ETOPS, The Bane of Twin-Engine Oceanic Travel
- Tushar B.
- Feb 3, 2019
- 2 min read
A long time ago (Specifically the 1960s) the FAA imposed a regulation on Twin-Engine commercial aircraft restricting where they could fly. The law stated that they could only fly up to 60 minutes away from the nearest diversionary airport at any given point in time, making transatlantic and transpacific flights nearly impossible.
The rationale behind this law was that if one engine failed, the other engine could only safely fly the plane for one hour; meaning the plane had to be less than an hour away from the nearest safe runway. But this law had been created under the assumption that engine failures were going to be common in commercial aviation. That simply was not the case. With older turboprop engines failure mid-flight had been relatively common, but with more modern turbojet engines this didn't happen. According to Steven E. Scates, a former US Army Aviator, "for every turbine engine experiencing a failure, 117 piston engines will have failed."
Because of these and other advancements in safety, the FAA finally allowed certain twins to fly more then 60 minutes from land in 1985. The first airline and plane to gain these privileges was Trans World Airline's 767 flying from Boston to Paris. This route took it 120 minutes away from diversion airports and started a new certification airlines and planes could get:
ETOPS.
ETOPS, or Extended-range Twin-Engine Operational Performance Standards, was a way for regulations to keep up with the increasing safety of long haul flights. If an aircraft had enough safety measures, redundancy measures, and reliable engines they could get an ETOPS rating. These ratings were relatively conservative at first, ranging from 120 to 180 minutes, but modern safety measures have made ratings go insanely high. The 787 Dreamliner, for example has a rating of 330 minutes, and the most recent 767s have ratings up to 380 minutes. This can take them almost anywhere on earth (with the notable exception of Antarctica). It has allowed for "long and skinny" routes that previously weren't profitable, since airlines had to fly larger planes for them. Aircraft could now fly small twin-engined planes on these routes, increasing their chances of filling the plane up, and increasing the chances of making a profit.
(Image of X-35B STOVL Propulsion System from the Steven F. Udvar-Hazy Center)