ETOPS
ETOPS, Extended-range Twin-engine Operational Performance Standards, governs how far a twin-engine aircraft may fly from the nearest suitable airport, expressed in minutes of single-engine flying time. It was written for airlines, and many business jet operations are exempt or use similar oceanic rules, but it becomes relevant for bizliners and for Part 135 operators flying twin-engine jets over long stretches of ocean, where the aircraft, maintenance programme and crew must be specifically approved. For a customer this occasionally explains why a particular aircraft cannot take a direct routing across the South Pacific or must add a technical stop on a remote route while another type of the same size can fly straight.