CharlieDeltaUK
I am sure an expert will come along shortly and expand but put very simply, ETOPS stands for either Extended-range Twin-engine Operational Performance Standards or Extended Operations, depending who you speak to.
It is a set of rules that enable twin engined jets to fly over places that were only accessible to 4 engined jets. The ETOPS rules are there to satisfy the FAA requirement that you can reach an alternate airport in the case of an emergency diversion.
This effectively enabled twins to cross the Atlantic.( Because the 60 minute away airport could be at Greenland, then at Great Britain etc)
There are different levels of ETOPS certification, each allowing aircraft to fly on routes that are a certain amount of flying time away from the nearest airport. For example, if an aircraft is certified for 180 minutes, it is permitted to fly any route, as long as it is always within 180 minutes flying time to the nearest airport. ETOPS operation has no direct correlation to water or distance over water. It refers to single-engine flight times between diversion airfields, regardless as to whether such fields are separated by water or land.
Advances in technology ( 777 and hi bypass turbofans) meant that a twin can now safely cross the pacific. Thus there is ETOPS 120. This means that instead of 60 minutes airports can now be 120 minutes away.
ETOPS 180 and ETOPS 207 are also available. ETOPS 207 is only available to the 777.
Now ETOPS certified aircraft have to have some extra redundancy. Such as be able to light the APU mid flight, have more capable fire suppression systems etc. They are also higher maintained.
I would prefer an expert to comment on the elephant in the room.
Last edited by Rail Engineer; 9th Jan 2013 at 18:12.