ETOPS Explained- twin engine planes over long oceans.

 

ETOPS Explained

A note to the reader: I do not own any images that are referred to in this article. All sources are mentioned. As an aviation enthusiast, I have written this article from my point of view on ETOPS. Some of the readers might not be interested, but as you read on, I guarantee you, it will be. This article is completely based on the ETOPS issued by the FAA in the early 60’s in the United States of America.

 

“It’ll be a cold day in hell before I let twins fly long-haul over-water routes.”

Those were the words of Lynn Helms—administrator of the Federal Aviation Administration during the Reagan administration.

-Lynn Helms (Source: Wikipedia)

 

At the time, no commercial airplane with two engines was allowed to fly anywhere farther than 60 minutes from a diversion airport. The belief was that, if one engine failed, the other could only safely fly the plane for about an hour, but this rule severely limited what smaller planes could do. On North Atlantic routes like New York to London, twin-engine planes could only fly inside the green lines: 

 

 

but a direct route looked like this:

- (Source: Wendover Productions)

 

The options were to either fly a twin-engine plane on an inefficient route or fly an inefficient three or four engine planes. There was no place for long-and-skinny routes between smaller cities using smaller planes since airline couldn’t legally fly those smaller planes. This one simple rule changed the very way airplanes were built. Now, in the 60’s, this 60-minute regulation only applied to planes with two engines. Of course, aircraft manufacturers could build quad-engine jets but those had to be huge for airlines to make their money’s worth with their high fuel consumption. The 747’s of the time could carry more than 400 passengers.

-An old picture of the Boeing 747-200 (Source: SimpleFlying)

They could therefore only fly on super high-demand routes like New York to London to have any hope of being full. In order to start flying more convenient non-stop routes from smaller markets, planes had to get smaller while still being legally allowed to hop the ocean. That’s where trijets came into play. With three engines, these planes weren’t subject to the same 60-minute regulation as twinjets. They could easily fly any transatlantic route. That’s why in the 70s or 80s, the long-haul jets you’d see at airports were, for the most part, either 747’s or trijets like the DC-10.

-A McDonnell Douglas DC-10 departing from Chicago Intl. (Source: TravelUpdate)

 

This 60-minute regulation was inconvenient for Atlantic Crossings, but in the Pacific, it actually changed how Hawaii developed. There are zero diversion airports between California and Hawaii so the route isn’t even close to covered under the 60-minute rule. As a result, airlines could only fly huge planes between the mainland and Hawaii which meant that planes could pretty much only fly to Honolulu.

-A map of California and Hawaii (to scale) (Source: Google Maps)

 

There was virtually no service between the other islands and the mainland which meant the other islands were severely isolated. That’s part of the reason why the tourism industry only picked up on the other islands in recent decades. Luckily, change was coming. The 60-minute rule originated from the days of piston driven propeller aircraft. With these, it was far more common for engines to just stop working mid-flight. That’s why there were contingency engines.

-An old piston aircraft. (Source: Wikipedia)

The regulations just didn’t adapt to the increased reliability of jet engines. Statistically*, for every failure of a jet engine, there are 117 piston engine failures. Once the jet age rolled in, engine failure just wasn’t as much of a concern, so, in 1985, the FAA begrudgingly granted permission to Trans World Airlines to fly their twin-engine Boeing 767 direct between Boston and Paris—a route taking it up to 120 minutes away from diversion airports.

 

-Trans World Boeing 767 (Source: Unknown)

This was the first example of a brand-new FAA certification called ETOPS— “Extended-range Twin-engine Operational Performance Standards,” or more colloquially, “Engines Turn Or Passengers Swim.” Before an airline can fly a long over-water route, they have to buy a plane with what’s known as an ETOPS type rating. For example, the 767—the first plane to get an ETOPS certification —has a type rating of

*Statistics by The Federal Aviation Administration, USA

180 minutes meaning it can fly anywhere as long as its 180 minutes from a diversion airport. But just because a plane has a type rating doesn’t mean an airline can fly it ETOPS. They have to have a special maintenance plan, a special flight crew, special cabin crew, special dispatchers, special fuel quantities, etc. just because there’s a runway, doesn’t mean that a plane can safely divert since the emergency doesn’t end once the plane lands. Now, because of the solid engine reliability, numerous redundancies, and well-designed passenger recovery plans, airlines and airplanes can now receive insane ETOPS certifications. The 787 Dreamliner, has a type rating of 330 minutes. That means it can fly up to 5.5 hours away from a diversion airport.

 

 

-A brand new Boeing 787-10 (Source: Sam Chui)

 

Certain routes over long-ocean stretches in the southern hemisphere was theoretically possible in the past with four engine planes but were economically impossible since airlines could never fill the large planes on the low-demand city pairs like Melbourne to Santiago. With the ETOPS 330 certification, LATAM Airlines can fly their small 787 economically on this relatively low-demand route across the South Pacific. The Airbus a350 is even rated for ETOPS 370 —it can fly 6 hours and 10 minutes away from diversion airports.

This plane can therefore fly everywhere on earth except directly over the South Pole. Because of this simple rule change, three and four engine planes are largely a relic of the past. Boeing and Airbus’ largest jets are both their only four engine planes in production—the 747 and a380. Nearly all North Atlantic traffic today is on twin-engine planes as smaller and smaller planes get ETOPS certifications. Air Canada, for example, flies their tiny 120-passenger Airbus a319 with ETOPS certification daily between St Johns Airport and London Heathrow. British Airways even sends the even smaller a318 between New York and London City Airport. These routes would have been unimaginable 30 years ago but the reliability of the airplanes of today mean we need not fear flying small planes over big oceans.

 

 

-Written by: Samarth Sathya Karthik