DEPARTMENT OF THE ARMY TECHNICAL BULLETIN
MANDATORY MAINTENANCE FOR
ENGINE DRIVE SHAFT, P/N 145D3504-2,
Headquarters, Department of the Army, Washington, D. C.
28 March 2003
DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.
THIS PUBLICATION IS EFFECTIVE UNTIL RESCINDED OR SUPERSEDED.
Priority Classification. Urgent
MACOM Commanders may authorize temporary exception from mes-
sage requirements in accordance with AR 95--1, Chapter 6. Exception
may only occur when combat operations or matter of life or death in civil
disasters or other emergencies are so urgent that they override the con-
sequences of continued aircraft operation.
a. Background -- Application of MWO 55-1520-240-50-43 replaced three piece engine drive shaft, P/N
145D3500-15, with a one piece engine drive shaft, P/N 145D3504-2. At that time an interim retirement life
of 2000 hours was established. The interim retirement life was to remain in effect until fatigue testing was
conducted and verified. Based on fatigue test results, the retirement life of P/N 145D3504-2 can safely be
increased to 6000 hours for all but 49 of these shafts. These 49 shafts were flown on certain aircraft during
a specific time frame which cannot allow their retirement lives to be increased. These 49 specific serial num-
bered shafts will remain at the 2000 hour retirement life.
b. Message Purpose -- Increase the retirement life of all but 49 specific serial numbered engine drive
shafts from 2000 hours to 6000 hours.
End Items Affected. All H--47 series aircraft.
NATIONAL STOCK NUMBER
Engine Drive Shaft
This TB supersedes USAAMCOM Message 251331Z MAR 03 CH-47--03--ASAM-01.