Airworthiness Directives; Piaggio Aviation S.p.A. Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Piaggio Aviation S.p.A. (Piaggio) Model P-180 airplanes. This AD is 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 AD requires 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 is terminating action for the repetitive inspections. The FAA is issuing this AD to address the unsafe condition on these products.