Airbus 380 loses engine, goes 5000 miles [Archive]

Jefferson Airplane

11th Nov 2013, 16:45

Aah, the hysterical chattering of the ignorant masses.

This is why aircraft are built with four engines. There is absolutely nothing unsafe about continuing on three engines. The big twins are certified to 207 minutes and more on ONE engine.

Consider the practicalities of a diversion at the time of the engine failure which, I believe, occurred about two hours after take-off:

1. A significant amount of fuel would have to be jettisoned
2. Hotel accommodation for 20+ crew and 450-500 passengers
3. Nothing less than a 24 -36 hour delay before replacement components could be sourced, shipped and installed

By continuing the flight, the company has 12 hours to formulate a recovery plan and position a replacement aircraft at the en-route alternate (in this case Kuwait).

The A380 completes a dramatic three-engine approach, lands and pax and crew transfer to the waiting aircraft and the mission is completed with minimum delay.

And in absolute safely.

Well done to the four professionals up front.

blind pew

11th Nov 2013, 16:55

Perhaps but the report on BA stated that an undamaged windmilling engine is certified for three hours...so who gives a "professional" pilot the authority to be a test pilot with pax on board?

Good Business Sense

11th Nov 2013, 16:59

Over the years, on more than one occasion, managed to log quite a bit of single engine jet time ...... with over 300 people down the back :8

Squawk7777

11th Nov 2013, 16:59

Ignorance on which side?

Reminds me of the EK 777 that suffered engine damage shortly after t/o from Moscow to DXB. No Warning, or Caution message, only two or three Advisory messages. The crew continued the flight, only to discover "more than just cosmetic damage" on the right (?) engine. Luckily, it didn't cause more harm.

There is absolutely nothing unsafe about continuing on three engines. The big twins are certified to 207 minutes and more on ONE engine.

Statements like these make me nervous, it is like the three monkeys that see, hear and speak no evil. No abnormal indications up front on the flight deck, nothing mentioned per SOPs, so life must be good...

Are we really just becoming robots?

White Knight

11th Nov 2013, 17:01

Perhaps but the report on BA stated that an undamaged windmilling engine is certified for three hours...so who gives a "professional" pilot the authority to be a test pilot with pax on board?

Because, my dear blind chap, there is NO limitation for the 380 with the 7270 engines with regards to windmilling. Just note the 'windmill' time in the tech log... So our 'professional' pilots are indeed being professional.

Bl00dy drama queens here:hmm::hmm:

Megaton

11th Nov 2013, 17:03

Squawk7777

Do you think we just have a quick look at the EICAS and decide whether to continue or not? Part of the fault diagnosis will be to discuss the failure with MAINTROL, determine if there's a history with the engine, ensure the continued viability of the remaining engines etc etc. I guess you've never flown a four-engined Boeing or read the Flight Continuation Policy associated with such aircraft?

White Knight

11th Nov 2013, 17:04

Statements like these make me nervous, it is like the three monkeys that see, hear and speak no evil. No abnormal indications up front on the flight deck, nothing mentioned per SOPs, so life must be good...

Perhaps because all of the abnormal indications on this paticular flight related to the number 4 engine only and it was that one that finally threw it's toys out...

I fail to see your logic. Three is still better than two - at least in my eyes when I'm crossing several thousand miles of ocean or mountain-chain!

BOAC

11th Nov 2013, 17:12

Gosh! 5000 miles on 3 - just think how far it could go on 2.....................:p

lomapaseo

11th Nov 2013, 17:15

I hate it when engines simply flame out as compared to tossing their cookies. Makes me think of contamination problems likely to affect all engines eventually.

Of course I wouldn't trust this report either :)

Jefferson Airplane

11th Nov 2013, 17:15

Are we really just becoming robots?

Squawk, Habibi you are shooting yourself in the foot.

Robots probably would have diverted immediately. The crew involved with this particular incident would have analysed the situation to some significant degree and consulted with MCC before committing to a decision.

The term we use is airmanship.

Lord Spandex Masher

11th Nov 2013, 17:18

Gosh! 5000 miles on 3 - just think how far it could go on 2.....................:p

Could've made Dubai, maybe. I'd have shut down another...

;)

White Knight

11th Nov 2013, 18:30

I hate it when engines simply flame out as compared to tossing their cookies. Makes me think of contamination problems likely to affect all engines eventually

As I said. All of the ECAM warnings involved only the number 4 engine which eventually flamed out 2 hours later... Fuel pump failure, so no, it didn't just flame out on a whim:hmm:

White Knight

11th Nov 2013, 18:31

Quote:
Originally Posted by BOAC
Gosh! 5000 miles on 3 - just think how far it could go on 2.....................

Could've made Dubai, maybe. I'd have shut down another...

Shut 'em all down and go anywhere you want as you'll be up there all day. Or was that Aer Lingus:D?

Squawk7777

11th Nov 2013, 19:28

Perhaps because all of the abnormal indications on this paticular flight related to the number 4 engine only and it was that one that finally threw it's toys out...

Do all those abnormal indications in the cockpit give you a complete overview of the situation? How can you be certain that there is not more to it? Let's look back a couple of months: Did the EK 777 crew (flight 132 (http://www.pprune.org/rumours-news/462459-article-ntsb-emirates-777-continued-flight-after-loud-bang-messages.html)) have an indication of the outside physical damage? The indications available on the flight deck do not necessarily reveal the entire situation. Continuing a flight because everything seems normal, does not mean that it is safe.

I fail to see your logic. Three is still better than two - at least in my eyes when I'm crossing several thousand miles of ocean or mountain-chain!

Flying on one engine isn't a big deal either! Or with partial landing gear. Just ask the crew of HL-3378. The authorities were so impressed by the captain's decision that they revoked his license (shortly before his retirement).

Airmanship. Where do you draw the line between operational need (better: pressure) and safety? One could also argue because a certain item is MEL'd that it is (still) safe.

Where's the attention to detail?

flarepilot

11th Nov 2013, 19:31

and I just posted the link. imagine if I had actually said something.

and what I would have said was: ;-)

helen-damnation

11th Nov 2013, 19:45

Do all those abnormal indications in the cockpit give you a complete overview of the situation? How can you be certain that there is not more to it? Let's look back a couple of months

Better still, lets look back 10 or 20 or 40 years and all those millions of flights that dangerously flew around with "normal" indications. Do all those NORMAL indications in the cockpit give you a COMPLETE overview of the situation?

You will never have a complete overview in the same way a medical check doesn't mean you will be fit to fly for a year.

As was said earlier, it's airmanship based on experience, information, 3rd party input.

Continuing a flight because everything seems normal, does not mean that it is safe. Better take the boat then :ugh:

Squawk7777

11th Nov 2013, 19:49

Another way of using ignorance as an excuse? Or give in to company pressure?

Oddly, what about your pet argument when it comes to EK132 that I previously mentioned? Or applying it to HL-3378? :ugh:

You will never have a complete overview in the same way a medical check doesn't mean you will be fit to fly for a year.

B-b-b-b-but you are trying to minimize the risk (aka safety) and pushing your luck does not make it safe. Planes have become more complex with more possibilities of failures. Just because something has been done like this 40 years ago, doesn't make it safe!

One only needs to recall those very dangerous days prior to the mandatory high-viz vest requirement! ;) :hmm:

Offchocks

11th Nov 2013, 21:04

I'm fairly sure that the decision would have been made with the help/ consultation of their engineering department. By that I mean the engineering department would have been receiving real time data on the health of the aircraft, this is usually a lot more detailed than what is presented to the pilots.

In 40 years I've never had an engine failure and may it be so for the next couple before I call it a day. If after ticking all the boxes, I would also continue on 3 engines if I thought it were safe.

barit1

11th Nov 2013, 21:18

It is most primitive to conceptualize safety (or risk) as a binary parameter; that is, something is either "safe" or "not safe". Lets not perpetuate this foolishness, eh?

In the regulatory and engineering world, risk is measured as an analog quantity - x events per 100 million hours, etc.

Obviously, one needs an experience base to make sense of this science.

barit1

11th Nov 2013, 21:30

I hate it when engines simply flame out as compared to tossing their cookies. Makes me think of contamination problems likely to affect all engines eventually.

I'd be terrified flying in a four-engine plane - the risk of an engine failing is TWICE as great as in a twin!

(and ferry pilot Max Conrad preferred flying a single across the pond.) :ok:

(And you won't get me anyways near a B-52...) :rolleyes:

ChrisVJ

11th Nov 2013, 22:49

With passengers in the back I believe the convenience of service facilities and whether you have to buy room nights should not be the issue. The only issue should be "Which airport is the safest option at this point."

There have been a number of successfully continued flights in the last few years but I am wondering what the inspector would say in the case of a further shutdown and crash when the aircraft has flown past a safe landing point and further, what the flying public would think of the airline.

But then I prefer safety to convenience. Once we do something marginal we get used to it and sooner or later it becomes 'standard practice.' Just personally I think adjusted power take offs for noise reduction and 'saving the engines' are madness and the idea that we should fly an aircraft with three hundred passengers on it five thousand miles with a major systems failure, (and a quarter of your engine power lost is a major failure,) as an alternative to a safe landing that is immediately available is madness too. Just because the aviation community has got used to the idea doesn't make it sensible.

Sooner or later this will go wrong and then we'll have a major reset.

flarepilot

11th Nov 2013, 23:21

chrisvj

yours is really something to think about. it is steady and well thought out...from the perspective of our passengers.

what could have happened?

when a pilot makes a decision, does he do it with the best interest of his:

company

crew

passengers

self?

I would also sort of like to know what happened to the joke about the B52 and why it, and my post saying if it were an F4 it would be funnier , are no longer on this thread.?

and yes, the regulations would allow for this operation.

but just because something is ''legal'' does it make for the best decision?

newt

11th Nov 2013, 23:26

But then I prefer safety to convenience. Once we do something marginal we get used to it and sooner or later it becomes 'standard practice.' Just personally I think adjusted power take offs for noise reduction and 'saving the engines' are madness and the idea that we should fly an aircraft with three hundred passengers on it five thousand miles with a major systems failure, (and a quarter of your engine power lost is a major failure,) as an alternative to a safe landing that is immediately available is madness too. Just because the aviation community has got used to the idea doesn't make it sensible.

What a load of tosh!! You assume there is no risk assessment! The crew would have looked at all the options! They would have reviewed their situation and made contingency plans for the remainder of the flight. Hence their eventual diversion! :ugh:

Normal operations on a well run four engine aeroplane!

deefer dog

11th Nov 2013, 23:29

Another non event that prompts a boat load of uninformed comments from many here who have never qualified to fly anything with more than one or two engines, and probably not even jet ones!

parabellum

12th Nov 2013, 00:17

In the A380, after an engine has failed, does the telemetry for that engine still get transmitted? Limitations on windmilling I heard about, on a different and older design engine, were to do with ancillaries, like pumps and generators etc. that were driven by the engine and relied on the engine oil supply to function properly, might overheat if the oil supply and/or pressure dropped below an acceptable value and led to seizure of the ancillary component and damage to the engine. Functioning telemetry might well be able to monitor this thus removing any set time limit for windmilling?

barit1

12th Nov 2013, 00:41

Speaking from long experience with modern turbines:

Windmilling is a non-issue. Short of oil starvation, you can fly with one shut down until you run the tanks dry, and bearings/seals/pumps will suffer no harm.

And derated and/or reduced-thrust ops are so universally standard that they form the very foundation for the very safe & economical airline industry. Pprune seems to attract a few trolls who have never earned airline stripes, and they profess to have a better plan - but their engines get yanked many times more often than the airlines' engines. Hot rodding is just fine, but don't expect the airline pax to subsidize all that noise!

Capn Bloggs

12th Nov 2013, 00:52

will be to discuss the failure with MAINTROL

Pprune seems to attract a few trolls

Is Maintrol the commander of the trolls?

goldfish85

12th Nov 2013, 01:03

I have some real drivel in this thread. I have to admit I heard the same when BA attempted an engine out transatlasntic flight.

I don't know what UAE's rules are, but taking the FARs (§121.565 ) as exemplary, the rules are
Two engines: Nearest suitable airport in point of time.
More than two engines: Nearest suitable airport unless the pilot determines that it is at least as safe as the nearest suitable airport.
I don't see how in the world one can say attempting to fly toDubai is at least as safe as landing in Nova Scotia or even Europe.. I understand arguments about inconvenience and the cost, etc., but the word convenience doesn't appear in FAR 121.565. By the way, wasn't there any inconvenience by landing short in Kuwait.

(The same arguments apply to BA replacing Nova Scotia, Dubai, and Kuwait with Los Angeles, London, and Manchester.

I know people have done ion one engine (I have) but we're talking about air carriers.

:ugh:

Squawk7777

12th Nov 2013, 01:46

Another non event that prompts a boat load of uninformed comments from many here who have never qualified to fly anything with more than one or two engines, and probably not even jet ones!

Non-event? Uninformed? I guess the Canadian TSB feels the same way! :ugh:

How could the crew (and engineering) have known at the time of failure that there wasn't more to it than a simple engine failure? How do we know that a fuel pump wouldn't leak before we start our trans-Atlantic crossing? Small fuel leak, increasingly becoming bigger could have changed the whole scenario. Pushing one's luck doesn't make it safe. :ouch:

With passengers in the back I believe the convenience of service facilities and whether you have to buy room nights should not be the issue. The only issue should be "Which airport is the safest option at this point."

There have been a number of successfully continued flights in the last few years but I am wondering what the inspector would say in the case of a further shutdown and crash when the aircraft has flown past a safe landing point and further, what the flying public would think of the airline.

But then I prefer safety to convenience. Once we do something marginal we get used to it and sooner or later it becomes 'standard practice.' Just personally I think adjusted power take offs for noise reduction and 'saving the engines' are madness and the idea that we should fly an aircraft with three hundred passengers on it five thousand miles with a major systems failure, (and a quarter of your engine power lost is a major failure,) as an alternative to a safe landing that is immediately available is madness too. Just because the aviation community has got used to the idea doesn't make it sensible.

Sooner or later this will go wrong and then we'll have a major reset.

Well said! Your risk assessment is limited when airborne. You can only rely on your current computed indications which may not prove reliable depending on the failure (see HL-3378 and EK-132).

Squawk7777

12th Nov 2013, 01:58

I see a repeat:

link (http://www.aero-news.net/index.cfm?do=main.textpost&id=1d72e828-0bd8-4c60-b545-7cf088bca0f2)

Sun, Feb 27, 2005
British Airways 747 Crosses Atlantic On Three Engines
Engine Failed On Takeoff, Pilot Chose To Continue, Ran Short Of Fuel But Saved Company Nearly $200,000

On Saturday, February 19, a British Airways flight took off from Los Angeles' LAX airport, destined for Heathrow, with 351 pax and crew aboard. Shortly after takeoff, with the aircraft not more than 100 feet over the ground, controllers notified the pilot that a shower of sparks could be seen coming out of one of the engines. The pilot responded by throttling back, but the engine continued to overheat and the crew decided it had to be shut down.

You would think that the aircraft would immediately make plans to return, including dumping fuel if necessary, and turn back to land at LAX, no? Not this time.

After circling the Pacific for a few minutes while the captain contacted BA's control center, the crew decided to continue the 11-hour, 5,000 mile flight to Heathrow on three engines, rather than turn back and face a minimum five hour delay, at an estimated cost of nearly $200,000. Just three days before, a new EU regulation had come into force that would have required British Airways to compensate the passengers for long delays or cancellations.

The British Air Line Pilots' Association wasted no time in reacting to the incident with a statement warning the industry that the new regulation could have the result of pressuring pilots to take more risks for the sake of avoiding expensive compensation rules. Had the BA flight been delayed more than five hours, the airline would have been forced to compensate the passengers the full cost of their tickets as well as flying them to their destination for free and providing them with hotel accommodations for overnight delays.

