US FAA investigates Continental 777 engine failure at Newark

[Zenj]

US FAA investigates Continental 777 engine failure at Newark
John Croft, Washington DC (21Mar07, 19:09 GMT, 231 words)

A US FAA investigation is underway into an apparent contained engine failure that caused a Continental Airlines Boeing 777-200ER to abort takeoff at New York Newark yesterday afternoon.

The aircraft, operating as flight 84 to Tel Aviv, was taking off on Newark’s runway 4L with 260 passengers and 16 crewmembers, when its right-side General Electric GE90-94B engine suffered the contained failure.

A GE spokeswoman says ground personnel observed “a flash of fire” from the number two engine during the takeoff roll, and the pilots abandoned the takeoff attempt after the engine lost power.

The aircraft was towed back to the gate.

According to FAA officials, debris exited the rear of the engine indicating a contained rather than an uncontained failure.

The airport closed the runway for over an hour to clean up the debris, a move that caused “some impact to operations”, says a FAA spokeswoman.

A substitute aircraft departed Newark for Tel Aviv later that night. Continental expected to have the 777 restored to service with a replacement engine by this evening.

GE, which is working with the FAA and Continental on the investigation, says this type of failure has not occurred on a GE90-94B engine before.

National Transportation Safety Board (NTSB) officials in New York verified that the incident does not appear to be a more severe uncontained engine failure, and as such, no NTSB investigation has been launched.

Source: Air Transport Intelligence news

[False Capture]

Before someone asks, this is from the NTSBs web-site:A “contained” engine failure is one in which components might separate inside the engine but either remain within the engine’s cases or exit the engine through the tail pipe. An “uncontained” engine failure can be more serious because pieces from the engine exit the engine at high speeds in other directions, posing potential danger to the aircraft structure and persons within the plane.

[bomarc]

GEE.

no, G.E.!

[Whitehatter]

Brings up the question concerning GE's desire to water down the blade-off tests for the GEnx.

Current requirements are that blade-off tests are done from the root of the blade, GE wants to certify their engines using a detonation further up the blade. This incident shows that current practice works just fine, so why compromise?

[barit1]

This failure may not involve the fan at all, in which case the blade-off test is immaterial.

[Arnie Dan Otherdump]

GE, me and the old lady next door all agree that a blade off test is not relevant in the containment issue. RR et al all end up with large lumps of metal lunging around the fan case several times trying desparately to get out after a failure. The clever bods at GE on the other hand have amply demonstrated that an impact causes the blade, in the bat of an eyelid, to revert to dust - hence kinetic energy gone in a flash ! . . That's what we reckon anyhow !

[lomapaseo]

GE, me and the old lady next door all agree that a blade off test is not relevant in the containment issue. RR et al all end up with large lumps of metal lunging around the fan case several times trying desparately to get out after a failure. The clever bods at GE on the other hand have amply demonstrated that an impact causes the blade, in the bat of an eyelid, to revert to dust - hence kinetic energy gone in a flash ! . . That's what we reckon anyhow
Right-on:ok:
except many of the adjacent blades also revert to dust leading to an imbalance tearing the engine off the wing. Strictly speaking there is no such thing as a containment test requirement in the regs. It's all about the blade out and resulting loads from the damage after the dust setlles.:}

[Whitehatter]

I threw that in as a discussion point. The EWR issue demonstrated that current testing works as it means the engines can survive an extreme event, so why change the way in which it's done?

I have no doubt that GE can produce engine casings which meet all current testing criteria, so why are they publicly trying to change the conditions for the GEnx? Strikes me as being something of an own-goal.

[barit1]

Couple of missing items here, mostly regarding UNSHROUDED rotors.
A common propeller must meet an overspeed test demonstration, 141% of takeoff RPM IIRC. If a blade separates above that speed, it's in the "extremely unlikely" category, thus beyond certification intent. However experience shows that in a worst-case situation, it can happen (http://www.ntsb.gov/ntsb/brief.asp?ev_id=21426&key=0).

