Question: is tcas required for part 135?
Answer: Regulatory Requirements For operations conducted under FAR part 135, the aircraft must be equipped with TCAS if it is turbine powered and has 10 to 30 passenger seats (FAR 135.180). Whether the aircraft is operated under part 91 or part 135, if it is equipped with TCAS II, it must be version 7 (TSO C-119).