Etops
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Etops
Can someone explain to me ETOPS and the safety implications of twin engine transatlanic flight operations, for example action required if one of the two engines malfunctioned. My interest is part from a passenger perspective and part from the point of view of someone who is involved in aviation.
Thanks.
Bill
Thanks.
Bill
Warning Toxic!
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I think rather than just ask and expect someone to go through the considerable time and trouble of trying to answer a rather broad question, you take the trouble yourself to do a search of ETOPs and wade through yourself! You will be thoroughly educated to your satisfaction.
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ETOPS is all about FUEL. Making sure, at the planning stage, that you have enough fuel on board at all times, for the worst case scenario, (Critical Fuel Scenario).
For the A330 aircraft, this is an engine failure and pressurisation failure at the same time, occuring at the Critical Fuel Point (a point on the route where there is the least amount of fuel left on board, which is available to cover the Critical Fuel Scenario). This would require an immediate descent, followed by a diversion at FL 100 to a suitable airport.
Clearly, there is much more to the subject than the above. But hope this gives you a basic idea.
Happy flying..........
pjumbo
For the A330 aircraft, this is an engine failure and pressurisation failure at the same time, occuring at the Critical Fuel Point (a point on the route where there is the least amount of fuel left on board, which is available to cover the Critical Fuel Scenario). This would require an immediate descent, followed by a diversion at FL 100 to a suitable airport.
Clearly, there is much more to the subject than the above. But hope this gives you a basic idea.
Happy flying..........
pjumbo
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Hi again.....
Yes, you're quite correct 'Tired', there is a great deal more to ETOPS than 'just' fuel - as I mentioned in the last but one line.
Perhaps though, it could be stated that the 'bottom line' (not the bottom line in my last post!) is FUEL.
In other words, assuming the aircraft is cleared for ETOPS (i.e. it has the required system redundancy as you correctly mention, plus ALL the other multitude of requirements), it is then the responsibility of the crew to ensure that sufficient fuel is loaded
before departure, to achieve the worst case scenario should it occur during the flight.
Anyone with additional info, please continue, to help '767bill' with his question.
Cheers..........'pjumbo'
Yes, you're quite correct 'Tired', there is a great deal more to ETOPS than 'just' fuel - as I mentioned in the last but one line.
Perhaps though, it could be stated that the 'bottom line' (not the bottom line in my last post!) is FUEL.
In other words, assuming the aircraft is cleared for ETOPS (i.e. it has the required system redundancy as you correctly mention, plus ALL the other multitude of requirements), it is then the responsibility of the crew to ensure that sufficient fuel is loaded
before departure, to achieve the worst case scenario should it occur during the flight.
Anyone with additional info, please continue, to help '767bill' with his question.
Cheers..........'pjumbo'
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pjumbo - not trying to have a go at you or anything, but I would like to think that the bottom line on any flight, not just ETOPS, is having enough fuel to cover the worst-case scenario. The thing that makes ETOPs different from 3- or 4-engined long haul is precisely "system redundancy and all the other multitude of requirements".
767bill - the JAA, like the FAA, also publishes screeds and screeds of stuff on ETOPS - I don't have a reference off the top of my head, but if the FAA doc quoted above by hunter58 doesn't satisfy your curiosity then try the JAA's site.
767bill - the JAA, like the FAA, also publishes screeds and screeds of stuff on ETOPS - I don't have a reference off the top of my head, but if the FAA doc quoted above by hunter58 doesn't satisfy your curiosity then try the JAA's site.
767bill
Try reading this from the CAA website:
http://www.caa.co.uk/docs/33/CAP513.pdf
CAP 513 is a 228 kb download and deals with ETOPS!
Try reading this from the CAA website:
http://www.caa.co.uk/docs/33/CAP513.pdf
CAP 513 is a 228 kb download and deals with ETOPS!
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A lot of posts in here say that the bottom line is fuel..... not true.
The bottom line is that once airborne the aircraft must remain within the specified flight time (i.e. 120 min or 180mins etc) in still air at the proscribed speed (varies for each airplane and company) of an airfield that the airplane can land at.
Prior to departure there are a number of requirements regarding fuel, weather conditions and aerodrome suitability that must be met but they disappear once airborne where the first paragraph become the only requirement.