I'm sure the GE36 (http://en.wikipedia.org/wiki/General_Electric_GE-36) and the like had to meet such an overspeed test if it were to be certified.

[lomapaseo]

Couple of missing items here, mostly regarding UNSHROUDED rotors.
A common propeller must meet an overspeed test demonstration, 141% of takeoff RPM IIRC. If a blade separates above that speed, it's in the "extremely unlikely" category, thus beyond certification intent. However experience shows that in a worst-case situation, it can happen.

I'm sure the GE36 and the like had to meet such an overspeed test if it were to be certified.

What do propellers have to do with this discussion:confused:

What does overspeed have to do with this discussion:confused:

What's a GE36?

[Fundi-Ya-Ndege]

I have seen the result of an uncontained failure of a CF6 on an A300 600 where compressor blades from the failed engine embedded themselves in the other one....
Seems like there was still enough energy for that after all.:)
Four engines are almost always better than two.:D

[lomapaseo]

I have seen the result of an uncontained failure of a CF6 on an A300 600 where compressor blades from the failed engine embedded themselves in the other one....
Seems like there was still enough energy for that after all.
..............

Really?, the most I've known of on the A300 is a few bits sticking into soft nacelle skin but never making it through to the actual engine insides.



.......

Four engines are almost always better than two.

Agree, you have 3 times the chance for nailing any two engines in an uncontained failure on a quad if that's what you mean by better.

[barit1]

What do propellers have to do with this discussion

What does overspeed have to do with this discussion

What's a GE36?

Matter of fact, as I mentioned earlier, fans (& propellers) are probably not germane to this CO GE90 incident. :rolleyes:

The GE36 was GE's UDF (Un-Ducted Fan) -- a response to high fuel prices of 25 years ago. While it had outstanding fuel burn, it was too noisy and too complex. :ugh:

[lomapaseo]

Matter of fact, as I mentioned earlier, fans (& propellers) are probably not germane to this CO GE90 incident.

The GE36 was GE's UDF (Un-Ducted Fan) -- a response to high fuel prices of 25 years ago. While it had outstanding fuel burn, it was too noisy and too complex.

Thanks for the clarification.

[Loose rivets]

GE, which is working with the FAA and Continental on the investigation, says this type of failure has not occurred on a GE90-94B engine before.

Mmmm.......so how does one plug "a type of failure that has not happened before" into an equation to assess ETOPS.

Not really a question, just the type of thing I mull over while on one engine and with a wet horizon in every direction.

[lomapaseo]

Mmmm.......so how does one plug "a type of failure that has not happened before" into an equation to assess ETOPS.

Not really a question, just the type of thing I mull over while on one engine and with a wet horizon in every direction.

When you fly you fly with a split of unknown mechanical risks (latent failures, wings about to fall off, etc.) and known risks, problems which are known and being addressed over a stipulated time period.

Thank goodness this is now known and will be fixed. However, it's generally the unknown ones that are going to get you, like forgetting to transfer fuel correctly between tanks :)

[barit1]

Just because it's a "type of failure has not occurred on a GE90-94B engine" doesn't mean it's totally unprecedented on other engine models. Thus it probably has been taken into account in ETOPS planning & analysis.

And it MAY NOT even be the engine's fault - possible maintenance error (wrong type of bolt, etc.), torque wrench out of calibration, etc. (I'm only speculating here, but these types of things have bitten many engines in the past.)

[False Capture]

Lomapaseo,

That reminds me of Donald Rumfelt's speach when he said:We know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns -- the ones we don't know we don't know."
:ok:

[barit1]

Rummy missed one. It's a 2X2 matrix:

We know that we know vs We know that we don't know

and

We don't know that we know vs We don't know that we don't know

:hmm:

[False Capture]

I think the missing one is:

unknown knowns; that is to say there are things we don't know that we do know.

