75-03-05 HAMILTON STANDARD: Amendment 39-2025. Applies to propeller Models 54H60-63, -81, -91, -111, -117, and -125.
Compliance required as indicated, unless already accomplished.
To prevent inflight separation of the extension sleeve, P/N 541850, Change B or earlier revision, from the pitch lock regulator assembly resulting in propeller pitchlocking, accomplish the following:
A. Propellers with a total of 2500 or more hours in service as of the effective date of this AD or whose total time in service is unknown, accomplish the requirements of Paragraph (C) below within the next 100 hours time in service.
B. Propellers with less than 2500 hours total time in service as of the effective date of this AD, accomplish the requirements of Paragraph (C) below prior to the accumulation of 2600 hours total time in service.
C. 1. Replace the fluid transfer housing extension sleeve, P/N 541850B or earlier revision, with an extension sleeve, P/N 541850C or later revision,or with a modified extension sleeve in accordance with Hamilton Standard Service Bulletin HS Code 54H60, No. 59, Revision No. 1, dated August 1, 1972, or later FAA approved revision, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region.
2. Replace the surge valve housing, P/N 543734B or earlier revision, with housing P/N 543734C or later revision, or replace surge valve housing, P/N 535299E or earlier revision with housing P/N 535299F or later revision.
The Manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Hamilton Standard, Division of United Aircraft Corporation, Windsor Locks, Connecticut 06096. These documents may also be examined at the Office of the Regional Counsel, New England Region, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803.
This amendment becomes effective on February 5, 1975.