The bottom line is that once airborne the aircraft must remain within the specified flight time (i.e. 120 min or 180mins etc) in still air at the proscribed speed (varies for each airplane and company) of an airfield that the airplane can land at.
Prior to departure there are a number of requirements regarding fuel, weather conditions and aerodrome suitability that must be met but they disappear once airborne where the first paragraph become the only requirement.
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NORMAL operations is all about fuel, whether the aircraft has 1,2,3,4, or 67 engines, sufficient fuel must be carried to provide for normal flight to a suitable airport from any point en-route with normal reserves, and in the 2 usually nominated non-normal conditions of depressurisation or engine failure, to provide for flight to a suitable airport from any point en-route with reserves applicable to that condition (In this context, Suitable, Acceptable, and Adequate airports are merged to the one word - Suitable).
Normal operations for 2 engined Transport category aircraft are limited to a maximum of 60 minutes flight time from a Suitable airport in the 1 engine inoperative condition. If the aircraft has PROVEN back-up systems (Hydraulics, electrical supply etc), AND the In-Flight Shut-Down (IFSD) rate is statistically low and acceptable to the certifying authority, then the aircraft / operator MAY be approved for ETOPS operations.
I regularly operate ETOPS flights from Singapore to the U.K., and the ETOPS critical sector is a mere One and a half hours out of Singapore crossing the Bay of Bengal. At that point, if suffering an engine failure, I have about 12 hours of fuel remaining to cover a 2 hour flight to the ETOPS contingency airport. Fuel is definately NOT a factor for ETOPS.
Regards,
Old Smokey
Normal operations for 2 engined Transport category aircraft are limited to a maximum of 60 minutes flight time from a Suitable airport in the 1 engine inoperative condition. If the aircraft has PROVEN back-up systems (Hydraulics, electrical supply etc), AND the In-Flight Shut-Down (IFSD) rate is statistically low and acceptable to the certifying authority, then the aircraft / operator MAY be approved for ETOPS operations.
I regularly operate ETOPS flights from Singapore to the U.K., and the ETOPS critical sector is a mere One and a half hours out of Singapore crossing the Bay of Bengal. At that point, if suffering an engine failure, I have about 12 hours of fuel remaining to cover a 2 hour flight to the ETOPS contingency airport. Fuel is definately NOT a factor for ETOPS.
Regards,
Old Smokey
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Old Smokey,
"Fuel is definately NOT a factor for ETOPS."
...perhaps not on the sector you have illustrated.
Were you to operate certain other sectors over oceanic / wilderness areas, or the ERA's were closed at night, you would be constrained by the Critical Fuel Scenario (see above) and fuel most certainly would be a factor, and your plog would show many tonnes "ETOPS Additional Fuel".
"Fuel is definately NOT a factor for ETOPS."
...perhaps not on the sector you have illustrated.
Were you to operate certain other sectors over oceanic / wilderness areas, or the ERA's were closed at night, you would be constrained by the Critical Fuel Scenario (see above) and fuel most certainly would be a factor, and your plog would show many tonnes "ETOPS Additional Fuel".
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Old Smokey - you answered the question correctly -
"I have about 12 hours of fuel remaining to cover a 2 hour flight to the ETOPS contingency airport."
You have therefore complied with the requirement to carry sufficient fuel to divert to an en-route alternate under worst case conditions.
By the way, what fuel do you have to cover the ETOPs Critical Fuel Scenario on the return sector, when you have burnt most of your fuel en-route? If the ETOPs critical sector is about 1.5 hrs from destination and the diversion is 2 hours do you have sufficient fuel?
DCDriver is absolutely correct - many sectors over ocean, sparsley populated areas, or areas without Suitable Airports may (and frequently do) require considerable amounts of extra fuel.
Fuel may not be the only bottom line, but it's certainly one of the most important ones.
"I have about 12 hours of fuel remaining to cover a 2 hour flight to the ETOPS contingency airport."
You have therefore complied with the requirement to carry sufficient fuel to divert to an en-route alternate under worst case conditions.
By the way, what fuel do you have to cover the ETOPs Critical Fuel Scenario on the return sector, when you have burnt most of your fuel en-route? If the ETOPs critical sector is about 1.5 hrs from destination and the diversion is 2 hours do you have sufficient fuel?
DCDriver is absolutely correct - many sectors over ocean, sparsley populated areas, or areas without Suitable Airports may (and frequently do) require considerable amounts of extra fuel.
