Change 7.1 is a safety enhancement for TCAS II products that have been mandated by the European Aviation Safety Agency (EASA) and has strong support from the FAA.
The primary changes to the TCAS operation with Change 7.1 are:
- Reversal Logic Enhancements
- “Level Off” Aural Alert
- Change to Descend RAs at Low Altitude
Change 7.1 also addresses these performance issues identified with TCAS Change 7.0:
- SA01: Failure of TCAS to Reverse some RAs when a Reversal is Required to Resolve the Collision.
- SA-AVSA: Frequent Instances of Flight Crews’ Unintentional Incorrect Maneuvers to “Adjust Vertical Speed” RAs.
European Aviation Safety Agency (EASA) Mandate:
EASA issued a mandate for implementing TCAS Change 7.1 for aircraft operating in European airspace. EASA’s mandate calls for Change 7.1 software to be installed on all existing aircraft using TCAS II products by December 2015. Once Change 7.1 is installed, operators will be compliant with the new C119c TCAS standard.
FAA Strong Supporter:
- FAA Published the TCAS II version 7.1 Technical Standard Order (TSO)
- FAA AC 120-55C – Air Carrier Operational Approval and Use of TCAS II
- “The latest version of software for TCAS II is version 7.1. To ensure compatibility with international standards, the FAA encourages the installation of this software as soon as practical.”