Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737-300, -400, and -500 series airplanes. This proposed AD was prompted by a report that a crack indication consistent with fatigue cracking was found on the left nacelle support overwing fitting flange fastener hole during teardown of a Model 737-300 series airplane. This proposed AD would require a general visual inspection of the strut to wing diagonal brace at a certain location for cracking. For certain airplanes, this proposed AD would also require an ultrasonic inspection of certain fasteners of the nacelle support overwing fitting at a certain location for cracking. For certain other airplanes, this proposed AD would also require a magnetic check of the nacelle support overwing fitting at a certain location to determine the material composition. This proposed AD would also require applicable on-condition actions. The FAA is proposing this AD to address the unsafe condition onthese products.