AD 77-10-11

77-10-11 GENERAL DYNAMICS: Amendment 39-2905. Applies to Models 240, 340/440 airplanes, including those modified for turbopropeller power per STC's SA1054WE, SA1096WE and SA4-1100, certificated in all categories.

Compliance required as indicated.

To detect stress corrosion to the aluminum uplock quadrant lug in the nose landing gear and prevent possible failure of the lug, accomplish the following:

a. Within the next 60 hours time in service after the effective date of this AD, and at intervals not to exceed 60 hours time in service thereafter, until (c), below, is performed:

(1) Remove the AN 3-21 bolt attaching the nose landing gear uplatch release cable clevis and the emergency release cylinder to the uplock assembly.

(2) Inspect P/N 240-5250109-6 nose landing gear uplock quadrant for cracks in the AN3 bolt attach lug using a 2X or stronger magnifier, or dye penetrant method.

(3) If cracks are found, prior to further flight, replace the quadrant with either a new aluminum quadrant, P/N 240-5250109-6, or a steel quadrant, P/N 240-5250109-9. If a new aluminum quadrant is installed, perform steps (1) through (4) at intervals not to exceed 600 hours time in service.

(4) Reinstall the AN3 bolt attaching release cable and emergency release cylinder and check rigging of the nose landing gear uplock installation per the applicable maintenance manual.

b. After the effective date of this AD, all aluminum quadrants, P/N 240-5250109-6, must be replaced before accumulating 1,200 hours time in service.

c. Installation of a steel quadrant, P/N 240-5250109-9, constitutes terminating action for this AD, and normal maintenance practices may be observed.

d. Special flight permits may be issued in accordance with FAR 21.197 to authorize operation of the aircraft to a base for the accomplishment of the inspections required by this AD.

e. Equivalent inspections and replacement parts may be used when approved by the Chief,Aircraft Engineering Division, FAA Western Region.

Note: General Dynamics Service Bulletins 600 (240D) Service Bulletin No. 32-3 and 640 (340D) Service Bulletin No. 32-2 pertain to this same subject.

This amendment becomes effective May 26, 1977.