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ETOPS

Old 9th Jun 2011, 15:23
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ETOPS

If a twin engined aircraft is flying more than 60 minutes away from a suitable operational airfield, with this time being calculated for a single engine operation in still air conditions, then the aircraft is flying ETOPS.

Am I right in saying if a two engine aircraft takes off and now I shutdown the other engine and we fly for 60 minutes the distance that I cover would be the limit for that aircraft, if it crosses this limit this aircraft is now flying ETOPS.

Is this the correct interpretation !!
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Old 9th Jun 2011, 15:51
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Could you explain your question please?
Why would you continue flying away from the airfield you took off from on one engine?

The ETOPS distance is a set number, which is part of the ETOPS certification.
For instance, in my company for the B777 it is 400 NM.

So 180 ETOPS is maximum 1200 NM from an adequate airport.
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Old 9th Jun 2011, 16:00
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How is the 400nm calculated?
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Old 9th Jun 2011, 17:16
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I'll try to make it as simple as possible:

Originally Posted by granard
Am I right in saying if a two engine aircraft takes off and now I shutdown the other engine and we fly for 60 minutes the distance that I cover would be the limit for that aircraft, if it crosses this limit this aircraft is now flying ETOPS.

Is this the correct interpretation !!
Not exactly.

Before flying ETOPS, the aircraft must be ETOPS certified by the manufacturer.
The operator who wishes to operate under ETOPS must go through an approval with its regulatory authorities.

Part of this approval process, a 60 min maximum diversion distance has to be determined (i.e. approved one-engine inoperative cruise speed)
There are different methods to calculate it....

Once this distance has been calculated and approved, you will be flying ETOPS each time your route takes you further than this 60 min max diversion distance from an ADEQUATE airport.

That 60 min distance is fixed under the ETOPS approval and can vary from one operator to another.

In my company, it is 420 NM for all Airbus fleets for commonality reasons.
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Old 9th Jun 2011, 17:54
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Thanks for the response.

How is this 400nm calculate?

Is it by as I said at the start flying the aircraft on one engine at cruise speed for 1 hour and see what distance this covers.

Now for that particular aircraft it would be 400nm.
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Old 9th Jun 2011, 18:52
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Not by actually flying the aircraft, but by using the certified single engine performance data. The single engine cruise speed is selected by the airline (who then must allow for the required fuel flow in their critical point calculations).
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Old 28th Jul 2015, 08:53
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Originally Posted by granard View Post
How is the 400nm calculated?
Boeing has a Flight Planning & Performance Manual(FPPM) with information for ETOPS. A chart using MCT is available with distances for 1 hour based on various weights or another performance chart could be used.
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Old 28th Jul 2015, 09:05
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Granard,


Frustrating isn't it when no one answers your question, so here goes,


Threshold distance (ETOPS) is ;


Maximum distance from an adequate aerodrome for twin engine aeroplane without ETOPS approval. Based on ;


1) Diversion after engine failure
2) Take off at MTOW and gross weight after one hour of flight time
3) Mmo/Vmo speed schedule
4) zero wind
5) ISA conditions


Hope that clears it up
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Old 29th Jul 2015, 02:48
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The calculated distance will vary depending on what speed schedule the operator chooses to use. A faster speed will give a greater distance, but will mean a lower maximum altitude & therefore may give terrain clearance problems, depending on the area of operation for that particular operator. The distance obtained from these calculations by the operator will then need to be approved by the regulator.

Once the operator has the distance approved this becomes the EDTO threshold distance (ETOPS is now referred to as this - Extended Diversion Time Operations). This figure does not change from day to day, as it is a theoretical figure. Therefore the actual time to fly from this point on one engine on any particular day may be greater or less than 1 hour due to wind & the actual speed used on that particular day. The reason I say 'the actual speed used on that particular day' is because you are not obliged to use the nominated speed that was used for the regulatory approval process. On the day you can fly what ever speed you feel appropriate. Just don't run out of fuel!

So this statement -

If a twin engined aircraft is flying more than 60 minutes away from a suitable operational airfield, with this time being calculated for a single engine operation in still air conditions, then the aircraft is flying ETOPS.
is incorrect. The aircraft is EDTO once it passes the EDTO threshold distance in the operators manual. Most use the fix page to put the EDTO threshold distance in & therefore have the threshold distance displayed on the ND as a circle around the EDTO adequate airport/s.

It can be a little confusing as the EDTO threshold is referred to as a time for convenience, when in fact it is a distance. Time & speed are simply used to calculate it. To further complicate matters, the various EDTO times (such as 60, 120, 180, 207, etc) can be calculated using different speeds by the operator, which means that the distances for these various EDTO times are not multiples of each other. For example, my company uses 431nm for their EDTO threshold distance (60 minutes) & 823nm for their 120 minute distance.

Last edited by Oakape; 29th Jul 2015 at 03:04.
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Old 29th Jul 2015, 09:26
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Oakape.
ETOPS is still ETOPS in Europe.
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Old 29th Jul 2015, 20:57
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ICAO has adopted the terminology EDTO, but accepts that some authorities still choose to use the old term ETOPS. EASA & FAA are the two big players that still use the term ETOPS. Both EDTO & ETOPS are basically referring to the same thing. Page 11 explains.

http://www.icao.int/SAM/Documents/20...%93Summary.pdf

The main thing with EDTO is that three & four engine aircraft are now included in the requirements.
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Old 30th Jul 2015, 00:03
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ETOPs is still the 'official' FAA acronym, but it's become somewhat meaningless since it no longer applies exclusively to "Twin" engined aircraft per the latest FARs (gory details in "Appendix K").

So, in typical government newspeak, ETOPs no long stands for "Extended Twin OPerationS, it's now ExTended OPerations Some of you that have been around the industry as long as I have may recall the original acronym - EROPs (Extended Range OPerations) but that was too logical so it got changed to ETOPs

EDTO makes a lot more sense given the current meaning of the rules.
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Old 30th Jul 2015, 06:21
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And I always thought that ETOPs meant "engines turn or passengers swim"
What does EDTO mean? "Engines die, time outstanding" ?
Other definition suggestions are welcome.
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Old 30th Jul 2015, 06:53
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part of the aircraft ETOPS certification is also a lot strickter maintenance regime, with rules like both engines cannot be changed within a certain flight time period of each other etc etc.
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Old 30th Jul 2015, 10:07
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What does any of that have to do with the posters question ?
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Old 30th Jul 2015, 22:57
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from the original post, it appeared the person asking the question doesnt quite understand the meaning of ETOPs operations, their initial assumption was it was a time based thing with regards to the aircraft flightpath, so, some of the following responses highlight the fact that ETOPS is a certification issues, with numerous requirements, none of which have anything to do with flight times past certain points. so, in effect, answering the question, and hopefully educating the original poster in what ETOPs essentially means.
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Old 30th Jul 2015, 23:47
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And the original post was from 2011. They probably have their answer by now!
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Old 5th Aug 2015, 06:24
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EROPS, ETDO or ETOPS. Does it matter? Jesus, some overpaid and under worked desk job hairsplitting idiot will soon probably re-invent Weight and Balance, and come up with something as meaningless (and unmeasurable) connected with Mass!
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Old 10th Aug 2015, 12:07
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Granard, you won't manage to understand the whole ETOPS thing by posting this question. Have a good read at all the stuff you have in your OM, FCOM and training docs from your airline, which are not as clear as they should, usually, then come here for clarification. It is a very interesting subject, actually.
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