Regulacje i polityka gospodarcza · 28.12.1999

Airworthiness Directives; Boeing Model 747 Series Airplanes

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This proposal would require a one-time inspection to determine whether H-11 steel bolts are installed as attach and support bolts at the trailing edge flap transmissions, and replacement of any H-11 steel bolt with an Inconel bolt. This proposal is prompted by reports of fracture or cracking of H-11 steel bolts at the flap transmissions. The actions specified by the proposed AD are intended to prevent loss of a flap transmission, which could reduce lateral controllability of the airplane.