

f. Freewheel assembly.

g. Tail rotor driveshaft assembly.

h. Tail rotor gearbox.

i. Tail rotor hub and blade assembly.

j. Transmission restraint and mount systems.

k. Remove main rotor blades and send to a Bell Helicopter

Textron approved blade repair facility for evaluation.

l. Replace all control bolts from hydraulic servo actuator

to the main rotor hub.

m. Main driveshaft must be considered unserviceable and

scrapped.

Export Classification C,

7 JUN 2013

Rev. 18

Page 145

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-51. SUDDEN STOPPAGE/ACCELERATION — MAIN ROTOR

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

SUDDEN STOPPAGE/ACCELERATION

Sudden stoppage/acceleration is defined as any rapid

deceleration or acceleration of the drive system whether caused

by seizure within the drive system, sudden freewheel clutch

engagement, or impact of the main rotor with the ground or with

a foreign object of sufficient inertia to cause rapid deceleration.

NOTE

Components removed from helicopter for evaluation

following a sudden stoppage/acceleration shall be

evaluated as an interrelated group. Removal records

accompanying

each

component

shall

cross-reference part and serial numbers of other

drive system components removed for evaluation.

After sudden stoppage, inspect main rotor blades as

follows:

a. Remove tip cover plate from both main rotor blades.

b. Inspect blade skin and bonded doublers for visible

damage.

c. Check tip weights. If any movement of tip weights has

occurred, blade shall be scrapped.

Page 147

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-51. SUDDEN STOPPAGE/ACCELERATION — MAIN ROTOR (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

After sudden stoppage of the main rotor, remove both main

rotor blades. Send blades to a Bell Helicopter Textron approved

blade repair facility for evaluation.

Remove the following components and visually inspect for

evidence of torsional yielding, deformation, cracks, or other

obvious damage that would render them non-repairable.

Conduct an overhaul of these components.

NOTE

If main rotor mast was severed during main rotor

sudden stoppage/acceleration, the main rotor hub

assembly must be considered unserviceable and

scrapped.

BHT-206L-CR&O

a. Main rotor hub assembly in accordance with the

Conditional Inspection criteria.

NOTE

If main rotor mast was severed during a main rotor

sudden stoppage/acceleration with the engine

operating, the main rotor mast has sustained

torsional yielding.

b. Mast assembly.

BHT-206A/B/L-Series-

(1) Concurrently with mast assembly overhaul,

CR&O

accomplish the following inspections:

(a) Do a Total Indicated Runout (TIR) of the main

rotor mast.

Page 148

Rev. 18

7 JUN 2013

Export Classification C,

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-51. SUDDEN STOPPAGE/ACCELERATION — MAIN ROTOR (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

CAUTION

IF MAIN ROTOR MAST HAS EVIDENCE OF

TORSIONAL YIELDING, THE MAST ASSEMBLY,

TRANSMISSION ASSEMBLY, MAIN DRIVESHAFT,

AND FREEWHEEL ASSEMBLY (OUTER RACE,

INNER RACE, AND CLUTCH) SHALL BE

CONSIDERED UNSERVICEABLE AND

SCRAPPED. MAJOR DAMAGE TO THE MAST

ASSEMBLY OTHER THAN TORSIONAL YIELDING

REQUIRES REPLACEMENT OF TRANSMISSION

TOP CASE. IF TRANSMISSION TOP CASE HAS

TO BE SCRAPPED, PYLON MOUNT SPINDLES

AND MAST BEARINGS SHALL ALSO BE

SCRAPPED.

(b) Torsional yielding may be detected by

measuring the offset between the mast splines above and

below the main rotor trunnion split cone groove using either of

the following methods:

Sliding a

0.1600 inch

(4.06 mm)

diameter measuring pin across the upper and lower spline.

ii.

Sliding a straight edge across the upper

and lower unworn face of the spline (coast side of the spline).

BHT-206L-CR&O

c. Transmission assembly.

d. Swashplate assembly.

