AD 79-25-09

79-25-09 HAMILTON STANDARD: Amendment 39-3637. Applies to all Hamilton Standard 24PF propellers, P/N 764995-1, 764996-2, 764996-3, 767600-2, and 767600-3, incorporating P/N 738410-1 bell cranks and P/N 738405-1 pivots.

Compliance required as indicated.

To preclude fracture of the P/N 738410-1 bell crank and P/N 738405-1 pivot due to cyclic loading, replace the bell cranks and the pivots in accordance with the following schedule:

1. Bell cranks and pivots with less than 2,600 hours time in service as of the effective date of this AD shall be removed from service prior to the accumulation of 3,000 hours time in service.

2. Bell cranks and pivots with 2,600 hours or more time in service as of the effective date of this AD shall be removed from service prior to the accumulation of 400 additional hours time in service.

This AD establishes a 3,000 hour life limit for bell crank P/N 738410-1 and pivot P/N 738405-1.

NOTE: Hamilton Standard Service Bulletin HSCode 24PF, No. 13, "Propellers - Extension Dome Assembly - Replacement of Bell Crank and Bell Crank Pivots," dated August 15, 1979, pertains to this subject.

Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, New England Region, may adjust the replacement interval specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator.

This amendment becomes effective December 24, 1979.