ETOPS

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 last one is curved due to the required distance to alternates

TheExtended-range Twin-engine Operations Performance Standards (ETOPS)(/iːˈtɒps/) are safety standards set by theInternational Civil Aviation Organization(ICAO) fortwin-enginecommercial 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 adiversion airportusing the remaining operational engine. This may be at a reduced speed and/or height, and usually applies to flights over water or remote lands, typically routes previously restricted to three- and four-engine aircraft.

History

In 1936, the predecessor to theFederal Aviation Administration(FAA), the U.S.Bureau of Air Commerce,restricted commercial operations within United States airspace to within 100 mi (160 km) of an adequate airport. For many aircraft of that era this meant about 60 minutes with one engine inoperative.

In 1953, withpiston enginereliability and aircraft performance improved, U.S. authorities introduced a "60-minute rule", restricting twin-engine aircraft to a 60-minute diversion area (at single-engine cruise speed). There was some additional flexibility beyond this limit with special approval. Meanwhile theInternational Civil Aviation Organization(ICAO) recommended a 90-minute diversion time for all aircraft, which was adopted by many regulatory authorities and airlines outside the US.

During the 1950s,Pan Amtwin-engineConvair 240sflew across the Caribbean fromBarranquilla, ColombiatoKingston, Jamaica,AvensaConvair 340sflew fromMaracaibo, VenezuelatoMontego Bay, Jamaica,KLMDouglas DC-3sflewCuracaotoCiudad Trujillowhile KLM Convairs flewArubato Kingston withDelta Air LinesoperatingConvair 340flights nonstop betweenNew OrleansandHavanaas well as nonstop between Havana and Montego Bay and also on a routing of Havana –Port au Prince– Ciudad Trujillo –San Juan, Puerto Rico.In 1948–52New Zealand National Airways Corporationscheduled a DC-3 to fly from Apia (Western Samoa) to Aitutaki, a5+1⁄2-hour flight covering 685 airportless nautical miles between Tafuna (Pago Pago) and Aitutaki. In 1963Polynesian Airlinesstarted flying aPercival PrinceApia to Aitutaki; in 1964 the flight was a DC-3 from Faleolo (Upolu) to Aitutaki, a distance of 768 nautical miles (1,422 km; 884 mi). More recently, the January 1979 OAG showed a weekly Polynesian AirlinesHS748from Niue to Rarotonga, 585 nmi (1,083 km; 673 mi) with no airport.

In 2017 ICAO issuedStandards and Recommended Practices(SARPS) for ETOPS, and ETOPS were extended to four-engine aircraft like theBoeing 747-8and the terminology updated to EDTO (Extended Diversion Time Operations).

Early jet airliners

While the earliest jet engines were sometimes unreliable, widespread use of later engines such as thePratt & Whitney JT8D(e.g.McDonnell Douglas DC-9andBoeing 737) led to major advances in reliability and safety. As jet engines started to deliver more power than piston engines while increasing reliability, aircraft whose size previously required four piston engines could now be built using only two jet engines.

By the late 1960s, most large civil airliners were jet-powered, relegating the piston engine to roles such as cargo flights. With the JT8D reliably powering the three-engineBoeing 727,the 60-minute rule was waived in 1964 for three-engine aircraft, which in turn opened the way for the development ofwide-body,intercontinentaltrijetssuch as theLockheed L-1011 TriStarandMcDonnell Douglas DC-10.By then, only twin-engine jets were restricted by the 60-minute rule. Trijets and quadjets dominated international long-haul flights until the late 1980s.

Early ETOPS

TheAirbus A300B4became the first ETOPS-compliant aircraft, in 1977

Airbus A300twinjets, the first twin-engine wide-body aircraft, had been flying across the North Atlantic, the Bay of Bengal, and the Indian Ocean under a 90-minute ICAO rule since 1976.

When theFAAdirectorJ. Lynn Helmsin 1980 was approached about the possibility of an exemption, his response was "It'll be a cold day in hell before I let twins fly long haul, overwater routes."TheBoeing 767-200ERentered service in 1984.

In 1985, the FAA increased the ETOPS to 120 minutes at the single-engine cruise speed.Trans World Airlinesoperated the first 120-minute ETOPS (ETOPS-120) service on February 1, 1985, with aBoeing 767-200 from Boston to Paris. The 767 burned 7,000 lb (3.2 t) less fuel per hour than aLockheed L-1011 TriStaron the same route, prompting TWA to spend $2.6 million on each 767 they owned to retrofit them to ETOPS-120 specs. It was followed bySingapore Airlinesin June with anAirbus A310. In April 1986,Pan Aminaugurated transatlantic revenue service using A310s, and within five years Airbus ETOPS operators numbered more than 20.