NOTE

Replace all control bolts from hydraulic servo

actuators to main rotor hub.

e. All cyclic and collective control tubes from mixing lever

to swashplate.

f. Main rotor pitch link assemblies.

g. Freewheel assembly.

Export Classification C,

7 JUN 2013

Rev. 18

Page 149

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-51. SUDDEN STOPPAGE/ACCELERATION — MAIN ROTOR (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

BHT-206L-CR&O

h. Main driveshaft must be considered unserviceable and

scrapped.

i. lnspect transmission restraint and transmission mount

system for condition, and fuselage attachment points for cracks.

j. lnspect engine mounts at fuselage attachment points for

cracks.

NOTE

If a tail rotor driveshaft failed as a result of torsional

overload, ALL hangers, driveshafts, adapters,

impellers, and disc couplings shall be considered

unserviceable and scrapped. Inspect hanger

attachment points for cracks and distortion. Overhaul

tail rotor gearbox to ensure airworthiness.

If a tail rotor driveshaft has been damaged by main

rotor strike or damage other than torsional overload,

ALL bonded tail rotor driveshafts, plus the hanger

assemblies, adapters, and disc couplings

fore-and-aft of the damaged area shall be considered

unserviceable and scrapped. Inspect remaining

hanger assemblies, adapters, and disc couplings

according to step l and step m. Inspect hanger

attachment points for cracks and distortion.

k. Inspect tail rotor driveshafts for out of roundness, and

distortion or bowing exceeding the limits specified. If any defect

is detected, scrap all bonded tail rotor driveshafts.

l. lnspect steel tail rotor driveshaft and all steel adapters

for cracks using magnetic particle inspection method.

m. Inspect tail rotor driveshaft hangers, disc couplings, and

aluminum driveshaft adapters using fluorescent penetrant

inspection method.

In addition to step l, step m, and related notes, all bonded

tail rotor driveshafts shall be considered unserviceable and

scrapped, if during a sudden stoppage/acceleration inspection

any of the following conditions that are attributable to the

sudden stoppage/acceleration are noted:

Page 150

Rev. 16

1 JUN 2012

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-51. SUDDEN STOPPAGE/ACCELERATION — MAIN ROTOR (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

a. Any impact damage to a main rotor blade leading edge

or lower skin, or any main rotor blade skin buckling or tears.

b. If main rotor mast is sheared, power on or off, or with

torsional yielding, or TIR check exceed limits.

c. Any deformation of any coupling disc that results in

gaps between laminates greater than 0.015 inch (0.381 mm).

d. Structural failure or distortion of any coupling disc bolts.

e. Structural failure, or distortion exceeding the specified

limits of the tail rotor driveshaft steel or aluminum adapters.

Rolls-Royce 250-C30

Refer to the Rolls-Royce 250-C30 Series Operation and

Series Operation and

Maintenance Manual, 14W2 for sudden stoppage inspection

Maintenance Manual,

requirements.

14W2

Page 151/152

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-52. SUDDEN STOPPAGE/ACCELERATION — TAIL ROTOR

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

SUDDEN STOPPAGE/ACCELERATION

BHT-ALL-SPM

Sudden stoppage is defined as any rapid deceleration or

acceleration of the drive system whether caused by seizure

within the helicopter drive system, sudden freewheel clutch

engagement, or by contact of tail rotor blade(s) with the ground,

water, or with a foreign object of sufficient inertia to cause rapid

deceleration.

CAUTION

DAMAGE TO TAIL ROTOR BLADE ASSEMBLY

COULD BE PRESENT ALTHOUGH IT MAY NOT BE

READILY DETECTED BY STANDARD VISUAL,

DIMENSIONAL, AND MAGNETIC PARTICLE OR

FLUORESCENT PENETRANT INSPECTION

METHODS.

NOTE

Components removed from helicopter for evaluation

following a sudden stoppage/acceleration shall be

evaluated as an interrelated group. Removal records

accompanying

each

component

shall

cross-reference part and serial numbers of other

drive system components removed for evaluation.