The airline had initially stated that the engine failure occurred an hour into the flight, but the facts soon changed when it was determined the engine problem had happened only seconds into the flight. To make matters worse, the crew knew that the aircraft would burn more fuel because it would be unable to climb to FL360, its assigned altitude. Instead, it was forced stay down at FL290 with extra rudder drag due to the differential thrust created by the engine shut down. As the aircraft made its way to Heathrow over the Atlantic, the crew realized they wouldn't have enough fuel and requested an emergency landing at Manchester airport, where the London Times reports the aircraft was met by four fire engines and more than two dozen fire fighters.

BA denies that financial considerations played a part in the decision to continue the flight. Captain Doug Brown, BA's 747 Senior Captain, said the only issue was “what was best for passengers.”

“The plane is as safe on three engines as on four and it can fly on two. It was really a customer service issue, not a safety issue. The options would have been limited for passengers [if the plane had returned to Los Angeles],” Brown told the London times. He also pointed out that the captain of the 747 would have had to dump tens of thousands of gallons of Jet-A over waters just off the coast of California, which would have raised serious environmental concerns. “The authorities would have had words to say about that,” said Brown.

However, David Learmount, safety editor of Flight International, questioned the decision to continue the flight all the way to Great Britain. “It was a very odd decision to continue to London," said Learmount. "Even if the pilot didn’t want to dump so much fuel, he could have diverted to Chicago. You are not as safe on three engines as you are on four and I suspect that, given the choice, most passengers would have opted to return to LA.”:ugh:

emratty

12th Nov 2013, 02:20

As a skipper on the 380 I feel well enough qualified to comment on this. The simple fact is the A380 on 3 engines is as safe as any modern twin. This crew made the correct decision to continue the flight given the amount of information they had. For those that worry about fuel contamination and further failure they are using an outdated argument. The 380 has telemetry on a level greater than a formula 1 car and every plane is monitored not just by Emirates but Airbus and Engine Alliance, the fuel pump problem would in all probability be known about before the crew got any warning.
I don't expect people who have not flown this aircraft to fully understand its capabilities and it's huge redundancy in every department ( including engines!!) but the comments from the few people on here about this being unsafe are just ludicrous and show a complete lack of understanding of 4 engined operations.

flarepilot

12th Nov 2013, 03:00

I wonder what captain smith spoke about when the capabilities of the TITANIC were discussed.

Did he speak of modern technology, of redundancy, of making a fast crossing?

technology vs judgment vs money, vs inconvenience

rottenray

12th Nov 2013, 03:30

How could the crew (and engineering) have known at the time of failure that there wasn't more to it than a simple engine failure? ACARS.

Most pilots today have absolutely NO incentive to continue a flight which could reflect badly on his or her record. Most airlines have absolutely NO incentive to endanger their passengers.

The A380 "knows" more about its engines, etc., through sensors and monitors than you probably knew about your children attending school.

It's nice to see the uproar, but this is really a non-issue - except for bored aficionados who desperately need something to talk about, something which lets them show how much they know about the industry and how much lore they can pull up.

Hi_Tech

12th Nov 2013, 03:48

Most of the blogs appears to be from people stuck on 2 engine mentality. Yes on a 2 engined, you look for the nearest safe runway to put down the bird. There will be hardly any other considerations.
But on a four engined plane you have lost only 25% when one engine goes to sleep. As a technical person I have dealt with similar situations several times. I remember when my company flew an aircraft for over 5 hours on 3 engines, without a hitch. That was a B747 classic. I can quote several such instances on B747 with various airlines.
Those days none of the modern instrumentation or data down link existed. You go by what you experienced in the cockpit and what you saw on your instruments before and during the event. The decision is made by the pilots to continue or not. Rarely they contacted Maintrol for advice for those critical decisions, because we were blind on the ground with out the data dump those days.

But now things are different, fortunately. Moment the engine shuts down, there is a huge data dump to the maintrol and to the engine manufacturer, RR or EA or GE. The events that follow are as below.
If it is a complex issue, a conference call to the engine manufacturer is made to analyse the event. The concurrence on what has gone wrong is very swift. By that time the Captain will be on a SAT call to give us a run down as to what he saw or experienced. The technical team then advise the crew what their conclusion is, and whether to continue or turn around. The captain normally concur, though their decision is final and rarely questioned later.
Never a thought goes in our mind about the $ involved for diversion etc, during the decision process. It is always about safety first. The huge data that is received these days helps to take a safe and very correct decision. So please do not speculate that decisions are based on how many thousand $ saved etc. That is far from reality. If some one quotes a figure of the thousands saved, it is just an after thought, or a good press story.

Of course if the same engine failure on this A380 had taken place with a bang and fire warning etc, I am sure crew would have taken a U turn immediately, without even bothering to call any body. The Kuwait stop was probably as they consumed too much fuel at low altitude. Otherwise the flight would have made it to the destination and few would have known about it.

wiggy

12th Nov 2013, 05:17

Having done quad in the past a little "there I was" story". I just once had to shut an engine down in the cruise (due to low oil pressure - the engine was running fine). We were over a part of the world where whilst we had alternates with nice long runways they would have been a nightmare from both a political and a logistical /passenger handling POV. Head office and the engine manufacturers were on the case before we'd finished drifting down, thanks to the wonders of datalink and satcom, all our onward alternates were pretty much CAVOk so after due consideration we plodded on a scant three engines for several hours to destination. Safety report filed, never made the papers, didn't even make the company's horror comic :rolleyes:.

I suspect if we'd dumped fuel and landed on the nearest suitable piece of concrete, which seems to have been the knee jerk solution some are suggesting it would have taken days to get the passengers out and weeks to move the aircraft.....but I guess we would have had plenty of time to debate the merits of continuing. So FWIW so would I do the same again in the same circumstances if I was on a quad - yes, absolutely.

Now I fly a twin as Hi_Tech has said the thinking is somewhat different, but we're discussing engine failure on a quad, right?.........

haughtney1

12th Nov 2013, 05:56

I don't know what UAE's rules are, but taking the FARs (§121.565 ) as exemplary, the rules are
Two engines: Nearest suitable airport in point of time.
More than two engines: Nearest suitable airport unless the pilot determines that it is at least as safe as the nearest suitable airport.
I don't see how in the world one can say attempting to fly toDubai is at least as safe as landing in Nova Scotia or even Europe.. I understand arguments about inconvenience and the cost, etc., but the word convenience doesn't appear in FAR 121.565. By the way, wasn't there any inconvenience by landing short in Kuwait.

Goldfish, you can quote the FAR's until you are blue in the face, the fact is the FAR for aircraft with 3 engines or more uses the words "makes a reasonable decision" along with the attendant decision criteria.
Taking a 380 into Nova Scotia (yes I've been there) for anything other than an emergency is plain stupidity on the basis of half a hundred different factors, moreover given the nature of the engine issue, I'm fairly certain that the crew would have made a no nonsense "reasonable decision" (despite all the rumblings about EK as an employer, I am yet to meet anyone here that values their job over their life)

Jonty

12th Nov 2013, 06:57

To be fair, the Airbus will tell you if it needs to land.

Bergerie1

12th Nov 2013, 08:03

Thank you emratty and Hi_Tech for a much needed dose of knowledge and good common sense. I spent my whole career flying long-haul 4 engine aircraft and totally agree with you.

I remember, on a 747 Classic shutting down an engine because of reducing oil pressure when over Nova Scotia. It was a simple precautionary shut down. We continued to London where the weather was good rather than landing in Canada in winter. In those days there were no data links and it didn't require any discussion with HQ, the decision was obvious and totally safe.

FullWings

12th Nov 2013, 08:26

Oh no, here we go again!

Maybe there should be some sort of "sticky" FAQ on "flight with one engine less than normal" at the top of R&N, which people could review before posting on threads like this.

In the current absence of such a document, how about a few facts:

* Aircraft like the A380 are designed and certified to fly for an unlimited period, one engine inoperative (OEI).

* Following an engine failure, a diagnosis and exhaustive review of the options available will take place. This will normally include input from pilots, engineering, the aircraft & engine manufacturers and management.

* If the captain makes a decision to continue, possibly to destination, the effects of a further failure will have been explored and prepared for.

* Because of its size and weight, airfields that are suitable for an A380 to operate in and out of are rather thin on the ground. There are plenty that could be used in a time-critical scenario (smoke/fire, etc.) but you'd likely be stuck on the runway and/or unable to park, taxi or anything else.

* Despite arguments to the contrary, convenience and cost do come into consideration. The passengers have paid to go from A to B, not by way of a day or two in F. If you can achieve this without a significant increase in risk, which is what the aircraft is designed to do, then it is a proper option.

* The professionals who operate these types of aeroplane are fully aware of the nuances of flight continuation and regularly practice losing one or more power plants and the decision making process involved afterwards. They also wish to survive the experience.

blind pew

12th Nov 2013, 08:29

With all of these safety systems, telementry and full time monitoring in place please explain how Quantas nearly lost a 380?
Submissions on a post card to Old [email protected] a so called professional.

Ancient Observer

12th Nov 2013, 08:34

Oh, FFS.
The only reason the BA flight made the media was the FAA saw a chance to promote USA based airlines.
Parts of the FAA are required to promote USA Aviation.
Other parts deal with safety.

The safety part was extremely embarrassed by the political part going public about this issue.

pprune readers would not even know about that BA flight if the politicians in the FAA had not heard of the story.

As wiggy says, with a 4 engine plane, it is perfectly OK to run with 3 of them.
End of story.

Sober Lark

12th Nov 2013, 08:59

All the information available lead them to believe they would make it to Dubai but they only got as far as Kuwait. How do you interpret that margin of error?

FullWings

12th Nov 2013, 09:35

All that shows is that there was an active decision making process. Every day, all around the world, there are aeroplanes that set off to a particular destination but end up somewhere else, be it for weather, delays, technical or passenger issues.

Maybe they couldn't get optimum levels, the wind forecasts were out or they had to re-route across the Atlantic. Or maybe DXB wasn't reachable initially but they thought it might be if they could make fuel en-route. I'd guess that as they approached KWI, the fuel predictions for DXB were below what they had decided as a cutoff point, so they went into KWI instead. No drama, nothing to see...

Jet II

12th Nov 2013, 12:11

All the information available lead them to believe they would make it to Dubai but they only got as far as Kuwait. How do you interpret that margin of error?

They knew from the outset that they wouldn't get to Dubai. Kuwait was chosen as it was close enough to position a relief 380 there at the same time as they would arrive.

Momoe

12th Nov 2013, 15:37

In reply to Blind Pew

Appropriate moniker, telemetry will only advise what is happening in real time (Or in the Qantas accident as fast as it gets to the head of the queue)

Do you really think that if the telemetry indicated a potential uncontained engine failure the crew (or company) would have carried on?

I fail to see any value in comparing these flights, controlled engiine shutdown vs uncontained engine failure with substantial damage to aircraft - Where's the relevance to this thread?

Ian W

12th Nov 2013, 16:01

ACARS.

Most pilots today have absolutely NO incentive to continue a flight which could reflect badly on his or her record. Most airlines have absolutely NO incentive to endanger their passengers.

The A380 "knows" more about its engines, etc., through sensors and monitors than you probably knew about your children attending school.

It's nice to see the uproar, but this is really a non-issue - except for bored aficionados who desperately need something to talk about, something which lets them show how much they know about the industry and how much lore they can pull up.

I agree on the telemetry and that the engine manufacturers can often run remote diagnostics on the aircraft.

However, the 'all knowning' A-380 systems in this case did not say 'Excuse me captain but the duplicated for resilience fuel pumps in number 4 are going to fail in 30 minutes" Nor did they telemeter a warning to the IAE. The fuel pumps failed both of them- and the crew got the message that the engine had failed at the same time as IAE engineers.

Now when two separate, redundant, items fail at the same time that should raise flags that all is not good. There could be a common mode failure - perhaps line engineer 'Murphy' on DI's carefully did something which screwed each of the fuel pumps (or associated equipment) on number 4, and he had happily repeated the exercise on the other three engines.

While I agree that 4 engine aircraft are specifically designed to allow safe three engine operations, this may be more to cope with events such as birdstrike or a single point of failure such as an oil leak. Concurrent failures of redundant systems as in this case, are different animals and should be treated with a lot more caution.

DaveReidUK

12th Nov 2013, 16:11

The simple fact is the A380 on 3 engines is as safe as any modern twin. That may well be true of the A380 (though it's not immediately obvious why), but as a generalisation re twins vs 4-engined aircraft it isn't.

5 APUs captain

12th Nov 2013, 16:20

Nothing to discuss at all!
ANY 4-eng aircraft MAY continue to the destination!!!
Good job, well done!

heavy.airbourne

13th Nov 2013, 03:08

:= May I suggest to exclude A340-200s and -300s ...?

JohnMcGhie

13th Nov 2013, 04:22

OK, obviously the engine could not gravity-feed.

And I suppose the reason is "because they didn't design it that way".

Excuse my ignorance: I thought all wet-wing aircraft with under-slung engines could gravity-feed fuel to the engines if you kept the tank above the engine full.

So my question is "Why did they design the A-380 so that it can't gravity-feed?"

Or are you saying that the failure of one of the pumps blocked the fuel line to the No. 4 engine?

Curious minds...

Leg

13th Nov 2013, 06:40

Deefer Dog, what a very rude chap you are, what type of power plant one has hanging off ones wing is not an indication of ones ability or knowledge.

There are many talented individuals who have never operated jet equipment, they are not lesser people because of that, you sir are a brigand.

jefferson-airplane said...

1. A significant amount of fuel would have to be jettisoned
2. Hotel accommodation for 20+ crew and 450-500 passengers
3. Nothing less than a 24 -36 hour delay before replacement components could be sourced, shipped and installed

Option 2 is irrelevant in this instance.

And in absolute safely.

Really? I absolutely doubt that... :ugh:

Clandestino

13th Nov 2013, 07:33

what type of power plant one has hanging off ones wing is not an indication of ones ability or knowledge. True, but posts around here sometimes correlate with knowledge and it is only natural to assume folks who have no idea about four engine long range operations have never participated in them - alternative explanation would be just too scary. I'll never understand why people feel the need to parade their opinionated ignorance on the site that has "Professional" in its title. If you want to impress someone with your "knowledge" of quad operations or whatever, why don't you go with your comments to some general media outlet? Larger public and smaller chance of calling your bluff there.

RandomPerson8008

13th Nov 2013, 08:08

I don't know why people would be upset with the crew on these sorts of decisions anyway.

It's long standing policy for operators of four engine jets to continue after a single engine failure unless there is a good reason not to. The decisions are made in conjunction with dispatch, maintenance, and various other entities within the hierarchy of the operating airline. If the captain were to unilaterally make the decision to divert simply out of an abundance of caution, it would be viewed as an overreaction and disciplinary action would probably be considered by his or her superiors.

The manufacturer approved checklists for such scenarios do not say "divert to the nearest suitable airport". They do however, say to do so for engine severe damage or separation.

If you want to be upset with someone over 4 engine jets covering long distances on 3 engines, consider taking it up with the manufacturers of these aircraft and the airlines that operate them. The crews are simply doing their best to adhere to the procedural framework established by these entities.

Leg

13th Nov 2013, 08:25

First rule in aviation, never assume!

Of course this crew looked at all options and deemed
it safe and prudent to continue, what irks is the rationale
of some with 4 jet (not 'quad'... please)
experience is rather blinkered, and quite frankly pompous!
Some need to read up on risk management methinks.

Safe to continue, but 'absolutely safe'? , as I said, doubt it.

Jwscud

13th Nov 2013, 08:28

If the captain were to unilaterally make the decision to divert simply out of an abundance of caution, it would be viewed as an overreaction and disciplinary action would probably be considered by his or her superiors

I find that suggestion deeply troubling.

pontifex

13th Nov 2013, 09:32

This is called the Professional Pilots Rumour Network. I honestly believe that some sort of filter should be put in place to try and ensure that that is what it returns to become just that!

