Summary of the Problem. - TB-1-1520-237-20-2220002

TB 1--1520--237--20--222

Maintenance Trainers (Category A, and B). Same as para 1a.

f. Component/Parts in Stock at All Levels (Depot and Others), Including War Reserves. Upon receipt

of this TB, Depot and Material Activity Commanders will ensure the material condition tags of all items in all

condition codes listed in paragraph 6 are annotated to read "TB 1--1520--237--20--222, Inspection of the Input

Module Gearbox Assembly Not Complied With".

(1) Wholesale Stock. Report receipt of this TB IAW Paragraph 14c(1). Upon receipt of this TB,

Depot and Material Activity Commanders will ensure all serviceable items (Condition Code //A//, //B//, //C//,

//D//, and //E// listed in paragraph 6 are placed in condition code //J// and tagged with a Suspended Tag/Label,

Material, DD Form 1575/DD Form 1575--1. Do not remove original condition tags.

(2) Retail Stock. Report receipt of this TB IAW paragraph 14c(2). Upon receipt of this TB, Com-

manders and Facility Managers maintaining retail stock at installation level and below shall contact the sup-

ported aviation unit to perform the procedures required IAW paragraphs 8 and 9 on suspect material. Dispose

of discrepant material IAW paragraph 10. Report compliance with this message IAW paragraph 14d(2).

Components/Parts in Work (Depot Level and Others). N/A

2. Task/Inspection Suspense Date. Complete the inspection IAW paragraph 8 prior to the next flight but

NLT16 August 2000 and report IAW para 14b.

Reporting Compliance Suspense Date. Report compliance IAW para 14a NLT 23 August 2000.

Summary of the Problem.

a. There have been three failures of input module accessory drive bevel gears on H--60 aircraft. Failure

can cause loss of transmission lubricant, loss of NR signal, and accessory and input chiplights. Investigations

have shown that each of the failures were caused by a gear removal tool used during repair of the input mod-

ules at CCAD which resulted in fatigue crack propagation from a static crack in a gear tooth root. Although

the gear removal tool was not used on all input modules, its use was not documented. Therefore, all input

modules repaired at CCAD are considered suspect. Past failure data reveals minimal probability of failure

for input modules with more than 130 flight hours since last installed.

For manpower/downtime and funding impacts see para 12.

The purpose of this TB is to:

(1) Identify and remove from service all suspected input modules with less than 30.0 flight hours

time since last repaired.

(2) Provide flight restrictions to allow operation of input modules identified with 30.1 to 250.0

hours time since last repaired.

End Items to be inspected . All H--60 series aircraft.

Assembly Components to be Inspected.

NOMENCLATURE

PART NUMBER

NSN

Input Module Assy

70351--08001--045

1615--01--168--2984

Input Module Assy

70351--08001--046

1615--01--230--6218

Input Module Assy

70351--08001--049

1615--01--353--3825

Parts to be Inspected. NA

Inspection Procedures..

NOTE

The following inspection must be performed separately for each input module

a. For each input module, inspect the Helicopter Historical Records (DA Form 2408--16) to determine

the time since last installed.