Oct 29
ETOPS: Unlimited Trustworthiness
The ETOPS (Extended-range Twin-engine Operational Performance Standards) defines the twin-engine aircrafts requirements to operate flights where the nearest enroute alternative airfield is further than 60 minutes.
At the beginning of commercial aviation, because of the lack of regulations concerning alternative airfields further than 60 minutes, the air carriers started putting pressure on Aviation Administrations to be modified, in order to be able to operate transatlantic routes with twin-engine. Because of that, ICAO and the FAA drawn up a new reguation that allowed to operate those routes.
Nowadays, there are several ETOPS ratings depending on some parameters. These parameters are including the engines and systems’ reliability, crew training and ratings, manteinance and so on.
Author Andrés Meneses
These are the different ETOPS ratings issued these days by Aeronautical Authorities:
- ETOPS-75
- ETOPS-90
- ETOPS-120/138 (138 minuts is a 15% plus 120 minuts, in order to cover a little part of the Atlantic Ocean, not covered with ETOPS-120)
- ETOPS-180/207
An ETOPS rating is gradual. That means if you want to reach ETOPS-120 rating, first of all the aircraft must have reached the ETOPS-75 rating (with 200 sectors with 98% relieability), then the ETOPS-90 rating (with 300 sectors with 98% reliability), and finally the ETOPS-120. For example, in order to achieve ETOPS-120 rating, the airplane must prove less than 0.05 per mil in-flight shut-down. That means, flying 20.000 flights there’s only one in-flight shut-down (obviously, an airplane does not achieve 20.000 routes in its life).
There’s a tremendous application called Great Circle Mapper where you can compute each ETOPS rating maximum range around the earth.
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[...] aircrafts operating these flights (usually big ones) must have the ETOPS rating, explained in other post. That is because, the nearest alternative airport when flying above the atlantic is 180 minutes [...]
The Airbus A380. I believe this aircraft has an ETOPS rating due to the lack of components mounted on the two outer engines gearboxes. Engines No.1 & No.4 had many if not all components removed from the engine gearboxes to reduce weight.
The A380 must have an ETOPS rating based on its performance (including engines of course). As a matter of fact, as you can see in the picture below (check out the throttles levers), Airbus didn’t install reverses on engine num 1 and num 4.
http://cdn-www.airliners.net/aviation-photos/photos/9/5/1/1764159.jpg
If the A380 lost number 1 & 4 engines they would be in trouble with no thrust reverse for landing. It would need a very long strip to pull up and would probably burst tyres during landing.
I wonder how many people know these facts?
I personally have been in the aircraft; specifically the airline industry for over 42 years (retired now) and I worry about actually flying on the A380!
Correction. If the A380 lost Number 2 & Number 3 Engines they would be in trouble. No thrust reverse for landing.
While on the subjest of ETOPS, when a A380 flies between Sydney Australia to the USA & vice visa, how does ETOPS effect it actual route accross the Pacific Ocean compared to a Boeing 747-400 or 747-400ER?