EASA SIB CE-19-19
Rockwell Collins TDR-94 and TDR-94D ATC/Mode S Transponders - Update of the Transponder System
Summary
The Special Airworthiness Information Bulletin SAIB: CE-19-19 informs owners and operators about detection and tracking issues with aircraft equipped with Rockwell Collins TDR-94 and TDR-94D ATC/Mode S Transponders modified by Service Bulletin TDR-94()-34-30. This bulletin addresses problems experienced by certain ground stations outside the United States, including Multilateration (MLAT) and Air Traffic Control Radar Beacon System (ATCRBS) stations. The issue does not currently warrant an airworthiness directive under 14 CFR part 39.
What Changed
SAIB CE-19-19 highlights the availability of an update to the TDR-94() transponder system that resolves detection and tracking problems near ground stations lacking Dynamic Minimum Trigger Level (MTL). The update is detailed in Rockwell Collins Service Bulletin TDR-94()-34-33 Revision No. 1 or later, which owners and operators of MOD "30" marked units are recommended to follow.
Why It Matters
This bulletin is important because it addresses potential gaps in aircraft detection by certain international ground stations, which could affect situational awareness and air traffic control tracking accuracy. Operators and maintenance teams need to be aware of these issues to ensure reliable transponder performance and avoid duplicate or lost radar returns, particularly near airports outside the United States.
What To Do
Owners and operators of aircraft equipped with Rockwell Collins TDR-94 or TDR-94D transponders marked with MOD "30" should consult Rockwell Collins Service Bulletin TDR-94()-34-33 Revision No. 1 or later for instructions on updating their transponder systems. There are no mandatory compliance deadlines stated, but timely action is recommended to improve ground station detection and tracking.