Remove and scrap tail rotor hub and blade assembly.

Page 153

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-52. SUDDEN STOPPAGE/ACCELERATION — TAIL ROTOR (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

Overhaul the following components:

a. Tail rotor gearbox assembly.

b. Freewheel assembly.

c. Tail rotor pitch change mechanism.

BHT-ALL-SPM

Inspect all tail rotor driveshafts, impeller, steel and

BHT-206L-CR&O

aluminum adapters, flexible coupling discs, and hangers using

magnetic particle or fluorescent penetrant methods, whichever

is applicable.

Visually inspect shafts for evidence of twisting, and check

for out of round and Total Indicated Runout (TIR) exceeding

specified limits. Inspect the bonds between the tail rotor

driveshaft and bonded adapter for integrity. If any defect is

detected, scrap all bonded tail rotor driveshafts.

lnspect tail rotor hanger support at tailboom and fuselage

attachment points for cracks.

lnspect tail rotor hanger supports for cracks and distortion.

BHT-206L-CR&O

NOTE

If tail rotor driveshaft failed as a result of torsional

overload, ALL hangers, driveshafts, adapters,

impeller, and disc couplings shall be considered

unserviceable and scrapped. Inspect hanger

attachment points for cracks and distortion. Ensure

airworthiness of tail rotor gearbox by conducting a

major overhaul.

If a tail rotor driveshaft has been damaged by main

rotor strike or damage other than torsional overload,

ALL bonded tail rotor driveshafts, plus the hanger

assemblies, adapter, and disc couplings fore and aft

of the damaged area shall be considered

unserviceable and scrapped. Inspect remaining

hanger assemblies, adapters, and disc couplings

using the magnetic particle or fluorescent penetrant

inspection, whichever is applicable, for cracks and

distortion.

Page 154

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-52. SUDDEN STOPPAGE/ACCELERATION — TAIL ROTOR (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

In addition ALL bonded tail rotor driveshafts shall be

considered unserviceable and scrapped, if during a sudden

stoppage inspection any of the following conditions that are

attributable to the sudden stoppage are noted:

a. Any impact damage to a tail rotor blade leading edge or

skin, or any tail rotor blade skin buckling or tearing.

b. Any deformation of any coupling discs that result in

gaps between laminates greater than 0.015 inch (0.381 mm).

c. Structural failure or distortion of any coupling disc bolts.

d. Structural failure or distortion exceeding the specified

limits of the tail rotor driveshaft steel or aluminum adapters.

lnspect tailboom area of tail rotor gearbox mounting studs

and dowel pins for cracks using a 10X magnifying glass or

fluorescent penetrant method of inspection.

Inspect the four tailboom attachment points for cracks,

distortion damage, and security. Check torque on nuts of

tailboom attachment bolts.

10. lnspect tailboom internally for cracks, distortion, and loose

or missing rivets. Check external skin of tailboom for cracks

paying particular attention to area of horizontal stabilizer and

attachment points of vertical fin.

11. Inspect horizontal stabilizer and finlets for cracks and

overall condition.

BHT-206L-CR&O

12. Inspect vertical fin for security and overall condition. Check

tail skid for condition and security. Check mounting of

anticollision light for security and condition.

Rolls-Royce 250-C30

13. Refer to the Rolls-Royce 250-C30 Series Operation and

Series Operation and

Maintenance Manual, 14W2 for sudden stoppage inspection

Maintenance Manual,

requirements.

14W2

Page 155/156

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-53. OVERSPEED MAIN ROTOR — 114% OR GREATER

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

OVERSPEED MAIN ROTOR — 114% OR GREATER

NOTE

Components removed from a helicopter for

evaluation following an overspeed shall be evaluated

as an interrelated group. Removal records

accompanying

each

component

shall

cross-reference part and serial numbers of other

drive system components removed for evaluation.

