Summary of the Problem. - TB-1-1520-240-20-1280002

TB 1-1520-240-20-128

(2) Ferry Status.

(a) Inspect at final destination within 10 flight hours or 14 days of arrival.

(b) Boeing will inspect DD 250 aircraft prior to those aircraft departing for ferry to final destina-

tion.

Maintenance Trainers (Category A and B). Comply no later than 12 JAN 01.

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

of this Technical Bulletin, Depot and Materiel Activity Commanders will ensure the materiel condition tags of

all items in all condition codes listed in paragraph 7 is annotated to read "CH--47--00--ASAM--08 (TB

1--1520--240--20--128), Inspection of Forward Yoke Shaft, Not Complied With".

(1) Wholesale Stock . N/A.

(2) Retail Stock. N/A.

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

2. Task/Inspection Suspense Date. Complete the inspection in accordance with paragraph 8 within the

next 10 flight hours but no later than 13 OCT 00 and report in accordance with paragraph 14b.

3. Reporting Compliance Suspense Date. Report compliance in accordance with paragraph 14a no later

than 20 OCT 00.

Summary of the Problem.

a. A category I deficiency report was received which reported corrosion on the inside surface of the

forward yoke shaft, part number 145C3051--1. The inside surface is required to be painted with primer. In-

spection revealed that the primer only covered the first 3 or 4 inches of the inside bore with the unpainted

portion exhibiting corrosion.

For manpower/downtime and funding impacts see paragraph 12.

The purpose of this Technical Bulletin is to --

(1) Require a one time inspection of all forward yoke shafts, part number 145C3051--1.

(2) Apply CPC to shafts found to have corrosion.

(3) Add forward yoke shaft inspection to phase maintenance manual.

(4) Replace forward yoke shafts that exhibit signs of corrosion no later than 31 DEC 01.

End Items to be inspected . All H--47 series aircraft.

Assembly Components to be Inspected. N/A.

Parts to be Inspected .

NOMENCLATURE

PART NUMBER

NATIONAL STOCK NUMBER

Forward Yoke shaft

145C3051--1

3040--01--116--4323

Inspection Procedures.

a. Use a borescope, if available, to determine if the entire inside surface of the shaft is painted or if there

is evidence of corrosion. The paint will be yellow/green in color. Use of a borescope should allow this inspec-

tion to be performed without removing the shaft from the aircraft. If a borescope is not available, use a small

flashlight to perform the inspection. To properly inspect the shaft, you must view all of the interior surfaces

including the bottom of the inside diameter. If unable to properly inspect the shaft while installed on the aircraft,

remove the shaft in accordance with TM 55--1520--240--23, Task 11--212 or TM 1--1520--252--23, Task 11--230

to perform inspection.

(1) If the entire inside surface of the shaft is painted and there is no evidence of corrosion, no

further inspections are required until phase inspection. If the shaft was removed from the aircraft to facilitate