Best foot forward

13th Nov 2013, 10:16

Don't know if this has been posted but it is the report on the BA flight from LA and explains the occurrence quite well.

http://www.aaib.gov.uk/cms_resources.cfm?file=/Boeing%20747-436,%20G-BNLG%2006-06.pdf.

Just a guess but gravity feeding about 3000kg an hour would be impossible with the size of the fuel lines on any acft.

The following paragraph is taken from this document.

http://www.united-virtual.com/uploads/Boeing_Training_2.pdf

So the use of APU in the 747 apart from gate power is limited to an APU-PACK departure. The reason is that
the engines on the 747 are deemed to have a very strong windmill, so even if "dead" they are able to turn freely
to generate electricity and of course there are 4 of them, so losing them all is very unlikely. So it was decided on
the 747 to allow the engines to windmill for electricity, or to have one of the running engines support power.

Swedish Steve

13th Nov 2013, 10:36

. The reason is that
the engines on the 747 are deemed to have a very strong windmill, so even if "dead" they are able to turn freely
to generate electricity and of course there are 4 of them, so losing them all is very unlikely. So it was decided on
the 747 to allow the engines to windmill for electricity, or to have one of the running engines support power.
What is this, model aircraft design? Who in United is involved?
That site is full of half truths. When an engine is windmilling, it will produce hydraulic pressure, and power the dedicated generator for the FADEC. It will not produce electricity from the IDG.
I hope you are not a real pilot reading this!

Good Business Sense

13th Nov 2013, 11:04

.... seems a lot of people should not get out of bed in the morning - they certainly shouldn't go into the bathroom, statistically one of the most dangerous places on earth. The drive to the airport or the crew bus to the hotel aren't much better :)

I've been unlucky enough to have had quite a few (into double figures) engine failures on 2, 3 and 4 engine jet aircraft - the failures ranged from nasty to benign :eek:

As always after the noises were cancelled and the checklists run a cup of tea was ordered and the situation was considered carefully. Years of experience, technical knowledge, airmanship etc were then employed by all on the crew to decide on the way forward - it seemed to work out well on all occasions and yes, I did divert on one of them but then 330 people on one engine does call for a bit more prudence. Professionals at work or at least I like to think so.

Not once did the company exert any pressure, nor did they call me up afterwards for an "explanation" :D

A few years ago the monitoring of the aircraft, particularly the engines, by computers through satcom was an incredible leap forward as an aid to dealing with this type of situation. Call the maintenance dept and they can give you an incredible amount of detail on what is going on - oh, and handily ops would send you an updated engine out CFP ... mind you, the old rules of thumb still seem to work.

It might irk a few here but, I've got to say dealing with the failure of an engine is very much like dealing with the failure of any component on the aircraft.

If what everyone wants is the "LAND IMMEDIATELY/ASAP/NEAREST" instruction at the end of the checklist so that you don't have to think, exercise any airmanship or demonstrate any professionalism then two things will happen - firstly, you will actually cause yourself much more grief on most occasions (good luck in ADAK) and secondly, we'll see drones before you know it :)

I just think that if you want aviation to be so black and white you might be in the wrong business (I blame the digital age - particularly when the PNF is calling +2, +3 down the approach :) :ugh:)

... can't think of any flights in the recent past that crashed because they continued a flight after shutting down a jet engine (where the shut down engine caused the crash) - is it really an issue or, over the years, have we actually dealt with the scenarios/failures professionally as we should have done? Has anything changed ?

:ok:

DaveReidUK

13th Nov 2013, 11:21

I hope you are not a real pilot reading this!Er, the author of the quote (and owner of the United-Virtual.com domain) is a Canadian eye surgeon and flight sim enthusiast - who is probably as surprised as you are that his sim rules are being quoted, unquestioningly, on a professional aviation forum. :O

flarepilot

13th Nov 2013, 12:19

lucky for this airbus 380 that the windshield didn't develop a crack.

oh, and regarding ''gravity'' feed...I can't think of a jet engine that doesn't require its own fuel pump to properly feed itself. that all important engine driven pump is pretty darn important. ''boost pumps'' ensure stability of fuel flow throughout the operational altitudes and attitudes, although some planes at some altitudes can lose all boost pumps and ''suction'' feed via engine pump....without that engine pump ouch

lomapaseo

13th Nov 2013, 12:43

Are we talking about an engine driven fuel pump that produces the pressure necessary to feed spray nozzles in the burner ?

Or a pump that moves fuel between aircraft systems ?

flarepilot

13th Nov 2013, 12:44

the former and not the later. iompaseo

ex-gill

13th Nov 2013, 13:19

I am always confident that the flight deck crew will make the correct decision. After all there are enough of them, they are quite intelligent (at least as flying is concerned) and they are in no way over burdened by hard work. No flaming required, just saying .....

FlexibleResponse

13th Nov 2013, 13:39

These days, most two engined aircraft take off and complete the flight on only two engines.

Once a four engine aircraft is safely airborne, it no longer needs all four engines to continue the flight to any destination with more safety than any two engine aircraft that hasn't yet taken off...

See the Air Regulations of any half respectable Authority concerning such operations...

gcal

13th Nov 2013, 13:44

These days (and for a few decades) I'm sure you are quite right.
However I remember the Lockheed Consternation and wouldn't have put it to the test - too often :oh:

Self Loading Freight

13th Nov 2013, 13:45

I'd have no problem being on that flight. If ever there was a contingency likely to have been previously looked at every which way to Thursday, it's losing an engine; I very much doubt there were many decisions to make that hadn't been pre-planned, reviewed and signed off by everyone involved long before this incident.

What is interesting, as mentioned up-thread, is that both pumps failed. As the initial report said that the aircraft was signed off after they'd been replaced, the failure mode seems likely to be due to the pumps themselves rather than an external factor, excepting perhaps bad maintenance.

Does anyone know the details of the pump system on this engine, and whether any common factor could lead to dual pump failure?

DaveReidUK

13th Nov 2013, 15:08

Once a four engine aircraft is safely airborne, it no longer needs all four engines to continue the flight to any destination with more safety than any two engine aircraft that hasn't yet taken off...Are you implying that once the twin is airborne, that proposition no longer applies?

If not, could you explain the significance of your proviso that it "hasn't yet taken off"?

If there exists a definition of (and a way of measuring) "safety" that renders a 4-engined aircraft flying on 3 "safer" than a twin flying on both, it's not immediately obvious what that definition/metric would be.

Megaton

13th Nov 2013, 15:11

Once a four engine aircraft is safely airborne, it no longer needs all four engines to continue the flight to any destination with more safety than any two engine aircraft that hasn't yet taken off...

Strictly speaking, some aircraft don't even need the fourth engine to get airborne. I've operated a three-engine ferry on a four-engined aircraft without any drama. No passengers or crew of course. Also, four engine performance caters for an engine failure after V1 and before rotate so, to be utterly pedantic, a 747 doesn't even need the fourth engine to get airborne; the fourth engine merely needs to get the aircraft to v1!

BOAC

13th Nov 2013, 15:26

If there exists a definition of (and a way of measuring) "safety" that renders a 4-engined aircraft flying on 3 "safer" than a twin flying on both, it's not immediately obvious what that definition/metric would be. - I just cannot resist pointing out that the subsequent engine failure would result in only a 33% loss of available power or a 25% loss of full power? Thus after 2 failures, 'Mr 4' is in the same boat (no pun intended) as 'Mr 2' after 1.

DaveReidUK

13th Nov 2013, 15:57

Thus after 2 failures, 'Mr 4' is in the same boat (no pun intended) as 'Mr 2' after 1.Exactly my point.

So, given that the starting point for the comparison is an all-engines-operating twin vs a 4-engined aircraft with one failed, the argument seems to be that the likelihood of an engine failure on the twin is higher than the likelihood of one of the 3 remaining engines failing on the quad.

That's counter-intuitive.

RAT 5

13th Nov 2013, 16:14

Paddy & Mick were en-route to XYZ in a 4 engined a/c. The captain came on the rail and apologised for "an engine failure, but no problem they would continue and arrive 1 hour late. Please enjoy the refreshments." Paddy & Mick thought this a great idea to have 1 hour more Guinness time. Later the captain came on again to inform them of a "2nd engine failure, but no problem, they would continue and arrive 2 hours late. Please enjoy the refreshments." Paddy and Mick could now look forward to 2 hours of extra Guinness time. A short while later the captain came on again with grave news. "a 3rd engine failure, but no problem, they would continue and arrive 4 hours late. Enjoy the refreshments." Paddy & Mick thought enough Guinness was enough and Paddy made the very astute observation that "good Lord Mick, I hope the other engine doesn't stop otherwise we'll be up here for ever."

I've flown ETOPS on 2 donks and would be far more wary of diverting 3 hours on 1 engine to 'nearest suitable' than continuing en-route on 3 .

bubbers44

13th Nov 2013, 16:43

One of our B727's lost an engine over El Paso and our op specs said we could continue with two engines, not land at nearest suitable airport as our twin jets. They landed at LAX and found one engine missing. It was found on someones property near El Paso. I was asked to fly our Jetstar on three engines from BUR to LAX for maintenance and refused because BUR has fairly short runways and terrain and it was just to save higher maintenance cost of having it fixed there.

It is the captains call how to handle it so let him decide. If it is legal decide if it is safe. A lot of things are legal but not necessarily as safe as erroring on the side of caution.

Ian W

13th Nov 2013, 17:01

Exactly my point.

So, given that the starting point for the comparison is an all-engines-operating twin vs a 4-engined aircraft with one failed, the argument seems to be that the likelihood of an engine failure on the twin is higher than the likelihood of one of the 3 remaining engines failing on the quad.

That's counter-intuitive.

And also wrong

Given that all engines have the same probability of failure and are independent entities (so one failure does not cause another) an aircraft with 3 engines has more likelihood of an engine failure than an aircraft with two engines. If you like the aircraft has three tickets in the failure lottery compared with two tickets in the failure lottery.

The EFFECT of the failure may be more profound on the twin engined aircraft. Though even there some 4 jets reduced to two could be in a worse position than a twin reduced to one. An A340 with both engines out on one wing would be a little less capable than an A330 with one engine failed.

DaveReidUK

13th Nov 2013, 17:08

Thanks for the confirmation, Ian, I was beginning to doubt my sanity. :O

Dengue_Dude

13th Nov 2013, 17:48

I flew around for years on 3 engines - a complete non -event - a bit like this thread.

Mainly DC10s, but with a smattering of TriStars of various flavours.

bubbers44

13th Nov 2013, 19:12

Super VC-10

13th Nov 2013, 19:24

Bubbers -

https://en.wikipedia.org/wiki/Eastern_Air_Lines_Flight_855

ShyTorque

13th Nov 2013, 19:44

Strictly speaking, some aircraft don't even need the fourth engine to get airborne. I've operated a three-engine ferry on a four-engined aircraft without any drama.

Many years ago I took off single engine in a twin, from an oiled sand island strip and ferried it across the sea. All legal and above board. I'm still here.

Georgeablelovehowindia

13th Nov 2013, 20:07

I flew around for years on 3 engines - a complete non -event - a bit like this thread.

Mainly DC10s, but with a smattering of TriStars of various flavours.

Good grief!! You've brought back memories of those horrendous Two Engines Inoperative charts (DC-10). You went into them at the pre-flight planning stage to determine if you might have to limit zero fuel mass, so that you didn't have to jettison so much fuel to avoid going splash, leaving not enough to reach dry land.

Fortunately, this proved to be irrelevant on trans-Atlantic routes so for us it was only ever a base-check questionnaire teaser.

Shows how much thought does go into the ramifications of continued flight with engines inoperative, though.

Yes, and you did read me right: Two engines inoperative.

400drvr

13th Nov 2013, 20:24

I think I'll take my crew rest now. Wake me 90 minutes out.

;-)

flarepilot

13th Nov 2013, 21:35

Decision Making Process:

lose engine...worry for 12 hours get close to home.

or

lose engine, dump fuel return to land at airport I just took off from, where the weather is about the same as when I took off, go to hotel, go see a play and get a nice dinner.

Attempt trip next day.

there are many considerations in any situation

bubbers44

13th Nov 2013, 22:03

23,000 hrs with no real engine failures just a precautionary shut down to avoid hydraulic contamination makes me feel very fortunate. I still treat each flight the same not expecting my luck to last. Flying one, two, three and four engine aircraft I have never lost an engine. I did once when I was showing my cousin how you could take a J3 Cub to altitude and stop the prop and get it windmilling again by diving it but I was young and stupid so had to dead stick it back to the airport and prop it on the runway to taxi in so they would rent to me again when I was 19.

One other time in a Jetstar they forgot to put oil in one engine and we had to shut it down. It was of course the number two engine again so lost normal hydraulics. My chief pilot was flying and I said we lost oil pressure on number two engine and he said it is just a indication problem. I said the low oil pressure light is on, we are going to destroy our engine if we don't shut it down. He reached over and shut it down and said don't tell the controllers. We only flew 20 miles but when he landed the only hydraulics we had was electrical pump. He heard it working so turned the switch off. I was a bit irritated by then but as we were approaching a line of AC and needing to turn saw our pressure drop to minimum so showed him the pressure was almost zero so was going to turn the pump back on. Thank God I got an airline job.

Wally Mk2

13th Nov 2013, 23:00

All a very interesting read on ones take of eng failures in 4 eng planes.

Just off topic a little as it's going round in circles anyway it's obvious to me that the biggest & ugliest flying machine in the air 2day the A380 Dugong has 4 engines for one main reason, they needed x amount of thrust to move such a large mass thru the air & they couldn't get it with just 2 (3 would have meant a totally diff airframe design).

4 engines for the A380 was needed there where no other options not 'cause of 'just in case'
With large engines now producing somewhere around 105000lbs of thrust or so we could almost have a very large SE Airliner carrying hundreds of pax but we don't see anything like that on the drawing board for very obvious reasons.
Safety in numbers:)

barit1

14th Nov 2013, 01:19

I've posted before about a DC-10 that lost #1 at 0200 out of KHI, and after a sequence of diversion plans, pressed on up the Persian Gulf and beyond (DXB-KWI-BEY) to finally make a daylight landing at ATH. I believe he set some sort of record. :eek:

White Knight

14th Nov 2013, 04:14

Just off topic a little as it's going round in circles anyway it's obvious to me that the biggest & ugliest flying machine in the air 2day the A380 Dugong has 4 engines for one main reason, they needed x amount of thrust to move such a large mass thru the air & they couldn't get it with just 2 (3 would have meant a totally diff airframe design).

Award of the day for "bleedin' obvious"... The point though is it needs the grunt to get into the air; however once it's up there in the cruise it certainly does NOT need all that grunt. Why, only the other day I was flying one from DXB to Australia and at top of climb I calculated that an engine failure would mean descending to FL170 or thereabouts (gross weight around 540,000kgs) However, two hours later the engine out profile is much rosier... And with all that gas:p

glofish

14th Nov 2013, 04:25

Although I think the incident was handled well and according regulations and procedures, let’s not forget:

4 engines have double the probability of an engine failure than 2 engines.

3 engines still have a higher probability of one failing than a twin.

Engines working on higher cruise thrust have a higher probability of failure again.

A 4-holer flying with only 2 has less performance than a twin on one hole, per design.

A 4-holer is not ETOPS certified, thus when losing the second hole, is in uncharted territory and on a full blown emergency.

That leads me to conclude that if you lose an engine on a 4-holer, you can continue, but you would be best advised to get into a 60min circle of a suitable airport within a reasonable time. This is not regulation, but looking at the situation from the above side, continuing over extended waters or high terrain on 3 holes might be legal and economic, but certainly not the safest solution.

(I remember faintly that on 3-holers we had en exemption for 120min until we had to be within 60min of a suitable airport, that makes some sense)

Super VC-10

14th Nov 2013, 07:22

... what if the An-225 loses an engine?

