Airworthiness Directive · Amendment 39-11418 · Various Transport Category Airplanes Equipped With Mode ``C'' Transponder(s) With Single Gillham Code Altitude Input
Various Transport Category Airplanes Equipped With Mode ``C'' Transponder(s) With Single Gillham Code Altitude Input
Superseded. A later AD replaced this one: AD 99-23-22 R1. Comply with the one in force.
Transport category airplanes, certificated in any category, equipped with any Mode "C" transponder with single Gillham code altitude input, including, but not limited to, the transponder part numbers listed below. A Mode "C" transponder with single Gillham code altitude input is defined as any Mode "C" transponder meeting Aeronautical Radio, Inc. (ARINC) 572 specification. Mode "C" Transponder Part Numbers: Rockwell Collins: 622-2224-001, 622-2224-003, 522-2703-001, 522- 2703-011, 787-6211-001, 787-6211-002 Bendix: 066-1056-00, 066-1056-01, 066-1123-00, 2041599-6508 Wilcox: 97637-201, 97637-301 IFF: APX-100, APX-101
This amendment adopts a new airworthiness directive (AD) that is applicable to various transport category airplanes equipped With certain Mode ``C'' transponder(s) with single Gillham code altitude input. This action requires repetitive tests to detect discrepancies of the Mode ``C'' transponder(s), air data computer, and certain wiring connections; and corrective actions, if necessary. This amendment is prompted by reports that, during level flight, the Traffic Alert Collision Avoidance System (TCAS II) issued false advisories that directed the flightcrew to change course and either climb or descend. The actions specified in this AD are intended to prevent such false advisories due to inaccurate airplane altitude reporting, which could result in the flightcrew deviating the airplane from its assigned flight path and a possible mid-air collision.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Appliances and equipment
