Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. This proposed AD was prompted by a report that during a C- check, corrosion was found in the vertical fin tension bolt hole located in the aluminum crown frames at Section 48. This proposed AD would require inspecting certain vertical fin tension bolt holes; reviewing the bolt sealant application installation procedure in the existing maintenance or inspection program, as applicable; checking maintenance records to determine the replacement status of vertical fin tension bolts; and doing applicable on-condition actions. The FAA is proposing this AD to address the unsafe condition on these products.