Good Business Sense

14th Nov 2013, 07:36

Adverse Jaw

14th Nov 2013, 08:01

My only personal experience of prolonged flight with an engine inop was on a DC10 trans-atlantic. We soon noted a very significant increase in oil consumption, due due breakdown of the labyrinth seals for the windmilling engine. However, we soon established the oil loss to be at at a constant and predictable rate and on this basis continued to destination while closely monitoring oil contents.
No sweat, no drama.

DaveReidUK

14th Nov 2013, 08:24

Glofish, your conclusions are not applicable - you're now into another universe with probability stats if you start to look at two engine failures on a four engine aircraft on the same flight.

You probably have a far higher chance of being hit by a meteorite.No argument with the meteorite analogy, but you're missing the point. While Glofish's conclusions might be debatable, his statements on probability are demonstrably correct re 3 engines vs 4 (see also Ian W's earlier post).

Yes, of course the a priori probability of two successive, unrelated engine failures in the same flight is extremely low (in effect it's a very small number multiplied by an almost as small number).

But we're talking instead about the conditional probability of a second failure given that one engine has already failed. Since the probability of something that has already happened is 100%, we are now talking about one small number, not two small numbers multiplied together.

Good introduction to Conditional Probability here:

https://en.wikipedia.org/wiki/Conditional_probability

Good Business Sense

14th Nov 2013, 09:26

Need to read what I wrote;

I was debating his conclusions !

Didn't say he was wrong on those statements (indeed I agreed with them) in the first part of the post re : engine failure on a "four engine aircraft", engine failure on a "three engined aircraft" and engine failure on a "two engined aircraft" (had all three happen)

but, the argument moved on to apply some interesting conclusions to another completely different scenario and the getting inside a 60 minute circle (why 60) from an airport because you're down to three engines !!

Having spent considerable time on one engine after an engine failure on a twin (more than once) and also on three engines after engine failure on a quad (more than once) I know where I'd rather be. Remember, this thread is about continuing with three engines on a four engine aircraft in a world that allows almost unlimited flight on one engine with circa 350 people down the back.

I've asked twice already but I'll try again, have there been problems with continuing on three engines - any examples ? I know someone mentioned a constellation a couple of pages back but.....

glofish

14th Nov 2013, 10:21

GBS

Your last question is a rhetoric one. I could just as much ask stupidly if continuing with only one on a twin was that much of a problem .... examples EY and a Kenian a few years back and nothing happened either.

I was debating the risk present when deciding to legally continue on three with a 4-holer.

1. I did not read or hear anyone considering the increased risk of failure on the remaining engines due to higher rpm and egt. Why would we derate on T/O if not to increase lifetime and cruising for 12 hours on higher rpm and egt certainly reduces lifetime and increases risk of something turning sour.
2. i pointed at the fact that when you lose the second engine on a 4-holer you are in a less comfortable situation than with a twin losing its first, simply because the latter's power ratio is better on one and its systems are more specifically designed to handle such a situation (ETOPS).

This puts you on a higher risk situation than on a twin for two reasons, therefore my conclusion that continuing over extended waters or terrain might not be the best solution. As simple as that.
I think that it is certainly possible to continue, but some 4-hole jockeys seem a little too enthusiastic about this capability. Just some points to maybe consider a little bit closer.

Good Business Sense

14th Nov 2013, 10:46

1. I did not read or hear anyone considering the increased risk of failure on the remaining engines due to higher rpm and egt
2. i pointed at the fact that when you lose the second engine on a 4-holer you are in a less comfortable situation than with a twin losing its first, simply because the latter's power ratio is better on one and its systems are more specifically designed to handle such a situation (ETOPS).

This puts you on a higher risk situation for two reasons than on a twin,

I can assure you power is increased on the remaining engine on the twin.

Having had an engine failure with a depres at the same time on a twin due air system redundancy problems I'll have to disagree with your comments on ETOPS redundancy - won't even get into ETOPS "dispatch" criteria

Give me lots of hydraulic, electric and air systems any day - this is where the argument goes wrong ...... i.e. viewing the failure of the "power" plant in isolation - n.b. the development of the ETOPS statistical debate was made by ignoring engine failures caused by anything that wasn't a "core" engine fault.

Sober Lark

14th Nov 2013, 11:16

Bottom line is they kept diversion and delay compensation costs to a min and arrived at destination only 5 hours late. Apparently the economic engine is much more important than engine #4.

glofish

14th Nov 2013, 11:19

GSD

If you want to compare with a Twin, your choice, but then again a Twin with a failure lands asap!! So comparison falls short.

I am saying that just because a 4-holer has more redundancy and is not legally bound to land, considering what i mentioned above, it is not automatically a good choice to continue over ........ but i realise i am talking against a 4-hole wall.:confused:

DOVES

14th Nov 2013, 11:42

And so they were not affected by flight and duty time limits.

Good Business Sense

14th Nov 2013, 12:06

Glofish,

This puts you on a higher risk situation than on a twin
- I think we'll have to differ on that one. Can't get my head around three is riskier than one ... after you've lost one.

LAND ASAP is almost academic over the Pacific, Poles etc when the nearest usable is 1500+ miles away - 1500+ on one is a long way.... no, if I had the "choice" I'd rather have three.

Like you (I'm guessing) I've got quite a few thousand hours on wide body twins doing ETOPS (which I enjoyed and have no problems with) - but you can't beat starting with four :ok:

Dufo

14th Nov 2013, 12:11

Isn't probability of losing 2 engines the same on quad or twin?
I mean.. probably the engines and plane don't know how many are fitted.

Except that doing that on a twin wins you a headline title, on a quad only a pprune topic.

Good Business Sense

14th Nov 2013, 12:18

Hi Dufo ... unless I'm mistaken .... according to DaveReidUK and his point on Conditional Probability ...... you're right!

DaveReidUK

14th Nov 2013, 12:22

I think we'll have to differ on that one. Can't get my head around three is riskier than one"Risk" is a combination of two factors - the likelihood of something happening, and the seriousness of the consequences if it does.

It's perfectly legitimate to agree to differ on the degree of weighting that you attach to each of these factors.

Clearly you are correct in that the consequences of losing your one remaining engine on a twin are considerably more serious than the consequences of losing a second engine on a 4-engined aircraft.

Equally, Glofish is correct in saying that the likelihood of losing a second engine is higher (albeit still extremely remote) when there are 3 potential candidates than when there is only one.

Good Business Sense

14th Nov 2013, 13:10

DaveReidUK

Been doing risk assessments for years - It's not the definitions, it's the application of logic.... but I now understand where they come from - I could be wrong but I think Glofish may fly a wide body twin on ETOPS so it's a bit rich and quite incredible he makes the comments below ... no cred I'm afraid

Glofish said:
That leads me to conclude that if you lose an engine on a 4-holer, you can continue, but you would be best advised to get into a 60min circle of a suitable airport within a reasonable time. This is not regulation, but looking at the situation from the above side, continuing over extended waters or high terrain on 3 holes might be legal and economic, but certainly not the safest solution.

SeenItAll

14th Nov 2013, 13:51

Let me raise a different issue. The plane eventually had to divert to Kuwait -- presumably because it could not manage the additional 530 miles to Dubai. Unless Baghdad is an acceptable diversion destination for an EK A380, this means that for the roughly 1000 miles prior to reaching Kuwait, this bird had no good diversion airports available. Does anyone think this might represent sketchy decisionmaking?

Sir Richard

14th Nov 2013, 14:32

No............................:ok:

SeenItAll

14th Nov 2013, 14:43

Sir: If I read your short answer correctly, the availability of diversion airports along the flight path plays no role in decisionmaking as to whether to continue a 3 out of 4 flight?

cockney steve

14th Nov 2013, 14:48

They didn't make "an emergency landing due to desperate fuel shortage"

they made a planned landing within the duration of their SAFE fuel reserves......saved their pax a huge amount of delay and inconvenience...saved the operator a fortune and probably gave time for logistics to organise the last 450-mile shuttle "home"
as a mere industry outsider, I can only see positives in this decision.....had they been in a two-engined machine, I would have looked at it somewhat differently.

they weren't...I didn't. :p

Sir Richard

14th Nov 2013, 14:57

I didn't say that...I just wonder about your 1000 miles?

SeenItAll

14th Nov 2013, 15:05

See Great Circle Mapper (http://www.gcmap.com/mapui?P=jfk-kwi-dxb) for a rough flight path. Other than Baghdad, it would seem that the last major airport that you pass prior to reaching Kuwait is Ankara -- over 1000 miles from Kuwait. Unless, of course, northern Syria or Kurdistan meets EK's druthers.

Sir Richard

14th Nov 2013, 15:20

Yes...that limits the diversion distance to a maximum of 500 miles !

Plenty of flights cross The Pacific, Atlantic, Siberia, etc. more than 500 miles from a diversion airfield every day. :8

SeenItAll

14th Nov 2013, 15:49

I agree. But my question is whether the decision to continue a 3 out of 4 aircraft is made oblivious to whether their are suitable diversion airports along the flight path, or whether this decision would be sensitive to this issue.

To me it would seem necessary that this be an important consideration. After all, with ETOPS, diversion fields must be within certain minimum distances/times. Given that a 2 out of 4 will be in a clear emergency, it would seem that if you only have 3 operating, you wouldn't ever want to be too far away from a diversion field.

Sir Richard

14th Nov 2013, 16:28

I think you will find that most pilots consider possible diversion airfields when everything is working normally, and no doubt pay a little more attention when things are less than perfect.

Decisions....decisions....

http://t1.gstatic.com/images?q=tbn:ANd9GcRQ6h2hTOBrZm2pD2spIDtlKzqM1tYyZEHWCGUobcc Kn8vr3_nxWg

JW411

14th Nov 2013, 17:24

I went solo in 1957. From 1962 until I retired in 2006 I never had less than 4 engines to play with (apart from 8 years on the DC-10).

Crossing the Atlantic or the Pacific in an aeroplane with only two engines was something that would have filled me and my colleagues with horror. I never had to do it. (In fact, I never flew a commercial twin so I didn't even have to contemplate the exercise.)

For me, it was quite easy. If you have four engines running, think three.

If you have three engines running, think two.

In most occasions, the loss of one engine on a four engined aircraft was a bit of an annoyance but was seldom anything even remotely resembling an emergency.

Now, with the advance of modern economics, we are into a situation where just about everything that goes across the Pond does so on two engines so it is hardly surprising that the two engine lobby can't understand the thinking of the four engine lobby who are now in the minority.

The loss of one out of four is a bit of an annoyance.

The loss of one out of two IS AN EMERGENCY.

I don't give a toss about all of these wonderful statistics that we are constantly regaled with. It was probably ten years ago when a United Airlines 777 was headed from the Far East to the USA when it lost an engine. It took it over three hours to get to Hilo in Hawaii on the remaining engine.

Are any of you out there really going to tell me that the crew were more than happy with their situation or do you not think that they might just have wished that they had started off with four engines?

As far as I am concerned, those of you you who have become convinced that flying across the oceans of the world is statistically safer on two engines than it is on four engines have been brain-washed and are more than somewhat deluded.

Purely an observation from a retired old fart (who is still alive).

RAT 5

14th Nov 2013, 19:02

I don't get it; some of the thinking. To be fair I've only flown 2 engine ETOPS, so know only the rules appertaining to that. The route is allowed to be within 3 hours engine out = 1 engine from a suitable airfield. On a B737 that is 1200nm: on B767 it was slightly further. Those are of the slower modern a/c. I'm not aware of the 'ETOPS?' rules for an engine out on a 4 engine a/c. If a 2 engine a/c, suitable equipped for ETOPS is allowed to be 1200nm from a suitable airfield, I'm mighty sure a 4 engine a/c can be almost without limits. Thus I suspect that on 3 engines they would then need to be within +/- 1200nm of a suitable airfield to continue. Then if they ended up on 2 engines they would divert to the 'within 1200nm nearest suitable airfield'.
Am I missing something?

RetiredBA/BY

14th Nov 2013, 19:10

Amazing, truly amazing, that some guys on this forum think they know better than the four type rated pilots, including the two captains, on this A380 who were there and knew all the facts, including their company ops. manual and policy. Critics of this operation would do well to read the AAIB report into the BA 747 engine failure ex LAX including the reference to windmilling and seized engines.

Talk of keyboard warriors !!!

(former 4 engine guy but with 2 engine ETOPS time in the LHS, and my 76 or 75 would have been landed at the nearest suitable airport, pronto, after engine failure, but what's the big deal about an A380 on three ? )

RodH

14th Nov 2013, 19:46

UPDATE : Lost engine found.
It was found attached to its pylon on the wing.
Much relief from all. !!!!!!!!!

That silly statement has about as much value and useful information as most of the posts about this minor issue.
There are some posters that are spot on.
The 4 engine drivers particularly the ones involved in the story are the only ones who really understand it all.
It really is not a big deal.
But I guess it gives Pruners something to air their considerable knowledge about.

To quote William Shakespeare " much ado about nothing "

Super VC-10

14th Nov 2013, 21:35

RAT 5 - yes!

AFAIK, ETOPS only applies to twin-engined aircraft.

Good Business Sense

14th Nov 2013, 21:52

RAT 5

Am I missing something?

- yes

So a 737 has to be within 1200 miles on two but a quad, with all of it's extensive systems redundancy, has to be within 1200 miles on three :ugh::ugh::ugh::ugh::ugh::ugh::ugh::ugh::ugh::ugh:

It's definitely a worry that people think its ok to run around on one because its "ETOPS" but down to three engines on a quad is dangerous - weird world - glad I'm retiring.

barking !!

DozyWannabe

14th Nov 2013, 22:32

I went solo in 1957. From 1962 until I retired in 2006 I never had less than 4 engines to play with (apart from 8 years on the DC-10).

First of all, I should make a point of saying that I have a lot of respect for you and your input, so please don't take anything I say as personal - I'm just trying a bit of Devil's Advocaat*. ;)

To the best of my knowledge in 1962, there was only one four-holer capable of flying indefinitely on one donk. That was the VC-10, and it wasn't common knowledge that it could even back then! :

As an instructor in the RAF VC10 sim we had to similate the procedure for crew activity prior to ditching.
To save time we wrote a programme which meant the crew would leave Brize for Gander/Goose Bay (I forget). After many faults, during start and T.O which we would tick-off the training sheet, we would re-position the crew half-way across the Atlantic close to a weather ship. The briefing was we would cause numerous engine failures where they would apply the appropriate drills, so we could tick them as complete, then we would leave the crew with only one engine and thus they would carry out the flight side of a ditching drill.
On one occasion this crew were descending on one engine at full power and the Air Eng was dumping fuel as per....when the Capt. said "Stop dumping!".
The VC10 had levelled out at full power! A quick check of the fuel indicated they could still fly and they then established they could make it to the coast of Ireland with the prevailing wind.
As instructors we were flummoxed and, as there was another training session later, we needed get this one finished so we reversed the tailwind :E
However, after establishing that the computer and the condition were accurate we reviewed our training to include the possibility of flying on one engine to a better location to land or ditch.
Amazing Aircraft.

Crossing the Atlantic or the Pacific in an aeroplane with only two engines was something that would have filled me and my colleagues with horror.

Are we talking about your colleagues of the 1962 vintage? Not to be facetious, but I'd imagine that from at least the mid-1980s onwards many of your colleagues would have been doing it day in and day out.

As others have alluded to, the advent of stupendously powerful high-bypass donks meant that there was enough power in one of them to keep most airliners flying indefinitely on one.

For me, it was quite easy. If you have four engines running, think three.

If you have three engines running, think two.

Sage advice, and I won't argue with it. However, there's a difference between mentally preparing for the worst and the likelihood of the worst happening.

...it is hardly surprising that the two engine lobby can't understand the thinking of the four engine lobby who are now in the minority.

This is the bit I don't understand. I doubt very much that there exists such a thing as a "four-engine" and "two-engine" lobby. No doubt there are cogent arguments supporting both positions, but I believe that the arguments are based on different criteria than they were, say, thirty years ago.

