ETOPS

thumb|upright=2|The difference between an ETOPS-enabled shorter flight path (the solid green line) and a flight path for non-ETOPS aeroplane (the dashed blue line), the latter being curved due to the required distance to alternates

The Extended-range Twin-engine Operations Performance Standards (ETOPS) () are safety standards set by the International Civil Aviation Organization (ICAO) for twin-engine commercial passenger aircraft operations. They are a safety measure intended to ensure that in the event of a single engine failure, an aircraft will still be able to reach a diversion airport using the remaining operational engine, albeit at a reduced speed or altitude. The standard typically applies to long-distance routes over water or remote areas, which were historically restricted to three- and four-engine aircraft.