1AD/HU 369/95 - Main Rotor Transmission - Clutch Bearing - Outer Race Change

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters

AD/HU 369/95 Main Rotor Transmission - Clutch

Bearing - Outer Race Change

8/98

DM

Applicability: Model 369, 369A, 369D,369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N,

YOH-6A and OH-6A helicopters.

Requirement: Inspect the overrunning clutch assembly outer race, part number (P/N) 369A5352, to determine its serial number (S/N) in accordance with paragraphs A thru’ C of the Accomplishment Instructions contained in McDonnell Douglas Helicopter Systems Service Information Notice HN-215.2, DN-156.2, EN-46.2, FN-34.2, NN-010, dated March 18 1997 (service information notice). Remove any overrunning clutch outer race, P/N 369A5352 having a serial number S/N of 0692 through 0927, and replace it with an airworthy overrunning clutch outer race P/N 369A5352-5, together with a wave washer, P/N W1593-018, in accordance with the service information notice.

Note: FAA AD 98-09-02 Amdt 39-10481 refers.

Compliance: Within 50 hours time in service from the effective date of this directive.

This airworthiness directive becomes effective on 20 May 1998.

Background: This AD supersedes AD/HU 369/75. The requirement of the directive is extended to replace all outer races with a certain serial number regardless of heat treatment code. The previous AD merely inspected the races and replaced a limited number subject to the heat treatment code. Experience in the USA has shown that failures have occurred regardless of heat treatment code and the FAA has now mandated that all outer races of a certain batch require replacement.