The loss of one out of four is a bit of an annoyance.

The loss of one out of two IS AN EMERGENCY.

Which is why ETOPS regs are as strict as they are, no?

It was probably ten years ago when a United Airlines 777 was headed from the Far East to the USA when it lost an engine.
...
Are any of you out there really going to tell me that the crew were more than happy with their situation or do you not think that they might just have wished that they had started off with four engines?

It's a bit more complicated than that though, is it not? Given the steady and proven reliability improvements over time, would a crew prefer two PW4000/RB211-500series donks over four JT-9/RR Conways?

As far as I am concerned, those of you you who have become convinced that flying across the oceans of the world is statistically safer on two engines than it is on four engines have been brain-washed and are more than somewhat deluded.

I don't think anyone is convinced that two engines are safer than four, I think it's more to do with a gradual acceptance over time that modern jet engine reliability has shifted the boundaries of the argument. To the best of my knowledge there have been no long-haul incidents involving multiple engine failure as a result of the engines themselves over the last thirty years. Fuel starvation, volcanic dust and maintenance foul-ups, yes (including types with three and four engines) - but none as a result of design-inherent engine failure or reliability problems.

* - Advocate means lawyers - I prefer booze. :ok:

tdracer

14th Nov 2013, 22:37

AFAIK, ETOPS only applies to twin-engined aircraft.

Per a new "Appendix K" to the FAA regulations, effective no later than Jan 1 2015, all new production Part 25 passenger aircraft will be subject to "ETOPS", regardless of the number of engines (never mind that it makes the ETOPS acronym meaningless). In something that I'm sure warms the hearts of you Freight drivers, the rules won't apply to Freighter aircraft with more than 2 engines :confused:

I haven't paid much attention to the new 3 engine ETOPS rules, but the 4 engine ETOPS rules have much more to do with how the other aircraft systems perform during an extended diversion (and the diversion need not be for an engine failure, although that is one of the scenarios that needs to be evaluated).

In-flight shutdown rate is not specified for 4 engine ETOPS.

Boeing is currently in the process of obtaining ETOPS for the 747-8i.

Ian W

14th Nov 2013, 23:11

Glofish, your conclusions are not applicable - you're now into another universe with probability stats if you start to look at two engine failures on a four engine aircraft on the same flight.

You probably have a far higher chance of being hit by a meteorite.:)

As an industry we generally don't do, if, if, if and if and that's what is being done in this thread - there is no evidence that there is a problem here nor that engine out flight has been dealt with other than with successful outcomes.

The statistical probability calculations argue that we've more chance of an engine failure in a 3 or 4 engine aircraft etc - well, that's good, the 747 gets "safer" after it's engine failure. :)

Don't forget that the engine failure stats/data on which ETOPS was founded did not include many failures such as the engine stopping due to a gearbox malfunction etc - the engine had stopped and it was not possible to start it again but as it wasn't a "core engine" problem it didn't count :ugh:

PS there are regs to be complied with if you lose another engine including drift down on two ..... at high weights on two engines most aircraft like the 747, A340 etc need a drift down altitude of circa 10-15,000 feet - there is still a safety net.

There are definitely times when mathematicians need to be re-educated in the real world. Just up-thread we had a brief exchange about an L1011 losing all three engines https://en.wikipedia.org/wiki/Eastern_Air_Lines_Flight_855 .

You see if there are times when Murphy walks around doing the before flights carefully breaking each engine (*) the fault tree can get very short and simple. This is the probability of a human failure which unfortunately can be far higher than people allow for. I won't bore you with anecdotes but there are lots. So yes - if your engines are all perfectly serviced and there are no outside influences the reliability is such that the summed probability of multiple failures is vanishingly small - but common mode failures are not affected by the number of engines slushy fuel, wrong fuel or oil or fuel replenishment etc etc can lead to all of your engines going embarrassingly quiet all for the same reason - often at close to the same time.

That is why when a supposedly redundant (dualed) items both fail you are in different territory and simplistic probability no longer applies. Such a common failure means that there is the potential for an external input that was common to all engines. That's when people earn their pennies making the go/no-go decisions and the crew of course have their own 'flesh in the game' - these decisions should be soundly based.

Fault tolerance, resilience and redundancy is an interesting field

( * Muphy's Law - "If there is a way of doing something wrong - someone somewhere will do it that way."

Not to be confused with

'Sod's Law:- "If anything can go wrong - it will." )

RatherBeFlying

14th Nov 2013, 23:24

Back in the days of recips and those lovely turbo-compounds, loss of a donk before PNR would generally get a turn around.

Pan Am ditched a 377 (aka. Boeing Trimotor) next to a ship on station. Another disappeared. Happily no IFSD with us aboard. Lots of room for me and my sis to run around -- and a capacious flight deck that would put many modern condos to shame:}

tdracer

14th Nov 2013, 23:37

Pan Am ditched a 377 (aka. Boeing Trimotor)

:confused::confused::confused:

There is/was a Boeing Trimotor, and a Boeing 377. Very, very different airplanes. Boeing Trimotor was pre-WWII and could be mistaken at quick glance for the better known Ford Trimotor.

Boeing 377 was based on the B-29 and had four engine (aka Stratocruiser).

(Hows that for a thread drift :rolleyes:)

glofish

15th Nov 2013, 03:34

Per a new "Appendix K" to the FAA regulations, effective no later than Jan 1 2015, all new production Part 25 passenger aircraft will be subject to "ETOPS", regardless of the number of engines

Thanks tdracer, didn't know that.

It seems that some regulators come to similar conclusions as i pointed out earlier concerning extended operations for the multi-holers.
Now why would that be? Maybe because there were some decisions when losing one of four that needed a little looking into.

This what i slightly criticised and what you can abundantly read on this site: Some jockeys and operators are a little overconfident when it comes to the capability of their 4-holer limping on three. The regulators feel the need to intervene and put in some rules.
Never nice, but mostly provoked.

Capn Bloggs

15th Nov 2013, 03:36

Glofish, more like envious twin operators/manufacturers...

tdracer

15th Nov 2013, 03:49

Glofish, more like envious twin operators/manufacturers...

Capn, who exactly would that be? Showing compliance with the new 4 engine ETOPS regs is going to cost both Brands A and B millions.

No insight as to how Brand A plans to show compliance, but in the case of Brand B it's going to mean boring holes in the sky for hundreds of hours to show their four engine airplane operates just fine on three engines or other systems failures. It's not impossible to take credit for in-service experience, but it's very, very difficult.

New regulations cost money - often lots of it. Sometimes they improve safety. More often they just cost money. :ugh:

RatherBeFlying

15th Nov 2013, 07:03

The moniker Boeing Trimotor was applied to the 377 because of the time it spent with three operating engines.\;)

glofish

15th Nov 2013, 07:22

Glofish, more like envious twin operators/manufacturers...

Silly argument.
We basically discussed two incidents, the BA and the EK one, one on a B and the other on a A. Both airlines operate 2-holers and 4-holers.

Why would either manufacturer or airline be envious?

Fly3

15th Nov 2013, 07:44

I was led to believe that the new rules for 3/4 engines are Extended Range Operations (EROPS) and are going to be 240 minutes from a suitable airport because that is the maximum cargo fire suppression time on most models.

RAT 5

15th Nov 2013, 09:49

Ref: G.B.Sense.
RAT 5 "Am I missing something?"

- yes

So a 737 has to be within 1200 miles on two but a quad, with all of it's extensive systems redundancy, has to be within 1200 miles on three.
It's definitely a worry that people think its ok to run around on one because its "ETOPS" but down to three engines on a quad is dangerous - weird world - glad I'm retiring.
barking !!

Just to correct your mistaken impression of my thinking. I did not say a 3/4 engine a/c had to be within 1200nm of suitable. I do not know the rules and that is why I asked the question. It has not been answered by those in the know, so I am still ignorant of the rules. I do not profess to pontificate on things about which I do not know 100% of facts. IMHO maybe, but not factual statements.

742

15th Nov 2013, 10:05

It seems that some regulators come to similar conclusions as i pointed out
earlier concerning extended operations for the multi-holers.
Now why would that be? Maybe because there were some decisions when losing one of four that needed a little looking into.

glofish --

As fly3 points out, the "ETOPS" expansion to quads is focused on systems and fires. They will still have the option to press on with 3, so the regulators are not in your camp.

BOAC

15th Nov 2013, 10:20

Assuming Fly3 is correct (and that is my understanding also) the extension of an ETOPS scenario to 3/4 engine a/c has little to do with this current discussion. I would have expected most crews to 'want' somewhere to go if they have a hold fire so as long as these a/c remain within the 'circle' there is nothing to stop continuing with a 'suitable' other failure.

BluSdUp

15th Nov 2013, 12:58

Hi Fellow Aviators!
Lovely to spend a standby day educating myself on this tread.
I have to say i like commanding a medium twin in Europe with no acars, why , You say :my craft, my crew and my conclusion and execution ! ( as per sop aom and regs. Of course)

About the case:
When in Parliament on the other hand some bright fella might have sugested a pit-stop in Tolouse the home of the Airbus ,for a fuelpump (s) replasment and bar replenisment , crewchange. Before charging on , max delay 2 hrs!?

On the other issue, : Engine shutdown or failiur , no damage or unrelated fail/mel :
"Captain, nr 1 of 4 has failed ,now we have 3 left and statistics tells me we shall not have another engine fail the next 10 million hrs, by the time we are out of fuel, so as per conferancecall and sop I sugest we press on to destination, Sir!
Correct, OR,:in a short time the rest of the fueltonoiceconwerters are going silent.
Try Airtransat, Aircanada , Ba 777 , KLM . When one engine fails statistics tells us the chances of the next engine to fail has gone up to one in 5000 . Ie the next 5 sec, min or 5 HRS ,the next one WILL fail , statisticaly.
Point is , You divert anyway. In this case to Airbus Main.

Sober Lark

15th Nov 2013, 13:25

B, statistics say they will continue to destination.

BluSdUp

15th Nov 2013, 13:52

Mr Sober
As You have LH experiance and I not, can you tell me wich flight plan system they, You use that brings us to dest on one less engine? It aint LIDO or pilotbrief,that I know.
And did the Ba 747 and the A-380 make it to dest. .?
Again -1 eng ,divert,
Questtion is were, say 737-800 OSL - Canary, :mtow 78 000kg ,max land 65andabit. N-1 at v2 winter , Scandiland, :ba good o/1000 ,
Hahn Frankfurt :cavok 10c.
I goto HHN, why , 11 tons to burn, no dump,
In Hahn I get arrested.
Why?

Sober Lark

15th Nov 2013, 16:12

Hi B, No LH for me. I work in statistics and probability.

suninmyeyes

15th Nov 2013, 18:17

Glofish you wrote:

Some jockeys and operators are a little overconfident when it comes to the capability of their 4-holer limping on three.

I don't think you get it yet. They are not "limping" on three. The 4 engined aircraft have in effect become a Tristar except as the Tristar could not get much further than London to Bangor the 4 engine planes with an engine out are far more capable. They have adequate redundancy and will not crash if they lose another engine. In the event they did lose another engine and were down to two they would have to land at the nearest suitable airport, just as a twin has to if it loses an engine.

As regards previous comments asking what would happen if there was damage and a sudden leak started. The crew will be doing regular fuel checks and monitoring the situation and would be well aware of their drift down altitude should another engine fail and will be planning for it.

Their seems to be an attitude prevalent on this forum that if an aircraft has a technical problem it should immediately divert and land. That is actually a cop out. It takes skill to assess a situation and continue safely and legally to destination. The armchair theorists have their own judgement and do not appear to understand MEL, ADDs or commercial operations. Quite a few technical problems do have a checklist that direct the crew to land at the nearest suitable airport. A single engine failure on a 4 engine aircraft does not merit this. I write this as someone with many years experience on the 747.

SMOC

15th Nov 2013, 20:36

I think a few people (non airlines pilots) here are getting ETOPS confused, it was created to make flying safer for twins, enhanced maintenance practices, flight planning, enroute weather etc the reason being should a twin have an engine failure it must divert and have the fuel to do it, these rules will enhance 3-4 engine ops but you're dreaming if you think the 3-4 engine aircraft will be required to divert to the nearest suitable like a twin, they will likely continue to the furthest suitable and land with whatever company/aviation body reserves that are required for a 3-4 engine landing at destination. Just like EK and BA (without the incorrect fuel balancing procedure) they would have made the destination had they been using the Boeing fuel balance procedure.

ETOPS isn't you must divert with an engine failure, it's should you have a engine failure the aviation body has made rules that the route is safe with suitable diversion airfields within range. And they've put maintenance practices in place to make failures even more unlikely.

FCOMs/QRHs/SOPs are "Land ASAP" or "plan to land at the nearest suitable" airfield.

Twin - Engine fail - ETOPS airfield "check", QRH - Land at nearest suitable.

3-4 engine - Engine fail - ETOPS airfields "check", QRH - "checklist complete"

The whole fire suppression thing is a nice planning stage exercise as we've seen on several occasions planes on fire don't last 30 mins let alone 240!

DozyWannabe

16th Nov 2013, 00:30

Remember the L1011 that took off from MIA over the Caribbean losing oil on all three engines, shutting two down and had to restart them because the last one was seizing? I think it was Delta a long time ago. Mechanic didn't replace O rings with his oil change.

Bubbers -

https://en.wikipedia.org/wiki/Eastern_Air_Lines_Flight_855

I remember reading about that one - though as Super VC-10 points out, it was an EAL jet, not Delta.

A similar mistake led to three of four engines failing on a BAe 146 of the Queen's Flight in 1997:

BBC News | UK | Three engines fail on Royal plane (http://news.bbc.co.uk/1/hi/uk/32691.stm)

(Though I'm aware that some wags consider the 146 to be equipped not so much with four engines as five APUs... :E)

Why would either manufacturer or airline be envious?

My thoughts exactly.

The crew will be doing regular fuel checks and monitoring the situation and would be well aware of their drift down altitude should another engine fail and will be planning for it.

Well, one would hope so - but even the most skilled pilots can sometimes misjudge a situation. The Captain of the Air Transat A330 that dead-sticked into the Azores did a bang-up job in saving his aircraft and for that he deserves full credit, but on the other hand he also spent a significant amount of time insisting that the abnormal fuel indications must have been a computer error, and ordered the crossfeed valves to be opened. Don't get me wrong, as a techie myself I can completely understand a little healthy scepticism when it comes to technology - but refusing to give it the benefit of the doubt and plan accordingly meant that he exposed his passengers and crew to significantly more danger than would otherwise have been the case.

Una Due Tfc

16th Nov 2013, 01:09

I have had 2 747s with engine failures continue to dest in the last couple of years. I'm not naming the carriers (they were not Emirates or BA) no emergency declared, both descended and slowed, nothing major

lomapaseo

16th Nov 2013, 02:59

Eventually more (not all) will understand the true statistics. That the odds of not being able to safely divert with an initial engine out failure condition is higher for a quad than a twin per flight segment.

Thankfully the odds for either are quite low and I wouldn't expect more than one in 20 years.

rottenray

16th Nov 2013, 03:27

... what if the An-225 loses an engine? The dreaded 5-engine approach is soon to follow...

Decisions....decisions....
http://t1.gstatic.com/images?q=tbn:ANd9GcRQ6h2hTOBrZm2pD2spIDtlKzqM1tYyZEHWCGUobcc Kn8vr3_nxWg
...or the even-more-dreaded 17-engine approach!

I think I read somewhere - perhaps in this very thread - that Kuwait was a logistics choice more than a fuel choice.

742

16th Nov 2013, 05:24

That the odds of not being able to safely divert with an initial engine out
failure condition is higher for a quad than a twin per flight segment.

I am sorry, but I have to ask. What universe are you living in?

stilton

16th Nov 2013, 05:41

A universe where rational thought no longer exists.

