51-13-01 MARTIN: Applies to All Models 202 and 202A Series Aircraft as Noted.
Compliance required as indicated.
1. Applies to all Serial Numbers except 9125 through 9127 and 9129 through 9131.
A. Compliance required every other No. 3 inspection period, approximately 620 hours flight time, or 6 months, whichever occurs first.
(1) Inspect the wing top cover splice angles with 2- to 6-power glass (may be conducted with paint on). On Model 202 Series aircraft, except Serial Numbers 9149 and 9150, these angles are P/N U23435 through U23442 (wedge assemblies Nos. 2021A12633 and 2021A12624). On Model 202 aircraft, Serial Numbers 9149 and 9150, and on all Model 202A Series aircraft, these angles are P/N A12025, A12026, U29403, U29404, U29407, and U29408 (wedge assemblies Nos. 2021A12023 and 2021A12024).
(2) If cracks are found, the top cover wedge assembly must be replaced as outlined in item B.
(3) Continue the inspections outlined in item A. until the replacementaction outlined in item B. is accomplished.
B. Compliance required not later than January 1, 1953.
(1) Replace all wing top cover wedge angles with new angles as follows: On Model 202 Series aircraft, except Serial Numbers 9149 and 9150, the new angles are P/N 202A3000068-1 and -2 through 202A3000071-1 and -2 (wedge assemblies Nos. 2021C12336-9 and -10). On Model 202A aircraft, Serial Numbers 9149 and 9150, and on all Model 202A Series aircraft, the new angles are P/N 202A3000072-1 and -2 through 202A3000074-1 and -2 (wedge assemblies Nos. 2021C12090-9 and -10).
(2) At the time of wedge assembly replacement, the outer wings must be reinstalled with the engines removed, and the mating faces shimmed to a maximum permissible gap of 0.020 inch. The rear spar fitting must also be shimmed to a zero gap for approximately the upper half of its area.
(3) Each airplane must have a torque check on the attach angle bolts immediately after the first flight after any outer wing installation. If the torque is within 15 percent of the installation torque, it is satisfactory.
(4) After the new wedge angles are incorporated, the inspection outlined in item A. is no longer applicable to that airplane.
2. Applies to Serial Numbers 9125 through 9127 and 9129 through 9131.
A. Compliance required every 170 hours flight time. Conduct the inspection outlined in above item 1.A. on angles P/N U23435 through U23442 (wedge assemblies Nos. 2021A12623 and 2021A12624) until cracks are found and/or the replacement action outlined in item B. below is accomplished.
B. Compliance required not later than May 15, 1952. Replace all wing top cover angles with new angles P/N 202A3000068-1 and -2 through 202A3000071-1 and -2, wedge assemblies Nos. 2121C12336-9 and -10, and when accomplished, the inspections outlined in above item A. are no longer applicable to that airplane.
3. Applies to all Model 202 and 202A Series.
A. Compliance required every 12,000 flighthours. Replace all wing top cover attach angle bolts and spar web splice bolt.
(Martin 202/202A Service Bulletins Nos. 180, 184, and 187 cover this same subject.)