Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Piaggio Aviation S.p.A. (Piaggio) Model P-180 airplanes. This proposed AD was prompted by a report of corrosion on the various aluminum alloy reinforcements in the horizontal stabilizer (HS) central box caused by a humid environment inside the box from water ingress and/or condensation. This proposed AD would require a one-time detailed inspection of the HS central box for corrosion; an assessment of the corrosion level; and depending on the determination, repetitive detailed inspections of the HS central box for corrosion and the internal composite structure for surface cracks, distortion, and damage; and repair or replacement of the HS assembly. Repair or replacement of the HS assembly would be terminating action for the repetitive inspections. The FAA is proposing this AD to address the unsafe condition on these products.