Amazing that, to some twins are considered safer because there's 'less to go wrong'

I suppose when both engines have failed they are as safe as possible :ugh:

glofish

16th Nov 2013, 13:55

stilton

At the same level we can state:

Amazing that, to some, 4-holers having lost one of them seem as safe as Pampers because nothing more can go wrong to harm it .......

See the irony?

No one basically compared a twin to a 4-holer her. A twin losing a donkey is on emergency and will go down asap, ETOPS or 60min, whatever.
A 4-holer has the option to continue until it runs dry. Sure thing.
BUT, what we said, and tried to provide some arguments, and have been sometimes ridiculed as if we were pure beginners, is that this still needs careful consideration, because it IS an abnormal situation after all.

Simply take this as a contribution to a discussion and not an admonishment! Some reactions are more than condescending.

Leaves the question as to with which skipper you would prefer to be a FO raising some concern about a decision: The one listening to your argument, even very conservative ones, or the one telling you off in a condescending way, pointing out to the prowesses of a 4-holer ......

SMOC

16th Nov 2013, 15:32

glofish,

The manual (Part A) states actions in the event of an engine failure and continued flight, most crew know this usually by memory however it would obviously be reviewed in a real event.

Once all those boxes are ticked (consider a second engine failure, have other systems been affected other than what's a result of the engine shutdown, fuel req on 3, fuel req on 2, terrain on 3, terrain on 2, alternates/weather etc including the commander considers it safe to do so).

I'm sure most concerns would have been raised and discussed simply by going through Part A, both crew would clearly be in the same loop and if the 'go' boxes can't be met the prowess of a 4 holer won't cut it either. If someone thinks it's unsafe to continue on 3 they better not even leave the gate when boarding a twin. The rules that allow a twin to depart the gate are just like the rules that allow a 3-4 engine A/C with an engine failure to continue.

glofish

16th Nov 2013, 15:42

If someone thinks it's unsafe to continue on 3 they better not even leave the gate when boarding a twin

Quod erat demonstrandum (ref my comment about overconfidence, not 4 vs 2 holes).

Nothing more to add. I rest my case.

BOAC

16th Nov 2013, 15:47

Chucking a match on the fire - is it safe to continue on 2, glo?

Good Business Sense

16th Nov 2013, 16:06

I rest my case - you don't have a case to rest !

TeachMe

16th Nov 2013, 16:18

Just SLF and trust the right decision was made in this situation

One thing I note is that in the discussions above that some do not understand conditional statistics. I suggest some posters read up on it.

Next, derived from this, a question: Is a 747 / 380 on two engines after a random initial failure and no diversion followed by a second random failure just as flyable, stable and 'safe' as a 777 on one engine (assuming for both no more engine failures) ? If not, then a drop from 3 to 2 on a 747 / 380 is more 'seious' than a drop from 2 to 1 on a 777.

Yet another question: To what extent is it possible to know fully and completely the cause of an engine failure before a mechanic opens up the engine?

If it is 100% possible in some situations, then in those situations the chance of a second failure is equal to the chance of the initial random failure.

If it is not possible to know 100%, then there must be assumed a greater risk of a second or further failure.

I know stats, but not piloting, so I do not have the full answers to these questions, but they are central to situations such as this.

John Farley

16th Nov 2013, 16:45

Some may think this relevant to this thread, others may not.

Jet engines typically need a pump for them to run in a high altitude cruise.

Providing there is gravity feed (fuel tank above engine) the engine will run at low level without a pump.

The max altitude for running without a pump is type dependant.

So unless you want to land at a very high level please be assured you can relight a donk as you saunter into land if that donk has flamed out at height because it has no pump.

Good Business Sense

16th Nov 2013, 16:47

Teachme

Next, derived from this, a question: Is a 747 / 380 on two engines after a random initial failure and no diversion followed by a second random failure just as flyable, stable and 'safe' as a 777 on one engine (assuming for both no more engine failures)

Ref. the above - is it valid to discuss/compare an aircraft which has had TWO separate failures with an aircraft that's just had ONE ? Should we not discuss the 747 / 380 with two engine failures compared to a 777 with two engine failures ..... using your criteria of "random failure" - Apples to apples and all that !

..... I guess we can talk about the probability of a 747 losing two and the probability of a 777 losing two (I'm told it's the same) but moving to the real world .... what is the effect ? Bearing in mind we have been unable to think of an incident/accident where a four engine jet aircraft "continuing" on three after a "random failure" has had a problem - it's been going on since the mid fifties !

:)

barit1

16th Nov 2013, 17:19

Possibly germane to this discussion: National Airlines Flight 27 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/National_Airlines_Flight_27)

(DC-10) When #3 fan disintegrated, one fan blade was thrown into the accessory gearbox of #1 engine, stopping its fuel pump so it immediately flamed out. #2 also received FOD but continued to run. The aircraft landed successfully at ABQ.

Dimitris

16th Nov 2013, 18:09

Lets say engine reliability = 0.99
2 engine: 0.99^2 = 0.9801
4 engine: 0.99^4 = 0.9605

i.e. 4 engine is less reliable in engine terms than a 2 engine. Thats how it has been since forever. What changed over time is engine reliability, thus what failure mode is more important (engine failure itself or outcome of engine failure)
An engine failure can be anything. Fuel pump or turbine disk failure (uncontained)

A fuel pump failure is unlikely to create further problems. A turbine disk failure may create more problems. But both are engine failures. See recent A380 or old times DC-10 ( the one that burst the hydraulic lines).

Back in the days that engines were less reliable, more engines were a short of 'redundancy' because they were unreliable (compared to nowadays).

Now that engine reliability is higher, probability of losing engine is low, thus you don't need many engines cause even if you lose one (extremely unlikely event), its extremely unlikely that you loose one again (due to engine reliability).

Problem arises by the likelihood of damage to other systems due to engine failure (for example turbine disk failure). In that respect a 4 engine plane is more likely to get damaged due to one of its engines failing, because it has more engines. Furthermore engine failure of any short is distracting to the crew, ATC etc etc, i.e. other things can go wrong and line up the holes.

So nowdays with extremely reliable engines, there is less benefit from engine redundancy (3-4 instead of 2) because adding more engines reduces the reliability of the overall system (plane). That doesn't mean that its not safe to have more engines, it means that there is a trade off between 'how many engines' and 'what do I have to gain'. Back in the days you gained redundancy, nowadays you gain other things. The only sure thing is that engines are more reliable and that makes aviation safer and planes better.

If the fuel is contaminated, or if the same person installed all fuel pumps wrong in all engines is a different story and there are other safeguards against that. If the same person installs and checks all the fuel pumps on a 2 or a 4 or a 256 engine plane, then all engine reliability figures fly off the window because chance of engine failure is not based on independent probabilities anymore.

btw, I'm not saying that the number of engines during design depends only on the above. The above are the reasons that ETOPS became possible.

DaveReidUK

16th Nov 2013, 18:15

Possibly germane to this discussion

Hard to see the relevance, as we're talking about a potential non-common-mode multiple engine failure, rather than an instance where one engine fails and damages another as a consequence.

BluSdUp

16th Nov 2013, 18:21

Mr Sober Lark
With regards to my statment about the Next engine failing after the first,within 5 min to 5 hrs,in one of 5000 cases ,I forgot about the Dc 10 and the Fokker 70 ( klm Torino to) sas dc9 etc.
My middel name is M for Murphy, ic the Devils advocaat, to many students has said, Noway!?.....You are full of it,
They are right , I am , full of old stories that will repeat themself.

Historic fact, :if one engine fails ,the next Statisticaly will fail inside 5 hrs.the next 5000 hrs . Not in 10 million hrs.
With regards to the case and BA they monitored the rest of the engines and the maint. Records and could provide the Commander with confirmation that he was safer then a Etops twin to go to destination.

galaxy flyer

16th Nov 2013, 19:35

barit1

Was the National incident the one where the F/E was suspected of inducing a failure of the engine speed controls? Not a "normal" failure, if so.

barit1

16th Nov 2013, 20:57

DaveReidUK - Correct. This was sequential common cause failures.

galaxy flyer - Yes, I think the entire crew was curious about a possible failure mode; and were party to the N1 indicator failure scenario, which they simulated by pulling a c/b.

What is not really known is why the #3 fan accelerated to a destructive (resonance) speed. GE was never able to replicate that.

donpizmeov

17th Nov 2013, 02:05

I think the real question is what would the proclaimers have done?

The don

glofish

17th Nov 2013, 06:58

don

I would have probably carried on just the same way, because it must have made sense. Not without constantly having in the back of my mind what Tech Me has nicely put though, and that is what I tried to bring up for discussion and not dissection.

It worries me that this is brushed aside so quickly and fervently, not to say condescendingly.

Sometimes it reminds me of the ominous “ … four legs good, two legs bad …”, only to see the same proclaimers later trying to stand up on two legs themselves ……..

donpizmeov

17th Nov 2013, 07:17

Sorry Glofish,

I was thinking more of the spectacle wearing Scot brothers. I know they would walk 500 miles, am just wondering if they would try for the 5000 as stated in the title. It was posted early in the morning ok, don't judge me!!!:E

I can guarantee that the dudes in the 380 didn't just continue on regardless. Lots of thought, consideration, calculations and consultation would have taken place while decision making.

As an aside the continuation policy and its relevant considerations are taught when doing 340 or 380 courses. So the flight deck members have a very good handle of what's required.

wiggy

17th Nov 2013, 08:28

don

Don't worry, some of us got the joke..:E

I can guarantee that the dudes in the 380 didn't just continue on regardless. Lots of thought, consideration, calculations and consultation would have taken place while decision making.

Sounds reasonable to me.

stilton

17th Nov 2013, 09:34

To have one engine remaining on any multi engine jet transport is a serious situation, the big twins are certified to operate on one and land as soon as possible.

This is why ETOPS was invented, to cater and allow for an unthinkable possibility in the age of three and four engine jets.

Those earlier aircraft had built in redundancy allowing you to continue with the loss of one powerplant.

Nothing has changed except the 'twin minded' assume every engine failure is an emergency regardless of how many you have remaining.

suninmyeyes

17th Nov 2013, 10:52

Ian W

17th Nov 2013, 13:30

In the last 6 years I can think of 3 accidents in twin engined aircraft caused by total engine failure in flight, a 777, An Airbus A320 and a Boeing 737.

Since 4 engine commercial jet airliners started flying in the 1960s I cannot think of one accident on a 4 engined jet airliner due to multiple engine failure resulting in insufficient thrust to remain airborne. I am not counting fuel exhaustion as those were not mechanical failures of the engine.

Engines were not so reliable back in those days and 707's and the early 747's did sometimes lose one or two engines. There is a big difference between an uncontained engine failure with adjacent damage which is the scenario some people seem to be thinking about on this forum and an engine that has been shut down by the flight crew due to low oil pressure, high vibration, high temperature etc.

In the past before the days of the internet a lot of 4 engined aircraft would have carried on to destination after an engine failure with their passengers blissfully ignorant and the general public unaware. The pilots would have used their skill and judgement to decide whether to continue or not and unqualified people on forums who have never flown jet airliners would not be thinking they knew better than the pilots. :)

Do not be too sure that such common mode failures cannot happen. Your engines are reliable now with a lot of software support. If something happens that is outside what the system designer assumed likely then you may suddenly find that you have a common mode software failure

"Incident: Airbridge Cargo B748 near Hong Kong on Jul 31st 2013, both left hand engines surged at same time, one right hand engine damaged too"

Incident: Airbridge Cargo B748 near Hong Kong on Jul 31st 2013, both left hand engines surged at same time, one right hand engine damaged too (http://avherald.com/h?article=46679ba1)

This poorly handled icing software glitch could have occurred in the ITCZ over mid-Atlantic then the story may have had a different outcome.

This is called a common mode failure. ALL aircraft with software controls that have been built on prior assumptions - even if the software is dual designed for resilience - can suffer these failures. Yes they are rare but when a software failure like this occurs ALL your software controlled super reliable engines are likely to go. Are even your engineers on telemetry to your engines aware of the wrong assumptions made by the analysts, software designers, programmers and verification testers?

And yes this affects aircraft with all numbers of engines - but in this case having more engines does not necessarily save you. You could be flying aircraft with 4 glass jawed engines and be totally unaware until the 'wrong' sequence of events hit them and the software makes the wrong decision.

As I said earlier Fault tolerance, resilience and reliability are interesting fields and basic frequentist statistics bear NO relation to probabilities of failure in complex fault trees.

moggiee

17th Nov 2013, 15:36

I'd have no problem being on that flight.
I'd have been pretty comfortable with it, too, I think.

To be fair to the crew none of us were there - THEY make the decisions dependent upon the information that THEY had available to them from a multitude of sources.

Whether it be DODAR, FORDEC, GRADE, DECIDE or some other process, they will have had a decision making process to follow that will have weighed up the risk and benefits of the situation. It is, after all, why they are on board in the first place.

DozyWannabe

17th Nov 2013, 17:18

In the last 6 years I can think of 3 accidents in twin engined aircraft caused by total engine failure in flight, a 777, An Airbus A320 and a Boeing 737.

As far as the first two examples go, was the first one (BA038) not caused by ice restricting the fuel flow to both engines, and as such as 4-holer in the same situation would have been equally vulnerable? Likewise the other two, in which birdstrike and precipitation ingress were the problems.

This poorly handled icing software glitch could have occurred in the ITCZ over mid-Atlantic then the story may have had a different outcome.

I can't see anything in the linked page which explicitly specifies a software "glitch". Do you have information confirming that?

tdracer

17th Nov 2013, 18:45

This poorly handled icing software glitch could have occurred in the ITCZ over mid-Atlantic then the story may have had a different outcome.

This is called a common mode failure. ALL aircraft with software controls that have been built on prior assumptions - even if the software is dual designed for resilience - can suffer these failures. Yes they are rare but when a software failure like this occurs ALL your software controlled super reliable engines are likely to go. Are even your engineers on telemetry to your engines aware of the wrong assumptions made by the analysts, software designers, programmers and verification testers?

I'm right in the middle of that program, and I can absolutely guarantee that event had absolutely nothing to do with software - glitch or otherwise. You're basically just making :mad: up.

It is related to Ice Crystal Icing - a poorly understood phenomena that has also affected CF6, PW2000, and GE90 engines over the years.
GE is looking at addressing the GEnx issue using software, but that's just because that can be done quicker and cheaper than a hardware change. It's also far from a given that the s/w change will actually work. :ugh:

procede

17th Nov 2013, 20:21

Since 4 engine commercial jet airliners started flying in the 1960s I cannot think of one accident on a 4 engined jet airliner due to multiple engine failure resulting in insufficient thrust to remain airborne. I am not counting fuel exhaustion as those were not mechanical failures of the engine.

I can think of one: El Al 1862 at AMS on 04-10-1992, though why it eventually crashed was damage tot the leading edge device. Loss of engines was not exactly independant though...

Good Business Sense

17th Nov 2013, 20:49

Hi Procede,

The thread has been about losing an engine and continuing to destination with no major issues rather than one event causing multiple failures - and nobody has come up with an example of that

Schnowzer

18th Nov 2013, 01:26

It is simple probabilities; it doesn't matter how many engines you have, the risk of losing one stays about the same but if you do lose one on a twin you have lost half your thrust and will probably have to divert whereas on a 4 only a quarter is lost and you will probably not. On a 380 losing one you still can miss all the terrain in the world by a healthy margin. The crew did exactly what any seasoned aviator would be expected to do with a single system failure and what the regulations were designed to allow for.

Using the divert argument above you could have a hundred engines and some would think you should divert when down to 99 and you know what they would be right but only if continuing would have resulted in taking a meteorite strike!

This thread confirms 2 things to me that I already knew; 1. how many people like to pretend to be experts on anonymous websites and 2. how incapable of logical thought some real pilots actually are.

