Transport i lotnictwo · 15/02/1995

Airworthiness Directives; Boeing Model 747-400 Series Airplanes

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 747- 400 series airplanes, that currently requires a revision to the input wiring for the flap control unit. This action would require a new systems test for the wiring of the trailing edge flap. The proposal would also expand the applicability of the existing AD to include additional airplanes. This proposal is prompted by a report indicating that a wiring error was not detected by the system test required by the existing AD. The actions specified by the proposed AD are intended to prevent the possibility of an all-flaps-up landing due to the loss of control of all flap operations.