Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain British Aerospace Model BAe 146 and Model Avro 146-RJ series airplanes. This proposal would require repetitive tests of the integrity of the electrical circuit between the windshear computer and the flap position sensor, and repair of the electrical wiring, if necessary. This proposal also would require replacement of certain windshear computers with new computers, which, when accomplished, terminates the repetitive tests. This proposal is prompted by a report indicating that the existing windshear computer is not capable of detecting a signal indicating loss of flap position; this could result in the flightcrew following erroneous computer-generated guidance. The actions specified by the proposed AD are intended to prevent the incapability of the windshear computer to detect the true flap position, which, if not corrected, could result in the inability of the flightcrew to avoid a windshear encounter, and consequent reduced controllability of the airplane.