Boeing 767 - Long-haul flights - ETOPS

ETOPS – small airplanes on a big journey

Tim Takeoff
22.10.2019
4 pictures
5 minutes

In the age of commercial aircraft, it has almost become a matter of course to bridge longer distances in an increasingly shorter time. Throughout the years an increasing number of main air traffic arteries have developed.

Remote routes

However, some routes lead across largely cut-off terrain or over large oceans. The large wide-body aircraft used on these long-haul routes also require suitably equipped airports and runway systems in emergencies. The legislator stipulates without further approvals that for the time being, an adequate alternative landing site for an aircraft with only two engines must not be further than 60 flight minutes away. This rule is based on a specification of the US-American aviation authority FAA and was established worldwide.

The hour circles

The flight operations officer, also called the flight dispatcher, traces a circle marking 60 flight minutes around all airports along the route. Each of these circles must overlap; if they do not overlap, the flight ought not to take place for the time being. To enable flights over the Atlantic, for example, one would have to fly large detours over Iceland, Greenland and northern Canada. This is often not ideal, as the large jet streams in this area have a significant influence on the flight. More direct routes over 60 minutes airport range needed to be established.

The early success of the three and four-engined jet aircraft

On most routes the use of large jets such as the Boeing 747 or the Airbus A340 was not profitable for the airlines. Underutilization of capacity is not economical at this stage. This was the beginning of the success of the then three-engined airplanes, like the McDonnell Douglas MD11, or the Lockheed TriStar. Due to their self-sufficiency, even in the event of an engine failure, the aeronautical authorities waived the obligation for an hour-circle control system. All of a sudden, the travel times over the so-called “remote areas” were drastically reduced. Flights over the Atlantic, Pacific, large parts of Russia or the highlands of Tibet could be carried out via direct routes.

The two-engined aircraft wins

Due to increasingly modern engines and aircraft, the three-engined airplanes also turned out to be no longer economical in the long run. Newly developed twin-engine aircraft such as the Boeing 767/ 777 or the Airbus A330 were developed in close collaboration with the authorities and had to meet numerous criteria (redundancies of flight control systems, etc.) in order to be allowed to operate these direct routes with just two engines. Aircraft with this level of reliability were first certified as ETOPS (Extended-Range Twin Engine Operation) in 1985.

ETOPS have to earn their stripes

In order to obtain an ETOPS certification, however, it was not sufficient for the operator simply to add such an aircraft type to the fleet via purchase. The government legislation will gradually increase the ETOPS certification rating depending on how reliably the airline is shown to operate this type of aircraft. And this also depends on which engines are installed. The aircraft manufacturers usually give the operator a choice out of several engine manufacturers.

Modern aircraft such as the A380 or the B747-8 are given ETOPS approvals of 330 minutes or more starting from their maiden flight. With the birth of the modern twin-engine Boeing 777/ 787 and Airbus A330/ A350, ETOPS certification was directly included in the development process. They have a high level of technical redundancy and have been certified accordingly by the authorities.

Prerequisites for ETOPS

In order to be considered for ETOPS, flight planning must meet a variety of criteria. Special approach procedures, meteorological instrumentation, fire-fighters and other facilities are mandatory. All pilots are specially trained for ETOPS, and every area that is served by ETOPS has its own procedures in the event of an emergency, such as engine failure or other problems. This also applies, for example, to the passengers’ accommodation and how they get from the alternative airport to their destination.

Weather minimums

For ETOPS, certain safety buffers must be applied regarding the weather minimums of airports. If the weather forecast is too bad, the dispatcher must use another airport for planning. When airborne, the pilots have to inform themselves about the current weather conditions before approaching. No buffers will be added here, the airport must be approachable.

Entry, exit and equal time point

When entering and leaving the ETOPS area in the air, we refer to this respectively as entry and exit point. These are always located at the end of the next 60-minute circle of a reachable airport. If the jet is more than 60 minutes away from one of these places, it has “gone ETOPS”, as pilots say in technical jargon. You have not reached an EXIT point until you are again able to reach a 60-minute circle. This means that there can be several ETOPS areas en route after leaving an hour circle again. Within the ETOPS area there is also a so-called ETP (equal time point). This point has previously been calculated exactly taking into account the wind. It describes the point on the route where both ETOPS airports can be reached at the same time. If you fly beyond this point, you would fly on to the next ETOPS airport instead of turning around. The pilots can directly visualize all these points in different ways on the cockpit instruments.

ETOPS fuel

ETOPS must be taken into account concerning the fuel reserves. If the last ETOPS alternative airport is further away than the destination airport to be approached, i.e. the fuel requirement for such an alternate landing is higher than the remaining residual fuel, so-called ETOPS fuel must be added. This ensures a safe alternative landing at all times, even if a problem occurs at the worst possible time. Modern twin-engine aircraft such as the Boeing 777/ 787 or Airbus A350 can even fly over three hours with just one engine to their next ETOPS alternate airport.

So the next time you fly to the USA or Asia, it’s very likely that you’re on an ETOPS flight. If you want to know more about flying over the Atlantic or theplanning of aircraft fuel, we recommend our articles.

You can also learn more about ETOPS in this video:

Titelbild © Pixabay Skeeze

by Tim Takeoff

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