ETOPS 180

Twin-engineBoeing 767-300ERover Alaska beginning an ETOPS 180 trans-Pacific crossing

In 1988, the FAA amended the ETOPS regulation to allow the extension to a 180-minute diversion period, subject to stringent technical and operational qualifications. ETOPS-180 and ETOPS-207 cover about 95% of the Earth.The first such flight was conducted in 1989. This set of regulations was subsequently adopted by the JAA, ICAO, and other regulatory bodies.

ETOPS 180 at introduction

TheBoeing 777was the first ETOPS 180 airliner at its introduction

The original 1985 regulations allowed an airliner to have ETOPS-120 rating on entry into service. ETOPS-180 was only possible after one year of trouble-free 120-minute ETOPS experience. In 1990 Boeing convinced the FAA that it could deliver an airliner with ETOPS-180 on its entry into service. This process was called Early ETOPS. The Boeing 777 was the first aircraft to be introduced with an ETOPS rating of 180 minutes.

In the 1990s, theJoint Aviation Authorities(JAA) demurred; on its entry into service in Europe, theBoeing 777was rated ETOPS-120. European airlines operating the 777 had to demonstrate one year of trouble-free 120-minute ETOPS experience before obtaining 180-minute ETOPS for the 777.

Beyond ETOPS-180

Effective February 15, 2007, the FAA ruled that US-registered twin-engine airplane operators can fly more than 180-minute ETOPS to the design limit of the aircraft. In November 2009, theAirbus A330became the first aircraft to receive ETOPS-240 approval, which has since been offered by Airbus as an option.

ETOPS-240 and beyond are now permittedon a case-by-case basis, with regulatory bodies in the United States, Australia, and New Zealand adopting said regulatory extension. Authority is only granted to operators of two-engine airplanes between specific city pairs. The certificate holder must have been operating at 180-minute or greater ETOPS authority for at least 24 consecutive months, of which at least 12 consecutive months must be at 240-minute ETOPS authority with the airplane-engine combination in the application.

In 2009 theAirbus A330was first to receive ETOPS-240 approval

On December 12, 2011, Boeing received type-design approval from the FAA for up to 330-minute extended operations for itsBoeing 777series, all equipped withGEengines, and withRolls-RoyceandPratt & Whitneyengines expected to follow.The first ETOPS-330 flight took place on December 1, 2015, withAir New ZealandconnectingAucklandtoBuenos Aireson a 777-200ER.On May 28, 2014, theBoeing 787received its ETOPS-330 certificate from the FAA, enablingLAN Airlines(now known as LATAM Airlines) to switch to the 787 from the A340 on their Santiago–Auckland–Sydney service a year later. Until the rule change in North America and Oceania, several commercial airline routes were still economically off-limits to twinjets because of ETOPS regulations, unless the route was specifically conducted as indivertible. There were routes traversing the Southern hemisphere, e.g., South Pacific (e.g.,Sydney–Santiago,one of the longest over-the-sea distances flown by a commercial airline), South Atlantic (e.g.,Johannesburg–São Paulo), Southern Indian Ocean (e.g.,Perth–Johannesburg), andAntarctica.

Before the introduction of the AirbusA350XWBin 2014, regulations in North America and Europe permitted up to 180-minute ETOPS at entry. The A350 XWB was first to receive an ETOPS-370 prior to entry into service by European authorities,enabling economical nonstop routes betweenEuropeandOceania(and thereby bypassing historical stopovers acrossAsiaandNorth America) by the late 2010s and early 2020s. This includes the high-demandLondon–Sydney route,in the latest development forultra long-haulflights. The A350 XWB's current ETOPS certification covers 99.7% of the Earth's entire surface, allowingpoint-to-point travelanywhere in the world except directly over theSouth Pole.

Meanwhile, the first time that ETOPS-330 approval was given to a four-engine aircraft was in February 2015, to theBoeing 747-8 Intercontinental.It is the only ETOPS-compliant aircraft allowed torun non-stop overflights over Antarctica with proper alternates,alongside theAirbus A340and A380.

Usage

TheNorth Atlantic Tracksare the most heavily used oceanic routes in the world, and are largely covered by ETOPS 120-minute rules, thereby removing the necessity of using 180-minute rules. However, North Atlantic diversion airports are subject to adverse weather conditions that affect their availability for use. As a result, the JAA and FAA have given 15% extension to the 120-minute rules to deal with such contingencies, resulting to ETOPS-138 (i.e. 138 minutes) to allow ETOPS flights with such airports closed. By the mid-2010s, virtually all North Atlantic plane routes were dominated by twin-engine aircraft.

