1. I think you're misunderstanding the use of the phrase "simple failure". It's being coined as such to differentiate a flame-out in this case due to an apparent fuel pump failure and a catastrophic failure leading to multiple system failures.
2. Fully agree on this point
3. And here, but as I say in my previous post INPUT is helpful - or maybe I should say can be...
4. Unpleasantly present? Why? Surely you're used to it by now:}
5. Indeed. Deal with it...
6. Don't dig at all here. I agree with you.
7. Probability. Maybe no one should ever fly at all. Ever!

They did the job well. The only drama is from the ranks of prunists who have no idea of 380 ops!

glofish


And not only 380 ops - but 707, DC8, VC10, 747 and all 4 engine ops in general!

Glofish, your take on the issues are valid. Effective risk control is founded on an effective health and safety management system but that differs from country to country. We can look to frequency and severity data to judge risk but in most cases it is only after an accident when exhaustive investigation into casual factors, failures of compliance, proficiency and decision making processes results in remedial action.

Whilst we agree safety is paramount let us not forget the complex interaction of pilot and technology indicated a landing in Dubai which the A380 didn't achieve.

Which is why they flew instead to Kuwait, with enough notice for the company to postion another 380 there from Dubai, with a fresh crew so as to keep the operation running as best as possible.

Indeed safety is paramount and is how I fly my aeroplane. At the same time, as captains, we are also responsible for running an efficient and smooth operation... Taking all factors into account naturally!

Sounds like a Humphrey Appleby statement:} And again, it was a single engine failure. Everything else was working. No accident; which nullifies your above quote in this case!

Let me clarify some position:

There are two very separate issues at stake. One is the economical, the other the safety aspect. We all agree that we want safety to come before economics.

This thread deals with the legal possibility of 4-engined aircraft to continue almost unlimited with an engine failure. Although we should not compare with twins, because they are bound to land asap in the same situation, we can’t discard a comparison because ultimately the advantage of being able to continue represents an economical advantage, or no one in his right mind would continue with a failure of a vital component if not.

There is an inherent danger to blur the line between the two issues, safety and economics, if the possibility exists. The companies and their managers are only measured by profit, never by safety margins, unless there is an accident. Then suddenly however, the safety issue pops up in the public eye. Before it was only an issue to pilots, them being the only ones to effectively see the gap between the lip-service done to safety and the real situation. One smoking hole can change the whole game. Mostly only the pilots will be blamed, as they are almost always handily gone with the plane, and the companies and regulators get away with their fig-leaf and the public forgets everything with the next discount on air travel. Sometimes some managers are sacrified with the jockeys, as some mismanaged shortcuts are too blatant and very rarely a company goes completely down due to the same.

Having companies with their network and maintenance departments participate in decision making after failures is certainly logical, considering today’s data link capabilities. At the same time we can observe too many conflicts between companies and pilots concerning T&C’s and, going with it, the threatening culture that developped the last 20 years. The power shift from unions, which were admittedly often too short sighted, to profit maniacal management is obvious and not really enhancing safety.

Both of the recent engine failures on quads (BA, EK) led to diversions, even though they continued for many hours. So effectively, comparing to twin failures, the only advantage was getting closer to destination, but like twins not reaching it. So the advantage was merely an economical one because it allowed the company to prepare better for arrangements.

My point I am trying to make is: It certainly looks good to be able to prepare for such diversions and to choose a more appropriate airport with quads. In most cases the risk assessment would certainly allow a continuation. Sometimes though, the slight economical advantage fades compared to the increase in safety margin vs. routine operation.

I uphold my suspicion that (taking into account the above) the “advice” (and subtle pressure) from the company to continue, paired with the less strong position (protection) of today’s skippers leads to more biased decisions, more risk taking.

An engine failure remains a serious malfunction!

And I would agree with you 100% here.

This thread however is about a single engine failure on an EK380 - it's been brought to a totally different level here - and the subsequent continuation of flight for several hours. WHAT is the big deal? The RISK was assessed by the experienced PIC.
It is. I have had the experience a few times thanks, but all in pistons.... The point is that it is how the rest of the flight is managed isn't it?

glofish:But not as serious as burning the last few Kg of fuel.

Statistically, a "simple" engine failure, with no evident secondary damage, is not a contributor to the quad accident database. (I won't include the training accidents like the early DL DC-8 at MSY.

