Etops

[767bill]

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

[Rainboe]

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.

[XPMorten]

ETOPS = Engine Turns Or Passengers Swim :ok:
(passenger perspective)

M

[767bill]

Thanks Morten, Rainboe. At least I now know what it stands for...

[Hunter58]

767bill

go to the FAA homepage and check for advisory circular 120-42A.

[pjumbo]

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

[tired]

pjumbo - I think you'll find that ETOPS is about a lot more than just fuel. System redundancy springs to mind for starters.

t

[pjumbo]

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'

[TR4A]

ETOPS = Engine Turns Or Passengers Swim
(passenger perspective)

METOPS = Engine Turns Or Packages Sink
(Cargo perspective)

[tired]

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.

[MrBernoulli]

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!

[767bill]

Thanks for the above!

[BGQ]

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.

:8 :8

[Old Smokey]

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

[DCDriver]

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".

[gashcan]

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.

[Old Smokey]

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 -
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
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

[gashcan]

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?

[BGQ]

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.



:) :) :)

[MarkD]

Old Smokey

why would an A380 *alternate* be any further than a B744 alternate?

[barit1]

From an "emergency" standpoint the A380 may be able to use a 747-capable field, but ground handling might be a near-disaster...

[DCDriver]

Old Smokey, I take your point about the 747 CFS

BGQ, it certainly is! It was always against my religion to do flights such as yours on less than 3 engines and with a F/E!

rgds, DCD

[Old Smokey]

OK BGQ, 10 out of 10, go to the top of the class. You've described the one situation where being ETOPS costs more fuel, that is, where the track must deviate from Great Circle to remain within ETOPS coverage of en-route Suitable/Acceptable/Adequate airports. That will, of course, cost more fuel.

It still remains that contingency fuel for Depressurisation / Engine out remains the same for all transport category aircraft, whether they be ETOPS or not.

Yes gashcan, Depress/Eng Inop fuel is mandated by the regulator when operating in all areas, regardless of the number of engines. The applicable reserves will invariably be specified in the operating company's fuel policy, which must be approved by the regulatory authority as required for the AOC. This covers (for any aircraft) the situation that you describe - "1.5 hrs from destination and the diversion is 2 hours do you have sufficient fuel?"

Of course, it is also a common sense requirement.

Good topic, interesting replies here, getting away from the usual "What is ETOPS" question.

Regards,

Old Smokey

[BGQ]

Old smokey,

While the ETOPs fuel is greater than the great circle fuel, in the case described, the engine out depressurised fuel in the last sector requires more gas than the increased fuel load for flying the ETOPS route and that and is the limiting factor.

It mostly depends upon the distance apart of the available ETP airfields and the winds at 10,000 ft.

Pilots flying these sectors are always concious of remaining within the required range circle and having the gas to get there single engine depressurised.

For the B763 you have been correct all along that engine out depressurised (flown single engine with TAS 370kts at 10,000ft ) fuel is the more limiting fuel scenario than the ETOPs fuel (flown on one engine pressurised at 415 knots TAS at whatever altitude you can).

I imagine that the same situation exists for all other extended range twins. That's why my first statement that the bottom line of ETOPS is staying within the appropriate range circle of an adequate and suitable airfield.

I agree it has been interesting and thought provoking. Good topic.

:\

[flightleader]

With the flight you mentioned, was there a hefty penalty on the payload in order to carry the fuel required?

I've done flights from Paris to KUL in the 777-200 some 6 years ago. There was a consistantly 4500kgs of payload had to be offloaded in order to carry the required fuel for ETOPS over bay of Bengal. Soon, the company opted for a route a little further up north to avoid ETOPS, and took all payload (at MTOW)we can carry from Paris.

Great topic.:ok:

[BGQ]

Flightleader

We always seem to be able to carry the pax and the cargo on the Tahiti-LAX sector in the 763 (about 8 1/2 hrs). We get hit on payload on the Fiji - Lax sector (closer to 11 1/2 hrs) but in both cases the single engine depressurised fuel requirement is more punishing than the ETOPS fuel.

In the last part of the flight we are using HNL and LAX as the enroute alternates.

In both cases a large deviatition north of the great circle track is required to stay within the 180mins range circles.

[flightleader]

BGQ

Thanks for the reply. As I 'm not familiar with that part of the world, I would appreciate if you could elaborate more.

From AKL (or SYD for the matter) going eastward, would you be using AKL and Tahiti as enroute alternate or you have some other airfield i between?

In term of airfield,are there any different choices for B767 and B747? Would the B747 have to be routed further up north?

On the 767,when you arrive LAX, what is the fuel onboard like? Is it a lot more than you need for your destination alternate?

Thanks.

[mutt]

BCQ,

I'm curious, do you operate under FAR121? Do you use tailnumber flight planning?

Mutt

[BGQ]

New Zealand CAA Rules which are pretty much aligned to FAA Rules.

Air NZ was one of the early ETOPS operators and probably operates over some of the most limiting sectors worldwide.

[mutt]

Thanks for that, as to my 2nd question, do you use tail number flight planning or a fleet average??

Cheers

Mutt

[BGQ]

Tail Number, each aircraft has it's own specific performance continuously calculated. In Air NZ we call it PDA - performance deterioration allowance:8

[OVERTALK]

A couple of years back a (United?) 777 (or was it a 763?) did a longest ever overwater single-engine transit into Hawaii (Hilo?).
.
Was that a/c Rolls-Royce equipped?
.
Anybody have a reference (or link) or other details for it?

[Tim Zukas]

From AKL (or SYD for the matter) going eastward, would you be using AKL and Tahiti as enroute alternate or you have some other airfield i between?


If Apia (Faleolo) and Tahiti and Kona are all available and suitable, then 1200 nm ETOPS will cover that triangle okay, and the great circle from Auckland to California is never more than 1200 nm from Hilo or LAX.

On Airliners.net somebody asked about nonstop AKL-ORD or AKL-JFK, and it turned out the dogleg to stay within 1200 nm added less than 100 nm to the trip, compared to the great circle. The critical point is the Hilo-LAX equipoint-- you can fly direct from AKL to there, then direct from there to destination.

But 1200 nm is conservative?

By the way-- Is the 10000-ft runway on San Nicolas Island out of the question as an allowed alternate?

[TheShadow]

The longest ETOPS-related emergency flight diversion (192 min. under one engine power) was conducted on a United Airlines' Boeing 777-200ER, carrying 255 passengers, on March 17, 2003 over the southern Pacific ocean.
UA842 from AKL to LAX on 17.March 2003 was forced to fly a 190min
diversion on 1 engine over the Pacific. The captain had to shut
down the number 2 engine (PW4090) because the oil pressure
dropped dramatically. The aircraft (N780UA) was diverted to KOA (Kona Intl)and
it landed safely. Indications are that the engine may have
suffered a bearing failure. UA says that the time on 1 engine
was just over 3 hours, but the FAA says it was 190 to 193min.

[smudgethecat]

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"ETOPS is all about fuel" your having a "giraffe"........ surely?

[78deg]

ETOPS is all about rules to enforce airmanship