During theCold War,routes between Europe and East Asia were prohibited from flying overSoviet UnionorChinasince both airspaces were previously heavily military-controlled. Virtually all flights between Europe and North East Asia flew over the United States, often with a tank stop inAnchorage,Alaska.They flew near theNorth Polewith a very large distance to usable airports, for which only three- and four-engine wide-body aircraft were permitted for safety reasons by international aviation authorities. Some flights between Europe and Oceania still largely pass through stopovers in Asia (either in theMiddle EastorSoutheast Asia) or North America (either inCanadaor the U.S.) given the current aircraft range restrictions and, in the case of the early 2020s, the reinstatement of selected routes by airlines between theWestern HemisphereandEastern HemispherebypassingRussia due to its ongoing war with Ukraine.

For decades,narrow-body aircraftlike theAirbus A320series, and theBoeing 737series and757have continuously operated flights as approved for ETOPS operation, alongside earlierwide-body aircraftsuch as the A300 andA310,andBoeing 767.The success of ETOPS aircraft likeA300and Boeing 767 made the intercontinentaltrijetsobsolete for passenger use, production of which was largely ended by the late 2000s with Boeing cancelling theMcDonnell Douglas MD-11program in the same period.

The rules have also allowed American legacy carriers (United AirlinesandDelta Air Linesin particular) to use the Boeing 757 on "long and thin" transatlantic routes between their major hubs and secondary European citiesthat cannot generate the passenger demand to justify the use of a widebody airliner. The practice has been controversial, because although the 757 has adequate range to cross the Atlantic Ocean comfortably, strong headwinds caused by thejetstreamover the winter months can result in westbound flights being declared "minimum fuel", forcing a refuelling stop atGander, Newfoundland,in order to safely complete their journey.

Aloha Airlinesoperated 180-minute ETOPS–approved Boeing 737-700 aircraft on nonstop routes between the Hawaiian Islands and the western U.S. and also Vancouver, Canada. The use of the smaller 737-700 enabled Aloha to serve routes that could not support larger jet aircraft with an example being theHonolulu–Burbanknonstop route. Prior to the 737-700 operation, Aloha Airlines had operated 737-200 aircraft to various Pacific islands utilizing 120 minute ETOPS.

Other new-generation ETOPS aircraft include theAirbus A220series, theEmbraer E-Jetsseries and theATR 72.By the mid-2010s, the widespread successes of ETOPS-reliant narrow-body aircraft have diminished the global market share of double-deck wide-body jets. At the onset of theCOVID-19 pandemicin the early 2020s, Boeing and Airbus have since ended all production of the747andA380,respectively (and both being the two largest commercial aircraft in the world). At the same time, the increasing prominence of new-generation ultra-long-range wide-body twinjets like theBoeing 777and787,andAirbus A330andA350over the last decade has shifted the favor fromquadjetstotwinjetsfor international long-haul travel.

Approval process

The cornerstone of the ETOPS approach is the statistics showing that the turbine assembly of a modern jet engine is an inherently reliable component. Engine ancillaries, by contrast, have a lower reliability rating. Therefore, an ETOPS-certified engine may be built with duplicate sets of certain ancillaries in order to receive the required reliability rating.

ETOPS approval is a two-step process. First, the airframe and engine combination must satisfy the basic ETOPS requirements during itstype certification.This is called "ETOPS type approval". Such tests may include shutting down an engine and flying the remaining engine during the complete diversion time. Often such tests are performed in the middle of the ocean. It must be demonstrated that, during the diversion flight, the flight crew is not unduly burdened by extra workload due to the lost engine and that the probability of the remaining engine failing is extremely remote. For example, if an aircraft is rated for ETOPS-180, it means that it is able to fly with full load and just one engine for three hours.

Second, an operator who conducts ETOPS flights must satisfy their own country's aviation regulators about their ability to conduct ETOPS flights. This is called "ETOPS operational certification" and involves compliance with additional special engineering and flight crew procedures in addition to the normal engineering and flight procedures. Pilots and engineering staff must be qualified and trained for ETOPS. An airline with extensive experience operating long distance flights may be awarded ETOPS operational approval immediately, while others may need to demonstrate ability through a series of ETOPS proving flights.

