80-26-05: Main Landing Gear Door Hinges

80-26-05 PIPER: Amendment 39-3994. Applies to Piper Models PA-31, PA-31-300, PA-31-325, Serial Nos. 31-2 thru 31-8012077; PA-31-350, Serial Nos. 31-5001 thru 31- 8052168; PA-31P, Serial Nos. 31P3 thru 31P-7730012; PA-31T1, Serial Nos. 31T-7804001 thru 31T-8004040; and PA-31T, Serial Nos. 31T-7400002 thru 31T-8020076 certificated in all categories. To prevent hazards associated with failed landing gear door attachments interfering with landing gear operation, accomplish the following: a. Within the next 100 hours in service from the effective date of this AD and thereafter at intervals not to exceed 100 hours in service from the last inspection, inspect the main landing gear inboard door hinges and hinge attachment angles in accordance with the "Instructions" section of Piper Service Bulletin No. 682 dated July 24, 1980, or equivalent. b. If cracks are observed, repair in accordance with the "Instructions" section of Piper Service Bulletin No. 682 dated July 24, 1980, or equivalent, prior to further flight, except the aircraft may be flown in accordance with FAR 21.197 to a base where a repair can be made. c. Upon the incorporation of, or the determination that the door hinges are P/N 47529-32, or are an equivalent part, the repetitive inspection of the hinges may be discontinued. Hinges manufactured by Piper from .250 sheet steel have been found to be equivalent to P/N 47529-32. d. Upon the incorporation of, or the determination that the hinge attachment angles are P/N 42048-02, -03 or are an equivalent part, the repetitive inspection of the angles may be discontinued. Four inch long angles manufactured by Piper have been found to be equivalent to P/N 42048-02, -03. e. Equivalent inspections, repairs and parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region. f. Upon the submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region may adjust the inspection interval specified in the AD. This amendment is effective December 19, 1980.