Carriage and Operation of Airborne Collision Avoidance System (ACAS) II 1.8.1 ACAS II shall be carried and operated in the NAT Region by all aircraft which meet the following criteria a) with effect from 31 March 2001, all turbine engine aeroplanes having a maximum certificated takeoff mass exceeding kg (lbs) or authorized to carry more than 30 passengers and
North Atlantic Guidance Material 1-5 7 th Edition b) with effect from 1 January 2005, all turbine engine aeroplanes having a maximum certificated takeoff mass exceeding 5700 kg (lbs) or authorized to carry more than 19 passengers.