For main rotor overspeeds above 107% and up to

114%, visually inspect main rotor blades and tail rotor

blades for skin wrinkles or damage. If damage or

wrinkles are detected, accomplish complete

overspeed inspection.

If the main rotor overspeeds in excess of 114% RPM,

proceed with the following:

a. Discarding of the following items is mandatory:

(1) Tension/torsion straps.

(2) Inboard strap fittings and pins.

(3) Latch bolts.

b. Main rotor blades.

Export Classification C,

7 JUN 2013

Rev. 18

Page 157

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-53. OVERSPEED MAIN ROTOR — 114% OR GREATER (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

(1) Dimensionally check main rotor blade retention

bolt hole for indications of permanent deformation or damage. If

inside diameter of bushing in the hole is elongated in excess of

0.0015 inch (0.0381 mm), remove blade from service and return

it to a Bell Helicopter Textron approved major overhaul facility

for further inspection. Any evident looseness of bushing is

cause for scrapping blade.

(2) Remove tip cap assembly from main rotor blade

and inspect tip cap attaching screws for deformation. Any

deformation of screws or elongation of mating holes in the spar

is cause for scrapping blade.

(3) Visually inspect main rotor blade for skin wrinkles

or deformation. If any indication of wrinkles or deformation

exists, return blade to a Bell Helicopter Textron approved major

overhaul facility for evaluation.

(4) If main rotor blades pass the previous inspection,

they are acceptable for continued service.

c. Tail rotor blades.

(1) If one of the tail rotor blades of a pair has been

damaged badly enough that metal has been torn or any bond

plies have separated, then both blades and tail rotor hub must

be scrapped.

(2) If contour of a blade has been damaged slightly

(distortion) then both blades and tail rotor hub must be

scrapped.

(3) If any movement of the tip block or root end

balance weights has occurred, scrap tail rotor hub assembly

and both tail rotor blades.

(4) If tip block is cracked, scrap tail rotor hub assembly

and both tail rotor blades.

(5) If tail rotor blades pass the above inspection

requirements and no other discrepancies exist, the blades are

acceptable for continued service.

Page 158

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-53. OVERSPEED MAIN ROTOR — 114% OR GREATER (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

BHT-206L-CR&O

d. Overhaul the main rotor hub assembly in accordance

with the Conditional Inspection criteria.

BHT-206A/B/L-Series-

e. Overhaul the tail rotor hub assembly.

CR&O, Chapter 64

BHT-ALL-SPM

f. Inspect oil cooler fan impeller for visible distortion or

cracks of the brazed vane joints using dye penetrant inspection

method.

Rolls-Royce 250-C30

Engine. Refer to the Rolls-Royce

250-C30 Series

Series Operation and

Operation and Maintenance Manual, 14W2.

Maintenance Manual,

14W2

7 JUN 2013

Rev. 18

Page 159/160

Export Classification C,

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-54. OVERTORQUE

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

DATE: __________________W.O. _____________________

FACILITY: _________________________________________

HELICOPTER S/N: __________________________________

REGISTRY NO.: ____________________________________

TOTAL TIME:_______________________________________

SIGNATURE:_______________________________________

NOTE

Torque Indicator Reference:

100% = 71.4 PSI,

110% = 78.5 PSI, 120% = 85.7 PSI.

OVERTORQUE — 110 TO 120%

NOTE

Components removed from a helicopter for

evaluation following an overtorque shall be evaluated

as an interrelated group. Removal records

accompanying

each

component

shall

cross-reference part and serial numbers of other

drive system components removed for evaluation.

NOTE

If overtorque above 100% up to 110% should occur,

no inspection is required.

If overtorque above

110% up to 120% should occur,

perform the following:

a. Conduct a visual inspection of the following listed

assemblies (installed on the helicopter) for any evidence of

damage, deformation, yielding, etc.

Page 161

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-54. OVERTORQUE (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

(1) Main rotor blades and attachments. Blade for skin

wrinkles and bond separation. If any indications of wrinkles or

deformation exists, send blades to a Bell Helicopter Textron

approved blade repair facility for evaluation.

