AD 62-19-02

62-19-02 LOCKHEED: Amdt. 477 Part 507 Federal Register August 23, 1962. Applies to All Models 49, 149, 649, 749, and 749A Series Aircraft Incorporating Cleveland Pneumatic Tool Company Main Landing Gear Pistons, P/N's 8298-4, 8298B-4, 8298C-4, 8298C-4A, 8298D- 4 or 8298F-4.

Compliance required as indicated.

As a result of one complete fatigue failure and subsequent cases of cracks in numerous pistons in the area immediately above the weld that retains the metering pin bulkhead, accomplish the following:

(a) Within the next 800 hours' time in service after the effective date of this AD, and thereafter at intervals not to exceed 2,000 hours' time in service, inspect the main landing gear pistons, Cleveland Pneumatic Tool Company, P/N's 8298-4, 8298B-4, 8298C-4, 8298C-4A, 8298D-4, and 8298F-4, for cracks in the area immediately above the weld that retains the metering pin bulkhead. In those cases where an inspection in accordance with the procedures described in this AD hasbeen accomplished within the last 1,200 hours' time in service as of the effective date of this AD, that inspection may be considered as the initial inspection, and the repetitive reinspection intervals shall then start no later than 2,000 hours' time in service from that date. This inspection may be made by dye penetrant, magnetic particle or ultrasonic methods.

(1) Pistons with cracks which exceed a depth of 0.050 inch as measured from the piston inner wall surface shall be modified in accordance with paragraph 4(b) of Lockheed Field Service Letter No. FS/256603L, dated January 24, 1962, or an FAA approved equivalent in order to be eligible for further use. Pistons with this modification are redesignated Cleveland Pneumatic Tool Company P/N's 8298C-4B, 8298C-4C, 8298D-4A, 8298F-4A.

(2) Pistons with cracks which do not exceed a depth of 0.050 inch as measured from the piston inner wall surface shall be repaired in accordance with paragraph 4(a) of Lockheed Field Service Letter No. FS/256603L, dated January 24, 1962, or an FAA approved equivalent in order to be eligible for further use. Repaired pistons shall be identified by stamping a letter "R" in front of the part number.

(3) Pistons showing no evidence of cracks and pistons repaired in accordance with (a)(2) may be returned to service subject to the 2,000 hours' repetitive reinspection intervals.

(b) When modified pistons, P/N's 8298C-4B, 8298C-4C, 8298D-4A, or 8298F-4A, or FAA approved equivalent are installed, the periodic reinspections of (a) may be discontinued.

(c) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Western Region, may adjust the repetitive inspection intervals 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 such operator.

(Lockheed Field Service Letter No.FS/256603L dated January 24, 1962, covers this same subject.)

This directive effective September 24, 1962.