Fuel may not be the only bottom line, but it's certainly one of the most important ones.
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DCDriver,
I'll definately concede that additional fuel to cover ETOPS flight at the END of a flight is definately a factor, but the point that I was making was that ETOPS, per se, is not fuel related.
In the example you've given -
Most certainly you are correct, and what you quote applies to a 2, 3, or 4 engined aircraft, it does not apply to an ETOPS aircraft alone. On my last aircraft type, the B747, additional Depressurisation / Engine Inoperative fuel had to be carried in the circumstances that you describe, and the B747 is most decidedly NOT an ETOPS aircraft. What you speak of is normal contingency fuel for normal operations, be they ETOPS or not.
QUADRITOPS fuel for the A380 where the nearest suitable ERA may be thousands of miles away might be interesting.
Regards,
Old Smokey
I'll definately concede that additional fuel to cover ETOPS flight at the END of a flight is definately a factor, but the point that I was making was that ETOPS, per se, is not fuel related.
In the example you've given -
Were you to operate certain other sectors over oceanic / wilderness areas, or the ERA's were closed at night, you would be constrained by the Critical Fuel Scenario (see above) and fuel most certainly would be a factor
QUADRITOPS fuel for the A380 where the nearest suitable ERA may be thousands of miles away might be interesting.
Regards,
Old Smokey
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Saskatoon - that depends!
My company used the FL100 two-engine scenario as worst case for the B763, but FL100 single-engine as worst case for the A332.
However, I believe that at certain speeds, depending on engine type, FL100 two-engine is worst case for the 330!
Old Smokey- I'm not familiar with 3 or 4 eng LROPS - is Depress/Eng Inop fuel mandated by the regulator when operating in certain areas, or is it a company (or common sense!) requirement?
My company used the FL100 two-engine scenario as worst case for the B763, but FL100 single-engine as worst case for the A332.
However, I believe that at certain speeds, depending on engine type, FL100 two-engine is worst case for the 330!
Old Smokey- I'm not familiar with 3 or 4 eng LROPS - is Depress/Eng Inop fuel mandated by the regulator when operating in certain areas, or is it a company (or common sense!) requirement?
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Is trans pacific remote enough for you DCdriver ?
On a flight from Tahiti to Los Angeles the B763 uses a still air speed single engine etops of 415kts TAS. That means it must plan to stay within 1245nm of an adequate and suitable airfield. On this sector the flight has to deviate several hundred miles north of the direct track to comply with this requirement in the mid to latter stages of the flight. The airfields used are Hilo (when it's available) and Honolulu when it's not. Both are in the Hawaian group.
The critical fuel scenario on the B763 is single engine depressurised flight. i.e the ability to descend to 10,000 ft and fly on one engine from the equitime point to the alternate, have enough when you get there for an instrument approach overshoot and visual approach and landing plus 15 mins gas plus 5% contingency fuel and any PDA.
The critical fuel scenario described above will always be the limiting factor even if we ignored etops and were allowed to fly the great circle track between Tahiti and LAX. In fact more fuel would be required to cover this scenario as we would be further south of the etops track and thus further away from the enroute alternate. (Possibly 4 hours or so away on one engine.)
Thus fuel is a factor but not the bottomline of ETOPs. To comply with the regs my first statement posted is the bottomline.
On a flight from Tahiti to Los Angeles the B763 uses a still air speed single engine etops of 415kts TAS. That means it must plan to stay within 1245nm of an adequate and suitable airfield. On this sector the flight has to deviate several hundred miles north of the direct track to comply with this requirement in the mid to latter stages of the flight. The airfields used are Hilo (when it's available) and Honolulu when it's not. Both are in the Hawaian group.
The critical fuel scenario on the B763 is single engine depressurised flight. i.e the ability to descend to 10,000 ft and fly on one engine from the equitime point to the alternate, have enough when you get there for an instrument approach overshoot and visual approach and landing plus 15 mins gas plus 5% contingency fuel and any PDA.
The critical fuel scenario described above will always be the limiting factor even if we ignored etops and were allowed to fly the great circle track between Tahiti and LAX. In fact more fuel would be required to cover this scenario as we would be further south of the etops track and thus further away from the enroute alternate. (Possibly 4 hours or so away on one engine.)
Thus fuel is a factor but not the bottomline of ETOPs. To comply with the regs my first statement posted is the bottomline.