(2) Main rotor hub assembly.

(3) Transmission top case.

(4) Transmission mount fittings at upper attachment

points and lower stop mounts.

(5) Cabin roof and beam at transmission restraint

support assembly attachment points.

(6) Cabin roof and beam at nodal beam support

attachment points.

(7) Tail rotor hub, blades, and attachments.

b. Examine the transmission electric chip detectors for

accumulated material.

c. Remove and examine the engine-to-transmission

driveshaft for deformation and cracks. If deformation, cracks, or

other damage is found, discard the driveshaft.

CAUTION

A QUALIFIED PERSON MUST BE AT THE

HELICOPTER CONTROLS DURING THE

FOLLOWING PROCEDURE.

BHT-206L4-FM-1

d. Start engine and check main rotor, while in a flat pitch

condition, for any evidence of a

1/rev vibration or lateral

vibration.

BHT-206A/B/L-Series-

e. If one or more of the previous inspection requirements,

CR&O, Chapter 63

step a through step d, reveals an unsatisfactory condition, a

mast runout inspection shall be performed.

Page 162

Rev. 18

7 JUN 2013

Export Classification C,

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-54. OVERTORQUE (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

Rolls-Royce 250-C30

Refer to the Rolls-Royce 250-C30 Series Operational and

Series Operation and

Maintenance Manual for applicable inspection.

Maintenance Manual,

14W2

After the first 25 hours following an overtorque, conduct a

thorough visual inspection of the following:

a. Main rotor blades and attachments.

b. Main rotor hub assembly.

c. Main rotor mast.

d. Transmission top case.

e. Transmission mount link assemblies, link attachments,

and arm and support assemblies.

f. Cabin roof shell and beam at transmission mount

attachment points.

g. Transmission restraint attachment at stop mounts,

support, and cabin roof shell and beam.

h. Transmission electric chip detectors.

i. Tail rotor gearbox chip detector and gearbox

attachments.

j. Tail rotor hub, blades, and attachments.

OVERTORQUE — ABOVE 120%

NOTE

Components removed from helicopter for evaluation

following an overtorque shall be evaluated as an

interrelated group. Removal records accompanying

each component shall cross-reference part and

serial numbers of other drive system components

removed for evaluation.

Page 163

BHT-206L4-MM-1

CONDITIONAL INSPECTIONS

5-54. OVERTORQUE (CONT)

INITIAL

DATA REFERENCE

INSPECTION TASK DESCRIPTION

MECH OTHER

NOTE

The overhaul inspection criteria in the specific

sections, including limit charts and other pertinent

information, should be used to establish that the

detail parts in each assembly are dimensionally

within limits and have not yielded or become

deformed.

If an overtorque above

120% occurs, accomplish all

inspections required for overtorque

— 110 to 120% and in

addition, conduct following inspection:

a. Main Rotor Hub. Remove and overhaul in accordance

with the conditional inspection criteria.

b. Main Rotor Mast. Remove and overhaul.

c. Main Transmission. Remove and overhaul. Replace top

case of main transmission and transmission link attachments.

During overhaul, inspect gear patterns for shifting and scuffing.

d. Main driveshaft. Remove and visually inspect.

e. Freewheel assembly. Remove and overhaul.

Rolls-Royce 250-C30

Refer to the Rolls-Royce 250-C30 Series Operation and

Series Operation and

Maintenance Manual, 14W2 for applicable inspection.

Maintenance Manual,

14W2

After the first 25 hours following an overtorque, conduct a

thorough visual inspection of the following:

a. Main rotor blades and attachments.

b. Main rotor hub assembly.

c. Main rotor mast.

d. Transmission top case.

Page 164

Rev. 18

7 JUN 2013

Export Classification C,

Bell Helicopter model 206L4. MAINTENANCE MANUAL (GENERAL INFORMATION) - page 5