Duncan Aviation has been awarded the first STC and performed the first installation of a TCAS-4000 aircraft collision avoidance system (ACAS) in a Westwind 1124A. This STC includes the latest MOPS 7 software required for European operations. It covers the Westwind 1124/1124A airframes. According to the FAA notice of proposed rule making for reduced vertical separation minimum operations in the western atlantic traffic route system region, MOPS 7 software will be required for all TCAS II-equipped aircraft by November 1, 2001.