ALERT SERVICE BULLETIN 407-12-98 24 October 2012 MODEL

ALERT SERVICE BULLETIN
407-12-98
24 October 2012
MODEL AFFECTED:
407
SUBJECT:
PLANETARY PINION GEAR P/N 406-040-095-101,
INSPECTION OF;
HELICOPTERS AFFECTED:
Serial numbers 53000 through 53900,
through 54106 and 54300 through 54346.
53911
[Serial numbers 54107 through 54299 and 54347 and
subsequent will have the intent of this bulletin
accomplished prior to delivery.]
COMPLIANCE:
PART I of this bulletin to be accomplished on spare
gears prior to installation into a serviceable
component, but no later than 31 December 2012
PART II of this bulletin to be accomplished on installed
gears at next scheduled transmission overhaul.
DESCRIPTION:
Bell Helicopter has received reports of planetary pinion gear P/N 406-040-095-101 with
cracks located in the roller guide flange. Cracks are due to an improperly performed
machining operation and associated stresses induced during manufacturing.
This bulletin is issued to owners/operators of the model 407 to highlight a specific area
of the gear where cracks were found and require performing a one-time Magnetic
Particle Inspection (MPI) on all spare gears with serial number prior to A-FS14691
before installation. Affected gears currently installed shall have an MPI accomplished at
the next overhaul in accordance with the BHT-407-CR&O. Pinion gear serial numbers
A-FS14691 and subsequent are not affected by this bulletin.
APPROVAL:
The engineering design aspects of this bulletin are Transport Canada Civil Aviation
(TCCA) approved.
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CONTACT INFO:
For any questions regarding this bulletin, please contact:
Bell Helicopter Product Support Engineering - Light Helicopters
Tel: 450-437-2862 / 1-800-363-8023 / [email protected]
MANPOWER:
Approximately 1.0 man-hour is required to complete PART I of this bulletin. No
additional man-hours are required to accomplish PART II of this bulletin when done in
conjunction with the scheduled transmission overhaul.
This estimate is based on hands-on time, and may vary with personnel and facilities
available.
WARRANTY:
Owners / Operators of Bell Helicopters who comply with the instructions in this bulletin
will be eligible to receive a pro-rated credit for the replacement gear over 10,000 hrs.
To receive this credit:




Comply with the instructions contained in this bulletin no later than the applicable
date in the “Compliance Section” of this ASB.
Purchase replacement parts as required from a Bell approved source.
Submit an MMIR to the Bell Warranty Department referring to this bulletin.
If the performance of an MPI is not practical or currently possible, return spare
(new) affected part to Bell and submit an MMIR to the Bell Warranty Department
for replacement, indicating that the MPI could not be performed as required by
this bulletin.
Customers who fail to comply with the instructions in this bulletin before the compliance
date are not eligible for the special warranty credit listed above. There is no labor
associated with this bulletin.
MATERIAL:
Required Material:
The following material may be required for the accomplishment of this bulletin if a
discrepant part is found.
Part Number
Nomenclature
Qty
406-040-095-101
Planetary Pinion Gear
A/R
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Consumable Material:
None required.
SPECIAL TOOLS:
None required.
WEIGHT AND BALANCE:
Not affected.
ELECTRICAL LOAD DATA:
Not affected.
REFERENCES:
BHT-407-MM Maintenance Manual
BHT-407-CR&O Component Repair and Overhaul Manual
PUBLICATIONS AFFECTED:
None affected.
ACCOMPLISHMENT INSTRUCTIONS:
PART I
1. For affected pinion gears consigned in spare stock, perform a Magnetic Particle
Inspection (MPI) of the gear in accordance with the BHT-407-CR&O, Chapter 63,
Table 63-11, for pinion gear P/N 406-040-095.
a. Pay particular attention to the area specified in Figure 1.
2. If a cracked gear is found, submit an MMIR to the Bell Warranty Department.
3. If no cracks are found, the gear can be returned to stock. Make an entry in
component historical record, or on a new release certificate (or other acceptable
method of documentation) to show compliance with this bulletin.
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PART II
1. For affected pinion gears installed in a transmission, perform a Magnetic Particle
Inspection (MPI) of the gear in accordance with the BHT-407-CR&O Table 63-11 at
overhaul as indicated in the component overhaul schedule for the transmission.
a. Pay particular attention to the area specified in Figure 1.
2. If a cracked gear is found, submit a MMIR to the Bell Warranty Department.
3. Make an entry in the helicopter logbook and component historical service records
indicating compliance with this bulletin.
NOTE: The white lines on the inner ID of the gear represent the crack location.
Figure 1- 406-040-095-101 Pinion Gear.
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