70-12-05 GENERAL DYNAMICS: Amendment 39-1003. Applies to General Dynamics 340 and 440 airplanes including those modified to turbopropeller power.
Compliance required as indicated.
To detect cracks and prevent failure of the MLG trunnion fitting P/N 340-8510109, accomplish the following:
Within the next 50 hours' time in service after the effective date of this AD, unless already accomplished within the last 450 hours' time in service, visually inspect MLG trunnion fittings P/N 340-8510109 for crack indications in the outboard fitting face and inboard boss area, primarily in the upper area of the fitting above the boss radius, by dye penetrant inspection procedures, in accordance with General Dynamics 640(340D) Service Bulletin No. 57-4, dated May 25, 1970, or later FAA approved revision or an equivalent inspection procedure approved by the Chief, Aircraft Engineering Division, FAA Western Region.
(a) If no cracks are found, repeat the above inspection procedure atinspection intervals not to exceed 500 hours' time in service from the last inspection.
(b) If cracks are found as a result of the above inspections, accomplish one of the following before further flight:
(1) If trunnion fitting cracking exceeds two inches or if a crack is found in the trunnion boss face, the fitting must be replaced.
(2) If cracking is in excess of one inch in length but less than two inches in length, either replace the fitting or stop-drill using a 0.25 inch drill and reinspect daily for crack growth until the fitting can be replaced.
(3) If cracking is one inch in length or less, either replace the fitting or stop- drill using a 0.25 inch drill and reinspect for crack growth at intervals not to exceed 50 hours' time in service.
NOTE: Where insufficient clearance precludes the use of a 0.25 inch drill it is permissible to use a 0.1875 inch drill.
(c) Replace stop-drilled fittings within 500 hours' time in service from the initial stop-drilling.
(d) Any crack progressing beyond a stop-drilled hole may be stop-drilled again if the total crack length is less than two inches. This fitting must be replaced if a crack progresses to two inches or more in length.
This amendment becomes effective June 11, 1970.