Again, you gotta pick your battles. The 5000-mile battle is becoming Quixotic - tilting at windmills. :(

Lets put it into context , are we advocating going back to 90 mins ETOPS on a twin. If its safe enough for 300 pax on ONE engine with 240 mins ETOPS whats the problem with 3 engines within reasonable distance of a suitable diversion if there was another problem ?

BVCU you have made the mistake of trying to argue reason and logic; I hope you have spotted your mistake and will promise not to do it again.

The thing which makes me chuckle is that there are now hundreds of posts about a precautionary shutdown; technically the engine didn't even fail. Many aircraft have run with zippo oil for hours but when you have 4 why take the risk!

Amber cautions (ASNA) , Red warnings(ASAP). single engine fail - neither , not a concern for the most part.

Hi White Knight, to the best of my knowledge the only A380 occurrence classification of 'accident' relates to VH-OQA.

SQ26 (9V-SKG) didn't 'push on' towards Frankfurt on 3.

As others have already said as long as safety was duly considered, there's no reason not to think of economy. One of the benefits of a four is to be able to do these trips.

Why is this thread is still going on?
 

I am not a pilot but I am involved in the design of safety related systems. I take advantage of the strong safety culture and detailed analysis of incidents in order (I hope) to learn lessons that are generally applicable. Which is why I browse pprune. What I can't understand is why this thread is dragging on. Two basic things seem to be overlooked.

1. Safe is not absence of all risk. There is no system in which there is no risk whatsoever. Safety is normally defined as freedom from unacceptable risk. This may be subjective but it is grounded in the real world.

2. The best person to judge a situation is a trained person on the spot. Analysing decisions based on partial information afterwards is futile and criticism is inadvisable unless the facts are known and the decision concerned is clearly unreasonable from the information available at the time.

In this case the best placed person made a decision based on his analysis of the risks. I am sure this analysis included the nature of the engine problem and whether this problem made other engine failures likely. From an engineering perspective unless the nature of the failure was itself likely to cause other probems or indicative of a common failure I cannot see how this decision can be anything but reasonable. A culture in which decisions are needlessly second guessed and criticised undermines safety by inhibitting confidence to make necessary decisions.

The central question to inform this debate is this:

Q1: Does observing ONE engine failure change the statistical likelihood of observing ANOTHER FAILURE later in the same flight? Hint: Fuel issues, bad maintenance procedures, batch fatigue failures.

And then - more interesting -

Q2: Does the PIC of an Airbus 380 have the training and information to validly answer Q1?

Unfortunately, I would say that the A380 does not yet have enough flight hours for statistical induction alone to answer either Q1 or Q2. As I am not a pilot, I would guess in those conditions better inconveniently safe than sorry. But then my fearfulness, bad eyesight and low IQ provide a good reason why I am not found at the pointy end :)

Edmund that airplane underwent extensive testing before certification, furthermore this was an IFSD not just a failure

PiggyBack


You are right. I flew 4 engine aircraft for over 30 years and I am amazed at how many people continue this pointless discussion. It really is time to stop.

Edmundroland, working in the interpretation of numerical data myself, I'm of the same opinion.

Piggyback, the starting point in deriving probabilities is to determine ways in which we can arrive at a measure of likelihood. We can look at the relative frequency with which the event in question occurred in the past. The subject of discussion is the recently developed A380 and a single event where it is logical that combinations of events were considered by automation and on the ground back seat drivers to press on towards destination.

For most of those 30 years you mention Bergerie1, I'd imagine you enjoyed the independence to made your own decisions.

Make no mistake; ONLY the PIC makes the final decision with regards to an issue like this. Sure, Network Control or whatever any airline calls it can be contacted for INPUT. But... Commander makes the final decision! Same now as it would have been 30 years ago except now we have more tools to use and consult!

ETOPS was perused by both Boeing and Scarebus so they could sell big twins to airlines to operate the Atlantic and Pacific more economically, with the comparable safety to the quads they replaced.
Now, that Twins flying ULR is the norm, it would seem that some want to limit the Quad operation to that of the twin.
A quad continuing on three suffers another engine failure. It now drifts down and diverts to a planned enroute ALTN, exactly the same as any Twin would do after a single engine failure.
A twin on a 207min ETOPS flight over the pole suffers an engine failure. It now drifts down and all on board wish they were flying in a quad.

donpizmeov
 

Glad I'm not the only one with that opinion.