:confused:

[olliew]

Or we think that we know what we know when in fact we have only assumed...

[Pax Vobiscum]

It ain't all the things you don't know that'll kill you. It's all the things you do know that ain't so.
Attributed to Theodore Sturgeon, but he probably lifted it from earlier sources ...

[passanger]

As a passanger on the flight here is my info on the subject of Flight 84 from Newark to Tel Aviv. As we were excellerating about one quater of the way down the runway we barely heard, over the normal loud takeoff sounds a "pop" or a "blast" followed by a loud vibration which shook the plane and stayed constant. I had a window seat opposit the failed enging and saw the wing breaks extend and the brakes being applied, the vibration was constant and a fellow passenger and I both guessed a blown tire. As the plane finally slowed the vibration stayed constant ruling out in our minds the tire theory. I recorded the sounds of the vibration with my digital video camera. The passangers stayed very calm. We sat on the runway for a minute or three with the vibration and sound. Then the motors were shut down. I have offered my videos to the FAA and Contential.

What every passanger wants to know is- what would have happened if this event occured, 10 seconds later- or just as we went wheels up... and what might have happened if this failure occured, say 30 seconds into the air? Could the good engine be excellerated fast enough to make up for the lost one?

Thoughts?

The airline was really excellent through this.

Passanger on Flight 84 March 20 2007

[Danny]

Passanger, many thanks for your observations. For your information, an engine failure at take off (EFATO) is probably one of the most practised manoeuvres that we as airline pilots carry out when in the simulator every six months.

It is fairly obvious from the incident where you were a passenger that the failure occurred before the aircraft reached it's V1 decision speed. Any major malfunction before the V1 speed and the aircraft can stop before running out of runway. Had the failure occurred after V1, the crew would have continued the take off.

On most aircraft we carry out performance calculations which take into account the weight of the aircraft, any deferred defects on the aircraft, the atmospheric conditions that affect the performance including temperature, wind direction and the condition of the runway whether dry, wet or contaminated, the length of the runway and stopway and any obstacles in the departure flightpath. Based on those calculations a power setting is derived which takes into consideration a catastrophic failure of an engine at the most critical time but which will allow the aircraft to continue its take-off within the remaining distance of the runway available and clear all obstacles during its climb to the minimum safe altitude. Also, if a reduced thrust take off had been used and one engine failed, the other engine can be brought up to full power should it be needed.

Once the aircraft has reached a safe altitude the crew would have carried out various drills to secure the failed engine, analysed the situation and made plans to return safely to an airport for a single engine landing. An emergency is usually declared when an engine fails after take-off and that allows Air Traffic Control and other aircraft in the vicinity on the same frequency to be aware of the situation and the aircraft will usually be give all necessary assistance to remain clear of other traffic.

I have never experience an engine failure in a jet and 99.9% of most airline pilots will never experience one for real. However, we are trained to handle the situation and no doubt there are few old hands on here who may have had the experience and will probably give you their accounts of the situation. Whilst an EFATO is not necessarily an emergency, it is handled as an "Abnormal Situation" and we have a very thick book of checklists which cover us for most "abnormal situaions", including an engine failure after take-off.

No doubt you were in good hands as it sounds as if the engine failure you experienced was handled "by the book". :D

[Austrian Simon]

What every passanger wants to know is- what would have happened if this event occured, 10 seconds later- or just as we went wheels up... and what might have happened if this failure occured, say 30 seconds into the air? Could the good engine be excellerated fast enough to make up for the lost one?


By law any airliner must be and actually is designed to be able to perform a safe takeoff and climb out with one engine out. So even if the engine failure had occured later past the decision speed (V1), after which a takeoff would be unconditionally continued, or already after becoming airborne, the airplane would be able to safely continue, get to a safe altitude and then return for a safe landing.

There have been many incidents like this before in history of aviation, that did not produce more than a footnote in the local newspaper.

