Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This proposed AD was prompted by a report of an escapement from the wing spar terminal fitting supplier indicating that the engineering requirements provided by Boeing for controlling machine mismatch were incorrect for part faying surfaces, which can result in a reduced fatigue capability at the interface of the side of body (SOB) rib. This proposed AD would require repetitive inspections for fatigue cracking and applicable on- condition actions for the SOB rib webs where fastener locations attach the terminal fittings. The FAA is proposing this AD to address the unsafe condition on these products.