Airworthiness Directives; Boeing Models 727, 737, and 747 Series Airplanes; McDonnell Douglas Model DC-8 and DC-9 Series Airplanes, Model MD-88 Airplanes, and Models MD-11 and MD-90-30 Series Airplanes; Lockheed Models L-1011-385 Series Airplanes; Fokker Models F28 Mark 1000, 2000, 3000, 4000, and 0100 Series Airplanes; and British Aerospace Model Avro 146-RJ Series Airplanes

This amendment supersedes two existing airworthiness directives (AD), applicable to certain transport category airplanes equipped with certain Honeywell Standard Windshear Detection Systems (WSS). Those AD's currently require a revision to the FAA-approved Airplane Flight Manual (AFM) to alert the flightcrew of the potential for significant delays in the WSS detecting windshear when the flaps of the airplane are in transition. Those AD's were prompted by a report of an accident during which an airplane encountered severe windshear during a missed approach. This amendment requires that the currently- installed line replaceable unit (LRU) be replaced with a modified LRU having new software that eliminates delays in the WSS detecting windshear when the flaps of the airplane are in transition. The actions specified by this AD are intended to prevent significant delays in the WSS detecting hazardous windshear, which could lead to the loss of flight path control.