Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all The Boeing Company Model 777 airplanes. This proposed AD was prompted by a report of a crack found in a front spar lower chord undergoing an underwing longeron replacement. This proposed AD would require repetitive inspections for cracking of the left and right side ring chords, repair angles, front spar lower chords, and front spar webs (depending on configuration) common to the underwing longeron located at station (STA) 1035; modification of the front spar lower chord for some airplanes; repetitive post-modification inspections; and applicable on-condition actions. The FAA is proposing this AD to address the unsafe condition on these products.