To quote from a dead stick F16 pilot when told his Mayday was number 2 behind a B52 with an engine failure "yikes, that will be the dreaded 7 engine approach!"

suninmyeyes

18th Nov 2013, 03:12

Procede

I am aware of the El Al but did not include it as although it lost two engines the accident was not caused by insufficient thrust to remain airborne. They accelerated and raised the flaps and in the 747 when the flaps are up the outboard ailerons are locked out. The combination of damage to the lift devices on the wing and lock out of outboard ailerons led to a loss of roll control.

I agree that all 4 engines can be knocked out by something like volcanic ash. However I reiterate that no 4 engine jet airliner to my knowledge has been lost by continuing after an engine failure and having a further loss of engine power.

tdracer

18th Nov 2013, 03:47

I agree that all 4 engines can be knocked out by something like volcanic ash. However I reiterate that no 4 engine jet airliner to my knowledge has been lost by continuing after an engine failure and having a further loss of engine power.

Kalitta B742 at Bogota on Jul 7th 2008

Crash: Kalitta B742 at Bogota on Jul 7th 2008, engine fire, impacted a farm house (http://avherald.com/h?article=40950475)

- a non-recoverable surge of engine #4 during rotation resulting in the loss of engine power, the combined effects of an inefficient high pressure turbine, excessive slack space at the tips of the blades, reduced chord and leading edges of the fan blades and the high altitude contributed to the engine failure.

- an undetermined anomaly in engine #1 which manifested itsself in engine surges and resulted in the loss of engine power. The failure to maintain proper minimum aircraft speed during climb out and the resulting use of emergency extra power exposed the anomaly leading to the engine failure.

Granted, this was not a case of a 4 banger attempting to continue to destination after loosing an engine at TO, but it did crash due to the independent failure of two engines.

I can think of a number of incidents and accidents due to multiple engine failures due to 'common cause' - usually environmental such as adverse weather, volcanic ash, and birds. While I suppose one could make a reasonable argument that more than 2 engines is an advantage with birds (less likely to get critical bird strikes on all engines), for extreme weather or volcanic ash the number of engines makes little difference. Just off the top of my head I know of at least two 747 four engine power loss events due to ash, and two 747 three engine power loss events due to extreme weather (fortunately all ended happily).

I can't think of a single twin accident due to independent power loss on both engines, yet it took me literally seconds so come up with a 4 engine accident due to independent power loss on two engines (it helped that I was involved in the investigation :E)

suninmyeyes

18th Nov 2013, 12:02

tdracer

Good points all well made. I was thinking more of scheduled passenger flights but the Kalitta is interesting. On a normal takeoff after an engine failure it should not be necessary to increase thrust on the remaining engines. If I remember correctly the 747/2 thrust was not governed with the Pratt and Whitney JT9 engines and if firewalled they were only guaranteed to give 5 minutes of thrust.

By maintaining a speed below V2 after lift off, raising the nose to 17 degress resulting in activation of the the stick shaker and firewalling the engines the crew doomed themselves. The second engine failure was in effect caused by the crew.

lomapaseo

18th Nov 2013, 13:13

I don't see the value of arguing between two vs four when considering the subject event (neither an incident nor an accident in my book).

The consideration is mostly the risk of anything else going wrong either dependently or independently and its probable effect on the flight.

It seems that almost all of us focus solely on the remaining engines and their probability of failure. Although I've not seen any comments assessing the impact on a 5 hr flight should a second engine fail on a quad.

I'm not prepared to take sides in what-if arguments of this kind since all the data I've seen regarding independent failures in cruise says that at worst it's an extremely small contributor to overall in-flight risk for all fleets.

Craggenmore

18th Nov 2013, 13:35

The A380 is fantastic at this sort of minor problem.

I trust you all have heard EK's aircraft order from this afternoon..?

50 more 380's ordered so a total of 101 on order with 39 already in service.

(+ 150 777 X's)

742

18th Nov 2013, 13:58

It seems that almost all of us focus solely on the remaining engines and
their probability of failure. Although I've not seen any comments assessing the impact on a 5 hr flight should a second engine fail on a quad.

lomapaseo:

In FAA land the second engine failure in a quad is addressed by FAR 121.193, compliance with which is a part of preflight planning.

Ian W

18th Nov 2013, 16:38

I'm right in the middle of that program, and I can absolutely guarantee that event had absolutely nothing to do with software - glitch or otherwise. You're basically just making :mad: up.

It is related to Ice Crystal Icing - a poorly understood phenomena that has also affected CF6, PW2000, and GE90 engines over the years.
GE is looking at addressing the GEnx issue using software, but that's just because that can be done quicker and cheaper than a hardware change. It's also far from a given that the s/w change will actually work. :ugh:

I am not "making stuff up" the information came from that unreliable source Aviation Week.

"Boeing says the flight test effort is focused on “verifying operational elements” of a change to the engine control software. The testing included monitoring the development of ice crystals on the GEnx-2Bs powering RC021, one of the company’s test airframes that has recently been used to evaluate fuel system upgrades and other performance improvements. The fully-instrumented aircraft was originally designated for 747-8I launch customer Lufthansa, but was retained as a test asset after the German carrier opted not to take the modified airframe.The software changes to the GEnx-2B full authority digital engine control unit are designed to help the engine itself detect the presence of ice crystals when the aircraft is flying through a convective weather system. If detected, the new algorithms will schedule variable bleed valves to open and eject ice crystals that may have built up in the area aft of the fan, or in the flowpath to the core. The modification to the GEnx control logic leverages similar changes made to improve the ability of the CF6 to operate in similar icing conditions."

Boeing, GE Test Upgrades To Counter Engine Icing (http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_08_23_2013_p0-609559.xml)

And to return to my original point if there is an error in that 'new' software (like an incorrect assumption on the effects of icing (e.g, whether liquid water can be found at -40C above FL400 - it can) and therefore what changes are required in the engine; then the engines' software could all make the same incorrect decision on icing. I am not saying that they will I am saying that they could, there is no such thing as error free software or error free design (unless of course you have 'fixed the last bug' ) The software design/code itself becomes the common mode failure point and the number of engines is immaterial.

tdracer

18th Nov 2013, 17:02

Ian, where exactly in that Av Week did you see reference to a s/w 'glitch', as I again quote your post:
This poorly handled icing software glitch could have occurred in the ITCZ over mid-Atlantic then the story may have had a different outcome.

A software "glitch" is when the software does not function as intended. The GEnx software in this event worked exactly as intended.

Since you obviously didn't read my response, I'll repeat it:
The problem is Ice Crystal Icing (ICI) - which is fundamentally a hardware problem. ICI can cause ice to form internal to the engine core, in areas where it's normally too hot for ice to form. When this ice sheds, it can damage blades and/or quench the burner. GE is trying to address the ICI problem using software changes, because if they have to change the hardware it'll be hugely expensive and take a long time. They may or may not be successful with this approach.

MikeBanahan

18th Nov 2013, 21:51

I'll bite on this though I tend to keep quiet, but my background in safety critical systems and formal proof of correctness of software gives me a certain amount of practical experience.

The software industry is a strange place. Much commercial software is of appalling quality and really is a disgrace to the profession. If anything tangible, say buildings or mechanical things were built so atrociously, it would be plain to any observer what a festering lash-up was being presented.

However, just because a lot of software is of lamentable quality does not imply that, therefore, all software is equally bad.

The software industry arguably seriously dates back to the late 1950s (I would personally pick the introduction of Algol 60 as a watermark but you can argue with that; its genesis dates it to the middle 50s).

In academic areas the skills and techniques necessary to produce software that is equally as well engineered as any counterpart in the civil, aeronautical or electronic engineering domains were vigorously pursued from around that time.

There is NO magic whatsoever in producing software to any arbitrary quality level you choose. The methods and techniques are 'well known', i.e. more than one person exists who understands them (sorry, academic joke in that last clause). As in any field of engineering, however, quality comes at a cost.

If you are prepared to pay the cost you can get the quality, just as in any field. Because software of such quality is rarely required outside of safety critical systems, the practitioners are not found on every street corner but you can find them and train them and implement the end-to-end quality and traceability that would be expected in other fields.

When that is done you are no more likely to get bad software than you are to get a defective compressor blade or contaminated fuel. And it so happens that the investment in quality has the unusual characteristic that the software can be endlessly duplicated at no cost (apart from audit and trace), unlike mechanical components where the cost is not only in the design but also the duplication.

Rather than assuming that all software is broken, or faulty or defective, it's smarter not to wag a finger in the direction of the software but instead to ask searching questions about HOW it was engineered from end to end and to what quality standards, just as you would with a mechanical component.

There is nothing unique about software. It's an engineered product like any other and can be produced to similar quality levels.

glofish

19th Nov 2013, 05:18

I can't think of a single twin accident due to independent power loss on both engines, yet it took me literally seconds so come up with a 4 engine accident due to independent power loss on two engines (it helped that I was involved in the investigation )

I'd like to thank you a second time tdracer.

You are able to sustain with experience what i tried to bring up concerning this incident.
It is certainly possible and can even make sense to continue with a 4-pod after loss of one. I simply wanted to point out that the risk involved might be higher than a lot of fellow pros insinuate on this pages. So extended continuation should maybe be considered more conservatively.

Lomeopaso stated rightfully that is is NOT a matter of comparison 2 vs 4 engines. A twin is on emergency when losing one, a 4-pot is in an abnormal situation and not in that presumed cosy "continue" situation. Your quote underlines that.

One additional word to the mentioned monitoring and advising by the Tech departments while on abnormal situations or with tech troubles: Every advise we get on ACARS today has a nice footer with a disclaimer about responsibility. This leaves me with some mixed feelings about remote advise, not to say control .....
Up there we are still alone in matter of decision making. Many companies like to pretend that they only advise us, but in effect many of them apply more pressure than help. But when the s#!t hits the fan they leave us out in the rain.

tdracers comment should make some of us reconsider. A 4-holer is a more comfortable aircraft to operate than a twin. But even a 4-holer gets into a abnormal situation when it loses one pot.

HighAndFlighty

19th Nov 2013, 07:23

I'm surprised that nobody has mentioned QF32. IIRC that little drama started out with a single (albeit uncontained) engine failure on a 380.

Good Business Sense

19th Nov 2013, 10:32

HighandFlighty

Once again the thread is about shutting one down on a four engine and continuing on enroute with three and then having a further problem leading to an incident/accident - QF32 quite different

White Knight

19th Nov 2013, 11:17

lomapaseo

19th Nov 2013, 19:05

tdracers comment should make some of us reconsider. A 4-holer is a more comfortable aircraft to operate than a twin. But even a 4-holer gets into a abnormal situation when it loses one pot.

Agree

but the deciding difference to me is that when a twin loses 1 the response is direct against an SOP

when a quad loses one, more involved consideration is needed and the variety of actions is greater.

I still have no opinions in this incidence but maintain that our armchair judgements bear no significance other than what-ifs

glofish

20th Nov 2013, 09:57

There are exceptions to the general rule...
I'm surprised that nobody has mentioned QF32. IIRC that little drama started out with a single (albeit uncontained) engine failure on a 380.

Contained...

Uncontained...

DIFFERENCE maybe?????

It is actually an interesting case.

Uncontained, yes, but basically only on one side. It shows that an engine on the same side might be affected by an uncontained failure (i.e. AF Concorde) of its neighbor. Here the second engine refused to respond to the throttles. Remains to prove why the third engine, the one that did no longer respond as well but was located on the other side, was influenced by the uncontained failure. Was it software influence? Then the software glitches mentioned earlier on this thread come into play. Else why would an engine on the opposite side be influenced? Or does tdracers experience come into play?

Anyway, as i said an interesting case ........

misd-agin

20th Nov 2013, 12:44

Question for any A380 pilots - how much altitude would you need to lose with the loss of one engine?

Off the top of my head I'd say a twin has to descend 10-15,000'. Engine out can be in the high teens or low-mid 20's for the weights I've checked.

Megaton

20th Nov 2013, 13:05

Question for any A380 pilots - how much altitude would you need to lose with the loss of one engine?

Can't answer for A380 pilots but on the 747 at representative long-range weights, level off would be in the region of FL300 so altitude loss might only be couple of thousand feet if it's relatively early in the flight.

Eau de Boeing

20th Nov 2013, 13:23

On a 13/14 hour flight typical level off would be around FL320/340 depending on weight, temp, flight planning etc.

DozyWannabe

20th Nov 2013, 15:29

Rather than assuming that all software is broken, or faulty or defective, it's smarter not to wag a finger in the direction of the software but instead to ask searching questions about HOW it was engineered from end to end and to what quality standards, just as you would with a mechanical component.

There is nothing unique about software. It's an engineered product like any other and can be produced to similar quality levels.

Nicely put, Mike.

I've been saying much the same thing on these forums for quite some time now. There's simply no comparison between the kind of software we use in homes and businesses - which until recently tended to be fairly free-form in design and loosely specified, and the kind of formally-specified and aggressively tested real-time software that goes into aviation use, among other safety-critical sectors.

That said, the kind of aggressive testing and integration management used in safety-critical systems from the get-go is starting to find its way into modern mainstream software development, and the take-up has been growing exponentially for the last decade or so. It's not dissimilar to how mechanical tech derived from aviation has been filtering into other uses (e.g. anti-lock braking systems on motor vehicles).

I'm surprised that nobody has mentioned QF32. IIRC that little drama started out with a single (albeit uncontained) engine failure on a 380.

And yet in that incident the crew elected to stay in the air for an hour or two - despite their proximity to the airport - to work through the ECAM and thus discover which systems were still functioning. I recommend reading Captain De Crespigny's book on the subject - it makes for entertaining and fascinating reading.

barit1

20th Nov 2013, 17:07

DozyWannabe:the (QF32) crew elected to stay in the air for an hour or two

They were well above max ldg weight (mass), had no flaps, and only one t/r. Had to burn off a bunch of Jet-A to have a prayer of a successful landing.

On the other hand their left wing was leaking like mad, leading to limited roll authority! :eek:

DozyWannabe

20th Nov 2013, 17:21

They were well above max ldg weight (mass), had no flaps, and only one t/r. Had to burn off a bunch of Jet-A to have a prayer of a successful landing.

As the book has it, it wasn't just burning off fuel that led to the "keep flying" decision, it was taking the time to work through the ECAM actions (of which there were over a hundred) - this enabled them to be *certain* of what was working and what wasn't before they attempted a landing. Kudos to the Captain, who freely admits in his book that his instinct was to get on the ground ASAP, but that he was persuaded to keep flying by the rest of his crew and use that time to assess the aircraft's condition thoroughly.

Good Business Sense

20th Nov 2013, 17:55

... not withstanding accidents like swissair, my position is generally, "don't make a drama out of a crisis" i.e. if you've got a problem, don't make it a bigger one.

In my opinion the biggest problem in these kind of events is knowing exactly what your problem is - I never liked too many what ifs getting in the way of the "known facts". I think gathering information on which to make a good decision is one of the most difficult things - then there is the time available to do so.

On the QF with the problems they had they may have felt that it was a pretty sure thing that they would have gone off the end if they'd turned straight back in etc - on the other hand with fuel leaks etc ......

If they'd immediately turned back in they would have had no idea, at that stage, of the state of the aircraft and its systems and, therefore, the immediate return could have been suicidal for all sorts of reasons - don't forget we're looking at it with hindsight - in the first 10-20 minutes he had no idea what was wrong with his aircraft.

DozyWannabe

20th Nov 2013, 17:58

On the QF with the problems they had they may have felt that it was a pretty sure thing that they would have gone off the end if they'd turned straight back in etc - on the other hand with fuel leaks etc ...

As I said, read the book. The first thing they worked out was the fuel situation, which determined how long they could keep flying to iron out all the other potential issues.

White Knight

21st Nov 2013, 00:04

Quote:
Quote:
There are exceptions to the general rule...
I'm surprised that nobody has mentioned QF32. IIRC that little drama started out with a single (albeit uncontained) engine failure on a 380.
Contained...

Uncontained...

DIFFERENCE maybe?????

It is actually an interesting case.

