The FAA has issued an emergency airworthiness directive (AD) designed to detect and correct fatigue cracks in the wing attach angles of Rockwell International and Autair Ltd. Models AT-6 (SNJ-2), AT-6A (SNJ-3), AT-6B, AT-6C (SNJ-4), AT-6D (SNJ-5), AT-6F (SNJ-6), BC-1A, Harvard (Army AT-16), SNJ-7, and T-6G airplanes. The AD affects all serial numbers certificated in any category.
The emergency action was prompted by the fatal May 9 crash of a Rockwell International SNJ-6 (AT-6F) used for aerobatic training. The accident investigation revealed a large fatigue crack in the lower inboard wing attach angle that caused the wing to fail.
The AD becomes effective upon receipt and requires immediate and 200-hour repetitive fluorescent penetrant inspections of the inboard and outboard, upper and lower wing attach angles (except for the nose angles) of both wings for fatigue cracks; and, if any crack is found, replacement of the cracked angle with a new angle.
The AD allows for a repositioning flight within 10 hours time in service, provided the flight takes place no later than July 8. Until the initial inspection is performed, acrobatic maneuvers, flight into known or forecast moderate or severe turbulence, and passenger carrying are prohibited. Flights may be conducted in day VFR conditions only.
June 9, 2005