What is ETOPS and why is it required for twin-engine airliners?

ETOPS (Extended-range Twin-engine Operational Performance Standards) is an ICAO and FAA regulation governing flight routes where a twin-engine aircraft operates more than 60 minutes flying time from an adequate emergency diversion airport with one engine inoperative.

What are standard ETOPS ratings (120, 180, 240, 370 minutes)?

ETOPS ratings determine the maximum allowable single-engine flight time to a diversion airfield in still air. ETOPS 120 permits standard oceanic crossings; ETOPS 180 opens 95 percent of global oceanic airspace; and ETOPS 240 to 370 enables direct routes across polar and remote southern oceans.

What is an Equal Time Point (ETP) in oceanic navigation?

An Equal Time Point (ETP), or Critical Point, is the point along a route where flight time to proceed to the forward alternate airport is exactly equal to the flight time to return to the rearward alternate under single-engine cruise conditions.

ETOPS Diversion Buffer & Alternate Airport Mapper

Oceanic ETOPS Architecture

Simulates single-engine diversion radii for twin-engine airliners across 60, 120, 180, 240, and 370 minute certification tiers.
Features geographic positions and operational capabilities for 18 primary oceanic en-route diversion alternates.
Plots standard transatlantic and transpacific tracks against ETOPS diversion buffers to identify Equal Time Points (ETP).

Flight & Airframe Parameters

Aircraft Model & Max Certification

Operational ETOPS Limit Selected

Standard Oceanic Flight Corridor

Single-Engine Speed 430 kts

Diversion Radius 1,290 NM

Oceanic Buffer Area 5.2M sq NM

Compliance Status 100% Covered

Equal Time Point (ETP): In the event of engine failure or loss of pressurization at cruise, the flight crew diverts to the nearest alternate within the designated radius based on still-air single-engine true airspeed.

Oceanic Diversion Buffer Visualization

Keyless Esri Dark Tiles Real-Time Geodesic Radii

Designated Alternate

Single-Engine Safe Buffer

Flight Track

Primary Oceanic En-Route Alternates

ICAO / IATA	Airport Name	Jurisdiction	Coordinates	Longest Runway	Airspace Region
BIKF / KEF	Keflavik International	Iceland	63.98N, 22.61W	10,020 ft	Transatlantic North
CYQX / YQX	Gander International	Canada	48.94N, 54.57W	10,200 ft	Transatlantic West
EINN / SNN	Shannon Airport	Ireland	52.70N, 8.92W	10,500 ft	Transatlantic East
LPAZ / SMA	Santa Maria Airport	Azores (Portugal)	36.97N, 25.17W	10,003 ft	Mid-Atlantic
TXKF / BDA	L.F. Wade International	Bermuda	32.36N, 64.68W	9,698 ft	West Atlantic
FHAW / ASI	Wideawake Airfield	Ascension Island	7.97S, 14.39W	10,000 ft	South Atlantic
PACD / CDB	Cold Bay Airport	Alaska (USA)	55.21N, 162.72W	10,415 ft	North Pacific
PANC / ANC	Ted Stevens Anchorage	Alaska (USA)	61.17N, 150.00W	12,400 ft	North Pacific
PHNL / HNL	Daniel K. Inouye International	Hawaii (USA)	21.32N, 157.92W	12,300 ft	Mid Pacific
PMDY / MDY	Henderson Field	Midway Atoll	28.20N, 177.38W	7,800 ft	Central Pacific
NTAA / PPT	Faa International	French Polynesia	17.55S, 149.61W	11,220 ft	South Pacific
SCIP / IPC	Mataveri International	Easter Island	27.16S, 109.42W	10,885 ft	South Pacific
YPXM / XCH	Christmas Island Airport	Australia	10.45S, 105.69E	6,900 ft	Indian Ocean
FMEP / RUN	Roland Garros Airport	Reunion	20.89S, 55.51E	10,500 ft	Indian Ocean
FACT / CPT	Cape Town International	South Africa	33.96S, 18.60E	10,502 ft	South African
NZAA / AKL	Auckland International	New Zealand	37.01S, 174.79E	12,000 ft	Australasia
BGSF / SFJ	Kangerlussuaq Airport	Greenland	67.02N, 50.72W	9,219 ft	Polar North
GOOY / DSS	Blaise Diagne International	Senegal	14.67N, 17.07W	11,483 ft	West African