Uncontained, yes, but basically only on one side. It shows that an engine on the same side might be affected by an uncontained failure (i.e. AF Concorde) of its neighbor. Here the second engine refused to respond to the throttles. Remains to prove why the third engine, the one that did no longer respond as well but was located on the other side, was influenced by the uncontained failure. Was it software influence? Then the software glitches mentioned earlier on this thread come into play. Else why would an engine on the opposite side be influenced? Or does tdracers experience come into play?

Anyway, as i said an interesting case ........

The QF 380 was an interesting case. My point however regarding the contained v uncontained failure is that THIS thread is about the EK 380 that had a contained failure and continued for some hours. Why are posters confusing the issues here?

glofish

21st Nov 2013, 02:20

WK

There is no confusion. Your analysis might be correct, but what a lot of contributors are saying, and what a lot of 4-potters keep brushing under the table, is that when an incident occurs, it might be contained for a while, seemingly under control, but it can turn into a uncontained/multiple incident in a whim.

The tendency on 4-holers to continue simply because they are allowed is what is on discussion (not their superiority to twins).
tdracer brought up some troubling facts, i brought up my admittedly controversial conclusion.

Concerning QF32, the problem was nicely handled. It could however have turned into a tragedy in a fraction of a second. The SR111 accident showed how fast an incident turns into a catastrophe. The fact that they stayed up in the air for so long is discussed, not only lauded, but they stayed close to a runway all the time, could abort the ECAM frenzy at any moment helped them.

The question remains is if they would have continued for multiple hours? No, certainly not, it looked too serious. But where to draw the line for continued operation with one incident? Where does the statistics and Murphy put the chances of an escalation, even an unrelated one like tdracer brings up, that suddenly puts you in an uncomfortable (QF) situation?

The more i read these contributions, the more i feel that a twin , even under ETOPS, represents an almost safer operation. At least we/they go down asap and by that eliminate more of Mr. Murphy and the ugly stats ........
Take this statement with a pinch of salt though! :)

Good Business Sense

21st Nov 2013, 02:59

At least we/they go down asap

Couldn't agree with you more ! :D

the more i feel that a twin , even under ETOPS, represents an almost safer operation

oh, dear ??? :=

glofish

21st Nov 2013, 03:45

GBS

please quote the whole statement!

It was based on the remark "The more i read these contributions ...."
and this includes your latest.

What about the pinch of salt? Good business sense, but none of humour it seems.

tdracer

21st Nov 2013, 03:50

White Knight - I don't think it's confusion in so much as predictable thread drift. The perceived wisdom (or lack there of) of continuing on after an engine out on a quad pretty much inevitably morphed into a discussion of the relative merits of a quad vs. a twin.

Back in the early days of ETOPS, there were lots of studies related to engine failures, when they happened, and when did they contribute to significant incidents or accidents. For example, it was discovered that relatively few engine failures occurred during cruise - most occurred during takeoff/initial climb, or top of descent/descent - when ETOPS wasn't a significant concern.

But - in what was probably the most controversial finding - the probability of an accident as the result of a non-common cause engine failure was greater on a quad or a tri than a twin.
The reason was pretty simple: Commercial Airliners are designed to fly just fine after the shutdown of one engine - in fact when we do system safety assessments, we consider basic engine shutdowns no worse than major (even on a twin). But, an engine can do something worse than simply quit - it can catch fire or fail uncontained - and failures of that type have caused a number of crashes over the years. The more engines on an aircraft, the greater the odds that one of those engines will fail in a catastrophic manner (I said it was controversial :}).

Now I fully expect to get flamed for posting this by the "quad centric" group, but the studies were vetted by a number of experts and was eventually accepted by the Feds as the foundation of current ETOPS.

Listen, I work twins and quads (at the moment 747, 757, and 767 - in the past 737 classics and 777). They are all safe, and there are relative advantages both ways. But it's not only simplistic to state that adding engines makes an aircraft safer, its not supported by the data.:=

DaveReidUK

21st Nov 2013, 07:05

But - in what was probably the most controversial finding - the probability of an accident as the result of a non-common cause engine failure was greater on a quad or a tri than a twin.I suspect that you haven't expressed that the way you intended.

A "a non-common cause engine failure" implies more than one engine failing, right ?

So do you mean the relative probability of multiple engine failures on a quad vs a twin ?

Or do you mean, given multiple engine failures, the relative probability of an accident ? Nobody could possibly argue that that's higher with 2 remaining engines than with none.

Looks like we're back in compound/conditional probability territory - I'd really like to see some numbers, if anybody has some.

Good Business Sense

21st Nov 2013, 09:40

What about the pinch of salt?

Glofish, it's good to see someone enjoy the aircraft they are flying but prior to this thread, over your 257 posts on pprune, you've made your opinion of four engined aircraft very clear ... so, "pinch" ?

tdracer

21st Nov 2013, 14:12

A "a non-common cause engine failure" implies more than one engine failing, right ?

So do you mean the relative probability of multiple engine failures on a quad vs a twin ?

Or do you mean, given multiple engine failures, the relative probability of an accident ? Nobody could possibly argue that that's higher with 2 remaining engines than with none.Perhaps I didn't express that very well, but it is what I meant. Most engine failures are benign - the engine quits making thrust or the flight crew sees something abnormal and shuts it down. Since all currently certified jet airliners can operate safely with one engine out, the aircraft continues flying and lands safely.
However, there is a small subset of engine failures that are not benign - uncontained disc failures, engine fires, etc. While we design to minimize the threat, these non-benign failures have resulted in a number of crashes over the years. What I was trying to say was, the greater the number of engines on an aircraft, the greater the risk of experiencing one of these non-benign engine failures that would result in a catastrophic outcome.

The reason I brought in 'non common cause' is that common cause failures - by definition - can affect all engines on an aircraft so it really doesn't matter how many engines you have. If the mechanic leaves the o-rings out of all the engines, your fuel load is so contaminated that the engines can't function properly, or you fly through volcanic ash and all the engines flame out, 4 vs. 2 doesn't matter much.

procede

21st Nov 2013, 14:22

or you fly through volcanic ash and all the engines flame out, 4 vs. 2 doesn't matter much.With 4 engines there is a higher probability that you will still have an engine producing thrust. At least that is what BA and KLM found.

BA 9: British Airways Flight 9 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/British_Airways_Flight_9)
KLM 867: KLM Flight 867 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/KLM_Flight_867)

lomapaseo

21st Nov 2013, 14:54

tdracer

What I was trying to say was, the greater the number of engines on an aircraft, the greater the risk of experiencing one of these non-benign engine failures that would result in a catastrophic outcome.

Agree :ok:

The problems generally occur during the landing phase mostly due to workload increases.

There is not much data on enroute problems with multiple engines as I have said before, but just studying the crew responses in all phases of flight leads me to suspect that twins are not any less safe then quads and quads certainly have more engine annomalies per flight

tdracer

21st Nov 2013, 15:14

With 4 engines there is a higher probability that you will still have an engine producing thrust. At least that is what BA and KLM found.

BA 9: British Airways Flight 9 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/British_Airways_Flight_9)
KLM 867: KLM Flight 867 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/KLM_Flight_867)

I won't bother to read what's in the Wiki article because I have first hand knowledge: In both BA and KLM, all four engines failed and quit producing thrust - at pretty close to the same time (in the case of KLM I was involved in the investigation).

In both cases the flight crew was able to get engines restarted after they dropped out of the ash cloud, but make no mistake - all four engines failed. Not really a valid 2 vs. 4 data point.

lomapaseo

21st Nov 2013, 21:24

tdracer
re: KLM Flight 867 and BA Flt 9

In both cases the flight crew was able to get engines restarted after they dropped out of the ash cloud

I believe only after repeated tries and a few prayers. Some speculation that the hot and cold cycles of multiple restart attempts might have shed some of the glassy stuff off the innards , but like you said not a 2 vs 4 data arguement

DozyWannabe

21st Nov 2013, 22:06

Also re: KLM Flight 867 and BA Flt 9, and apropos of nothing - as it's not really relevant to the thread, but if I recall correctly, the damage was such that three of the four engines on the BA jet and all four on the KLM jet needed to be replaced.

Pugilistic Animus

21st Nov 2013, 22:19

This is gonna turn into a 2000 post thread, just like the BA on three.:E

tdracer

21st Nov 2013, 22:47

I believe only after repeated tries and a few prayers.

In the case of KLM, when we looked at the data afterwards it appears that they aborted what would have been successful starts if they'd just left them alone (it was autostart equipped). However you are likely correct that the hot/cold cycles helped clear some of the glass that formed in the turbine, making subsequent start attempts 'more' successful.

The newer Boeing airplanes (787 and 747-8) have improved 'autostart is progressing' EICAS indications, in part due what happened during the KLM ash encounter.

Giolla

21st Nov 2013, 23:05

femanvate

22nd Nov 2013, 03:22

A 4-engine plane can safely fly with one shut down, however, when you have dozens of airports around you, drop an engine and decide to still head out over thousands of miles of cold ocean, I fail to understand why the Capt did not choose to turn around.
The cause of the failure was determined after the jet landed.
Sure, it's inconvenient and expensive to turn back, but how could he be so sure the remaining engines would not experience any issues and commit his passengers lives to that assumption for several hours, without knowing 100% why the failure happened.

BobM2

22nd Nov 2013, 03:47

On 20th of November, a chartered plane from SLM flew on one engine from SPL to Paramaribo, a trip of 9hrs plus.
This was a 767, after take off from SPL there was a loud bang and one of the two engines packed up.
The AC continued its flight to Paramaribo, where it landed safely.
No further news.

Further news appears to be that engine didn't fail. Just burped shortly after takeoff, then normal operation across the pond:

Incident: Euro Atlantic B763 at Amsterdam on Nov 20th 2013, engine surge on departure, continued across Atlantic (http://www.avherald.com/h?article=46bcdcc9&opt=0)

SMOC

22nd Nov 2013, 05:18

how could he be so sure the remaining engines would not experience any issues and commit his passengers lives to that assumption for several hours, without knowing 100% why the failure happened.

So two A380s take off from Dubai and one has an engine failure hours later should the other one divert as well?

Good Business Sense

22nd Nov 2013, 08:23

TIme to shut the thread ..... no pilots left ... only experts who have never flown an aircraft

Flyingmac

22nd Nov 2013, 08:31

With passengers in the back I believe the convenience of service facilities
and whether you have to buy room nights should not be the issue. The only issue
should be "Which airport is the safest option at this point."

I do most of my flying with one engine. Even with no engine problems, the answer to the question above is "The one I just left".:) I still press on.

Bergerie1

22nd Nov 2013, 09:02

Good Business Sense

You are so right!

ironbutt57

22nd Nov 2013, 11:45

to sum it all up.....SO WHAT!!!...

llondel

23rd Nov 2013, 02:14

I can't think of a single twin accident due to independent power loss on both engines, yet it took me literally seconds so come up with a 4 engine accident due to independent power loss on two engines (it helped that I was involved in the investigation )

What about Kegworth? Stretching it a bit, I admit, and they were already on the home stretch, but one stopped producing power because it went bang, the other because it was shut down.

tdracer

23rd Nov 2013, 03:00

What about Kegworth? Stretching it a bit, I admit, and they were already on the home stretch, but one stopped producing power because it went bang, the other because it was shut down.

Stretching it quite a bit I'd say. Big difference between shutting down a perfectly good engine in response to the failure of the other engine, and a legitimate independent failure of both engines.

Granted, it wouldn't be nearly as bad had it happened on a 4 banger, but adding engines to protect against the crew shutting down the wrong engine after a failure isn't a particularly convincing argument :eek:

742

23rd Nov 2013, 12:26

"A 4-engine plane can safely fly with one shut down, however, when you have dozens of airports around you, drop an engine and decide to still head out over thousands of miles of cold ocean, I fail to understand why the Capt did not choose to turn around."

You miss the point. A 4 engine airplane can often safely fly with TWO engines shut down. Thus loss of 1 is an issue to manage, and it might be prudently managed by pressing on -- IAW with 70 years of industry experience.

IcePack

23rd Nov 2013, 18:30

Let's face it 3 engine ferries are normal.:)

Sober Lark

23rd Nov 2013, 20:30

Were the flight crew qualified, current, and experienced to carry out 3 engine flights of such a distance with passengers and freight? Consideration of a second engine failure procedure and performance implications must have made for an unrestful crossing.

As a passenger it's not all about stir fried lobster, flat beds, showers and vanity tables.

donpizmeov

23rd Nov 2013, 20:49

Sober Lark,

Yep they are all trained and qualified in three ENG continuation, and well supported by a despatch team (also trained) and Engineering team (in real time and also trained). The companies OPs Manual addresses the when/what and how it can and can not be done (approved of course by overseeing authority). Its all well thought out and planned for as the aircraft is designed to be able to do it.
And as a PAX it is all about the Lie flat bed, cocktails and showers (you wont find that on the twin), as they not qualified for anything else. Nor should they be.

Megaton

23rd Nov 2013, 21:19

TIme to shut the thread ..... no pilots left ... only experts who have never flown an aircraft

Correct. And of the few pilots that have posted recently, not many seem to have any four-engine experience.

slowjet

24th Nov 2013, 08:23

Agreed. That's why I like Ironbutt's post =236= . Are the Mods on leave or something ? Of course, you don't have to read everything. I gave up after a few posts but looked in, now and again, to see where it was all going. Astonishing drivel. Lose one donk out of four (?), yeah, drills etc, re-plan for lower level, satisfy the CRM pundits with mnemonical diarrhoe like FORDEC,NOSDEC, FLIGHTDEC (I don't know what dek)-----------make a committee decision (don't forget to consult the Junior Cabin Attendant on the hours issue) and THEN, (not a mnemonic) summon the CA looking after you & ask what's for supper . On thread, these guys did everything right. Text book example for the rest of us to admire & replocate.

400drvr

24th Nov 2013, 08:46

Flarepilot

[QUOTE]lose engine...worry for 12 hours get close to home./QUOTE]

Time to worry is when your down to 2 engines and could have landed an hour ago. In all seriousness if you are established enroute and need to do a precautionary shutdown, of course you consider your options. The obvious being the destination and enroute weather. Next I would consider my options for landing short if need be, again check the weather. And if I were flying in South America I would check the MEA's over the Andes and ask for a reroute or if need be or land short of the destination. I really don't understand all the excitement about flying with an engine out.

Regards

barit1

24th Nov 2013, 14:17

Hmmm.

Within my failing memory, I recall an airline or two expressing reluctance to order the DC-10 or TriStar; Just how many customers would be comfortable flying the pond on fewer than four?

But that was then... :}

Wilbur60

27th Nov 2013, 07:26

Just go through '4R' drill.
Is it :
1. Realizable : Yes
2. Rentable : Of course
3. Regulation compliant : it is
4. Reasonable : Yes

Period.

staffanwikstroem

27th Nov 2013, 09:40

Me too, (not into double figures but nevertheless). What I miss in this discussion is one important thing. The service ceiling of the A380 on two engines.

Eau de Boeing

27th Nov 2013, 11:10

Depending on weight between FL180 and FL260 approx.

Time to close this and move on......:rolleyes:

awstruth

10th Dec 2013, 22:17

Couple of questions:
Would you allow your young children/grandchildren to fly on an airline that thought it OK to continue longhaul....as BA reportedly did....after an engine failure at 100 feet?
Would you be comfortable with them flying the 5000 miles the A380 completed on 3 engines as reported here?
Without question the A380 is a technological marvel, but if the situation had deteriorated and resulted in a loss of life incident/accident do you seriously think that the pilots would have company/industry/media/CAA or FAA support?
Are the pilots there to showcase their skills or are they there to safely transport the passengers ?
All of us must be mindful of company costs for obvious reasons.
But NO diversionary cost will ever approach an accident cost.
I suggest that by considering only the comfort and safety of the passengers that you protect the company's interest..and your own..by default.
And to the smug dopes who think SLF have no right to an opinion...who pays your wages?

Formerly: L1011 / B737 / B747 / B757 / B767
Currently: SLF (retired)