AD 50-13-01

50-13-01 CONVAIR: Applies to All Model 240 Aircraft.

Compliance required as indicated.

Failures of the wing portion of the aileron hinge brackets and bracket supports have been experienced on Convair Model 240 aircraft. These failures have been the result of excessive lateral vibration of the ailerons experienced mainly during engine operation between 1,000 to 1,200 r.p.m., in aircraft incorporating Hamilton Standard propellers. In order to preclude the possibility of these failures progressing to such a state that the airworthiness of the airplane is impaired, it is considered necessary that the following be accomplished on Convair Model 240 Series aircraft:

A. To be accomplished on all individual CV-240 Series aircraft incorporating Hamilton Standard propellers at every No. 2 operation, until part B, is accomplished.

Inspect the aileron in area of hinge brackets, aileron hinge brackets and bracket supports with a 10-power glass, for signs of fatigue cracking. Special attention should be paid to the areas around the rivet holes utilized for attaching the brackets to the bracket supports and to that portion of the bracket supports in the areas at which the bracket supports extend from the wing trailing edge structure. Any failed parts should be adequately repaired or replaced prior to the next flight.

B. To be accomplished by January 1, 1951, on airplanes incorporating Hamilton Standard propellers.

Incorporate steel aileron hinge brackets and incorporate measures to increase the lateral rigidity of the wing portion of the aileron hinges.

(CVAC Service Bulletin 240-289 covers this same subject.)