Consider the NEXT failure, in a twin you are gliding, in a Quad you just may limp to somewhere. :E

Twin: Probability of second engine failure = xx * 1

Quad: Probability of second engine failure = xx * 3

:O

I don't think there's been a single case of a failure of ETOPS basic principles - i.e. a second engine failure - unless you count Air Transat Flight 236 - Wikipedia, the free encyclopedia.

Yes, and the probablility in a single is 0 - so clearly a single is infinitely safer! Lies, Damned Lies, Statistics...

(xx)quad vs (xx)twin and "the next failure"
 

This value of xx should be less when there are ETOPS ratings and procedures involved.

Either environmental or common-servicing-error reasons could also come into play to make two failures on a quad more likely than just xx-squared.

When discussing this it might be better to consider not the number of accidents due to 3/4 or 1/2 of the engines working, or 2/4-or-2/2 failing, but rather to the incidences of these failures. From that, it might be clear whether we're overdue for the first accident to occur due to engine failures taking place a long way from safety in a twin.

Very roughly, with ~1000 ETOPS flights per day, and a few reported failures per year, it seems that ~1:100,000 flights have failures, and so a double failure might only be expected every ~10,000 years. If this is valid, then the current practice should be safe enough.

Even a glider can fly :rolleyes:
It depends....
A quad on one engine will probably have problems maintaining altitude depending on weight. But it will have a better chance of getting to a suitable landing site than a twin on none.

Oh it can fly on *none* - see Gimli, and the quad-flameout in a volcalic ash cloud - but it will certainly be flying downwards. The rate-of-descent is what matters, and having one working donkey will certainly help in that regard.

Yes, a quad can fly on one, but only in a shallow glide. Can even fly on none if needs be!

https://en.wikipedia.org/wiki/British_Airways_Flight_9

Gimli was a twin, btw

Stop Press: Quad flies on one
 

http://1000aircraftphotos.com/Contri...avidJ/9578.jpg

P&W's Boeing 299Z testbed with T34 turboprop in the nose. :}

But Sir, that not a quad.

Pedant! Beancounter!

Is that the one Lord King tried to buy?

(when asked, with all the twins coming into service, why BA was still buying 4-engined aircraft, he supposedly responded with "because they don't make them with five!")

Part of the risk analysis of the 4 engine argument is a conservative assessment of the unknown. Zero risk is unattainable. On your remaining engines you still have wear out, infant mortality and random failure mode. When you mentioned lies and stratistics HDRW, I laughed when I also recall one of the models most commonly used in deciding on chances of failure of 4, 3, 2, 1 is the Monte Carlo Simulation (named after the gambling resort).

Perhaps the 'per flight' risk in the subject of this discussion was calculated as being low and that is why they decided to 'push on'. The data and engineering judgement so far (EK this incident of push on and SQ return) indicates there is not yet a consistent set of ground rules.

I'm not convinced that we need a rule, although it might quiet down the after incident challenges.

Too many what-ifs that are best handled today by pilots considering their resources both on-the-ground and in-the air.

then just to prepare for deep thinking arguments, why do we need an EROPs rule ? Has it saved anything ?

As you might suspect I see any diversion or air-turn-back as an increased risk as well as continuing.

Who can forget the A340 demonstrator at various airshows with "FOUR ENGINES FOR LONG HAUL" scrawled along the belt line in 3 metre high letters!!

That didn't last long but, then again, neither did the A340!

Not to mention a well-known UK airline that used to market the same concept:

http://www.flightglobal.com/blogs/wp...455-121296.jpg

Well until they bought their A330s. :O

losing engines....
 

Airbus 380 loses engine, goes 5000 miles.

Airbus 380 loses 2 engines, goes 10,000 miles. :8

Airbus 380 loses 3 engines, goes 15,000 miles. :8:8

Airbus 380 loses 4 engines, goes 20,000 miles. :8:8:8

;);) DoT

Simple question. Does the one engine inoperative checklist finish with the words; "land at the nearest suitable airport"?

Simple answer if you can't be bothered to read the thread George Class.


NO.....

Following it's diversion to Kuwait on the 26th Oct, the aircraft departed for it's original destination, Dubai on 28th Oct.