Airworthiness Directives: Terra Corporation TRT 250 Series Transponder

摘要

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to the Terra Corporation TRT 250 series transponder (transponder). This proposal would require removing the transponder from the aircraft, inspecting it to determine if the AD applies, and replacing any affected transponder with a modified Terra Corporation transponder or another transponder that responds properly to Mode S interrogations from both an ATCRBS/Mode S ground station and TCAS II airborne equipment. This proposal is prompted by FAA tests that show that the transponder does not reply to certain interrogations by a Mode S or Traffic Collision Avoidance System (TCAS) II signal. The actions specified by the proposed AD are intended to prevent failure of the transponder to reply to Mode S interrogations from both Mode S ground stations and TCAS II airborne equipment which could result in loss of airspace separation.