AD 2014-18-01
Unsafe Condition
The TDR-94 and TDR-94D Mode S transponder internal software does not correctly implement the air/ground override function when the airplane type code strapping is set to any value other than (1) or (0) and the airplane rotation speed is greater than 100 knots. This error inhibits the Mode S Only All-Call replies.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the setting of the airplane type code category strapping. Either modify the airplane type code category setting or install the software upgrade to convert the affected transponders to the new part number.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Rockwell Collins TDR-94 and TDR-94D Mode select (S) transponders installed on airplanes, specifically those with airplane type code strapping set to values other than (1) or (0).
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.