s TTR-920 Change 6.04a Receiver Transmitter to a Collins TCAS II or TCAS 94 (TCAS II) system installation with Collins TTR-920 or Collins 17R-921 or Cellists TTR-4000 Change 7.0 TCAS 11 Receiver Transmitter and optional TPR-901 in accordance with Collins Installation Instructions as listed on AML No. ST0088IWID, Revision -,