It’s very normal for us to fly over and across oceans, however it hasn’t always been like this. These flights are now regulated by something called ETOPS.
These rules regulate which aircraft can fly certain routes. Extended Range Twin-engine OPerationS (ETOPS) regulation states which aircaft types can fly long range routes that don’t have an alternate airport within 60 minutes at any given time.
What is an Alternate Airport?
An alternate airports are different airfields than the original destination. Of course these airports are come into play only when there is an emergency onboard the flight.
In these cases the pilots will decide to divert to the closest alternate airport to safely land the plane.
Why Does ETOPS Apply to Twin Engine Airplanes?
The reason is very simple. And of course it’s due to the number of engines propelling the plane. Less engines means less redundancy. In the unlikely case that an engine has an issue during a flight it can have a much bigger impact on a twin engine aircraft than on a 4 engined plane.
For example if an engine flames out on a 747, there will still be 3 operating. This is pretty big safety margin, as many 4 engined aircraft that manage to reach thier alternate airport even with only 2 engines working.
In lamer terms it means that they could afford to lose even another engine and still be safe.
On the other hand if a twin engine plane, such as a 787 or an A350, loses power from an engine they have lost already 50% of power. Wich of course means less margin for error. If they were to lose another one they’d be completely out of power.
A Short Story About ETOPS
Limitations on aricraft with less than 4 engines have been in place ever since aviation’s birth. But as technological advancements significantly improved the efficiency of planes, airlines pushed for less stringent regulations. However until 1964 only 4 engined aircraft could make the very busy crossing between Europe and the US.
1964 however is the year that revolutionized aviation and started opening the door to modern aviation. In fact, until then as we said only 4 engined aircrafts could make these flights. But from there on the minimum of engines required engines was lowered to 3.
The Rise of 3 Engined Planes
As soon as it became clear that even 3 engined aircrafts could make these flights the aviation world assisted to the rise a new breed of planes. In my opinion some of the most beautiful airplane designs were created in this era.
Lockheed and McDonnell Douglas were the main players of the tri-jet era. These two constructors created respectively the iconic:
- Lockheed L-1011
The 2 planes due to their extremely innovative designs had some issues and unfortunately did suffer accidents. The whole concept of the tri-jet revolved around a design with 2 traditional turbofan engines under the wings. A third unit was incorporated in the vertical stabilizer in the tail of the plane. This pushed the engineers to reduce the size of the rudder. This particular design caused these planes to be harder to control than other traditional planes.
Lookheed did roll out udated versions of their L-1011, but never lanched a second model. MD on the other hand later launched the MD-11 which featured a so called glass cockpit, making it possible to fly with only 2 pilots. This is my opinion is the most beautiful aircraft ever created. But that’s just my opinion.
The Fall of 3 Engined Planes
The era of this design didn’t last all that long. In fact, in 1985 the modern ETOPS regulations were lanched, where even certain twin engine aircraft types became eligible to fly these special routes. That same year a TWA (Trans World Airlnes) twin engined 767-200 made crossed over the Atlantic Ocean, flying from Boston to Paris.
This was the end of the Tri-Jet era. More and more efficient twin engine planes were rolled out thereafter and the Dc-10s MD-11s and L-1011 slowly dissapeared from the skies. Nowadays there aren’t any of these aircraft types left flying passenger routes. It’s more likely that you’ll see one of these airliners flying cargo routes. For instance, there are still many MD-11s present in the UPS and FedEx fleets.