Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain transport category airplanes equipped with certain Honeywell Standard Windshear Detection System (WSS). This proposal would require a revision to the FAA- approved airplane flight manual to alert the flightcrew of the potential for significant delays in the WSS detecting windshear when the flaps of the airplane are in transition. The proposal also would require replacement of the currently-installed line replaceable unit (LRU) with a modified LRU having new software that eliminates delays in the WSS. This proposal is prompted by a report of an accident during which an airplane encountered severe windshear during a missed approach. The actions specified by the proposed AD are intended to prevent significant delays in the WSS detecting hazardous windshear, which could lead to the loss of flight path control.