Regulators closely watch the ETOPS performance of both type certificate holders and their affiliated airlines. Any technical incidents during an ETOPS flight must be recorded. From the data collected, the reliability of the particular airframe-engine combination is measured and statistics published. The figures must be within limits of type certifications. Of course, the figures required for ETOPS-180 will always be more stringent than ETOPS-120. Unsatisfactory figures would lead to a downgrade or, worse, suspension of ETOPS capabilities either for the type certificate holder or the airline.

Engines must have an in-flight shutdown (IFSD) rate better than 1 per 20,000 hours for ETOPS-120, 1 per 50,000 hours for ETOPS-180, and 1 per 100,000 hours for beyond ETOPS-180.

Private jets are exempted from ETOPS by the FAA, but are subject to the ETOPS 120-minute rule inEASA'sjurisdiction.

Government-owned aircraft (including military) do not have to adhere to ETOPS regulations.

Ratings

There are different levels of ETOPS certification, each allowing aircraft to fly on routes that are a certain amount of single-engine flying time away from the nearest suitable airport. For example, if an aircraft is certified for 180 minutes, it is permitted to fly any route not more than 180 minutes' single-engine flying time to the nearest suitable airport.

The following ratings are awarded under current regulations according to the capability of the airliner:

• ETOPS-75
• ETOPS-90
• ETOPS-120/138
• ETOPS-180/207
• ETOPS-240
• ETOPS-270
• ETOPS-330
• ETOPS-370

However, ratings for ETOPS type approval are fewer. They are:

• ETOPS-90
• ETOPS-120/138
• ETOPS-180/207, which covers 95% of the Earth's surface.
• ETOPS->180 to design limit

Designation

Until the mid-1980s, the term EROPS (extended range operations) was used before being superseded by ETOPS usage. In 1997, when Boeing proposed to extend ETOPS authority for twins to beyond 180 minutes, Airbus proposed to replace ETOPS by a newer system, referred to as Long Range Operational Performance Standards (LROPS), which would affect all civil airliners, not just those with a twin-engine configuration with more than 180 minutes ETOPS.

US FAA

TheFAAstated in theFederal Registerin 2007:

This final rule applies to air carrier (part 121), commuter, and on-demand (part 135) turbine powered multi-engine airplanes used in extended-range operations. However, all-cargo operations in airplanes with more than two engines of both part 121 and part 135 are exempted from the majority of this rule. Today's rule [January 16, 2007] establishes regulations governing the design, operation and maintenance of certain airplanes operated on flights that fly long distances from an adequate airport. This final rule codifies current FAA policy, industry best practices and recommendations, as well as international standards designed to ensure long-range flights will continue to operate safely. "

and

Several commenters… recommended use of the acronym "LROPS" —meaning 'Long Range Operations'—for three- and four-engine ETOPS, to avoid confusion, particularly for those operations beyond 180 minutes' diversion time. The FAA has decided to use the single term, 'extended operations,' or ETOPS, for all affected operations regardless of the number of engines on the airplane. "

Prior to 2007, the FAA used the term forExtended Range Operation with Two-Engine Airplanesbut the meaning was changed when regulations were broadened to include aircraft with more than two engines.

EDTO – Extended Diversion Time Operations

In 2017 ICAO amendment 36 to Part I of Annex 6 of theChicago Conventionreplaced the term ETOPS with the new term EDTO (Extended Diversion Time Operations). The main reason of this change in the terminology was to better reflect the scope and applicability of these new standards.

Backronym

A colloquial aviationbackronymis "Engines Turn Or Passengers Swim", referring to the inevitable emergencywater landingof a twin engine aircraft after a doubleengine failureover water outside gliding range of land.

See also

• Twinjet
• Longest flights

External links

• "New ETOPS regulations"(PDF).Aero magazine.Boeing.April 2003.
• "Revision Of Rule for ETOPS and LROPS"(PDF).FAST Magazine.Airbus.July 2003. pp. 16–23. Archived fromthe original(PDF)on 2017-01-03.Retrieved2019-07-31.
• "FAA frees twins from ETOPS limits".Flight International.Reed Publication Limited. January 16, 2007.
• "New ETOPS Regulations"(PDF).Federal Aviation Administration.January 26, 2007.
• "The New FAA ETOPS Rule"(PDF).Aero Magazine.Boeing.April 2007.
• "Overview of new ETOPS / LROPS / EDTO rules"(PDF).Airbus.October 2011. Archived fromthe original(PDF)on 2017-01-03.Retrieved2016-05-10.
• "SAM Workshop on Extended Diversion Time Operations (EDTO)".ICAO. September–October 2014.
• "Great Circle Mapper".ETOPS option shades no-go areas
• "ETOPS (Extended range operations for two engine aeroplanes".Flight Crew Guide.24 September 2013.