Jet Aviation Basel developed European Aviation Safety Agency (EASA) Supplemental Type Certification (STC) for the Traffic Alert and Collision Avoidance System (TCAS II) version 7.1 upgrade. Jet Aviation Basel now has an STC approved by EASA for the TCAS II version 7.1 upgrade. TCAS II provides vertical rate “Resolution Advisories” (RAs) to pilots, informing them when and how to adjust their vertical speed in order to avoid collisions. All aircraft manufactured since March 2012 are equipped with TCAS II version 7.1. Any aircraft equipped with TCAS II version 7.0 software and operating within European Union airspace must upgrade to version 7.1 by December 1, 2015. The TCAS II version 7.1 upgrade improves flight safety by correcting an issue with the TCAS reversal logic in the event that one of the alerted crews does not comply with a resolution advisory or initiates an opposite maneuver. The upgrade also replaces several confusing “Adjust Vertical Speed” RAs with a single “Level Off” RA.