UK CAA defines ETOPS as "Extended range Twin Operations" »CAP789«. Arhivirano iz prvotnega spletišča(PDF) dne 23. septembra 2015. Pridobljeno 3. septembra 2013., EASA defines it as "Extended Range Operation with Two-Engine Aeroplanes" and ICAO as "Extended-range Twin-engine Operational Performance Standards"
UK CAA defines ETOPS as "Extended range Twin Operations" »CAP789«. Arhivirano iz prvotnega spletišča(PDF) dne 23. septembra 2015. Pridobljeno 3. septembra 2013., EASA defines it as "Extended Range Operation with Two-Engine Aeroplanes" and ICAO as "Extended-range Twin-engine Operational Performance Standards"