Actually, the good (working) engine(s) will not be accelerated to make up for the failed engine. Each engine will be operated at its normal takeoff setting for every takeoff. If one engine fails, the other engine(s) will still supply that same amount of thrust, which is sufficient for safe continuation of the takeoff. That means, that on a twin airplane like the B777, you were on, each of the engines produces enough thrust to get and keep the airplane airborne. With both engines operating the B777 has therefore twice as much thrust available as is needed to lift her into the air.

Servus, Simon

[Zenj]

Danny

Excellent explanation on EFATO/RTO, I'm going to use this info on some of my expanations with your kind permission that is !

Passenger

I wouldnt mind getting a copy of that video, I dont know the size of the file buy if you are willing to share then let me know how you can upload it.

Its Interesting and thats what we always do in the SIM, but actual facts are usually different, we dont know yet what speed was RTO originated before the V1 but hats off for the crew for the good work.

I personally had a bird strike on rotation just 2 weeks ago and a loud bang was heard and folks around thought it was a tire failure, high temps / elevation gave us low thrust and had to fly for 1 hour to burn off for the allowed weight for landing, all went well eventually and 8 fan blades got ruptured and loose shingles followed, engine change was done.

I guess its all part of learning !

Zenj

[lotman1000]

Quote "Actually, the good (working) engine(s) will not be accelerated to make up for the failed engine"

Is that always the case? I have read of Automatic Power Restoration as a means of increasing RTOM on some aricraft

If the take-off is using minimum power settings (eg for noise) would the live engine need more power?

[uniuniunium]

"Quote "Actually, the good (working) engine(s) will not be accelerated to make up for the failed engine"

Is that always the case? I have read of Automatic Power Restoration as a means of increasing RTOM on some aricraft"

Depends entirely on the aircraft, installed options/software, and SOPs of that airline.

Picking from the T7 AFM:
"When making a reduced thrust takeoff, all performance requirements
are met with reduced thrust. If desired, the operating engine may be
increased to go-around thrust to improve performance."

[Austrian Simon]

I have read of Automatic Power Restoration as a means of increasing RTOM on some aricraft"

Some airplanes do indeed allow to accelerate the remaining engine(s) slightly. For example, MD-8x have about 800 lbs reserve thrust on the good engine (the failed JT8D-219 engine on the MD-83 just lost roughly 17800 lbs), which gets activated if ART is selected and no flex takeoff power is selected.

Similiar reserves are available for other airplanes, as you mentioned correctly, allowing the engine to be accelerated slightly beyond takeoff thrust for a very limited time. However, those thrust reserves are minimal compared to the lost thrust by the malfunctioning engine, just a few percent.

So the remaining engine(s) never make up for the failed engine, that's technically impossible and would immediately cause disintegration of the good engine(s).

Hence, my initial statement remains true (I did consider that sentence quite some time to not oversimplify the issue and then introduce a mistake by oversimplification).

Servus, Simon

[Stoic]

I see from another thread that a Delta twin lost an engine today and the Continental to Tel Aviv on this thread lost one on 20 March.

Can anyone enlighten me on the current running failure rate of ETOPS aircraft? I have always understood that ETOPS engine shutdowns are supposed to be so rare as to be negligible. But 2 failures in 3 weeks intuitively seems to me to be a rather high frequency.

Thanks in anticipation.

Stoic

[lotman1000]

Austrian Simon - thanks for the clarification.....



Stoic - I might be the first to point out that a shut-down is not necessarily a failure. I think the word is precautionary.

[Stoic]

<<I might be the first to point out that a shut-down is not necessarily a failure. I think the word is precautionary.>>

Is this not a semantic quibble? Surely with only two engines and one shut down (ie failing to produce thrust), there is only power available from one engine to reach a safe landing?

Regards

S

[lomapaseo]

<<I might be the first to point out that a shut-down is not necessarily a failure. I think the word is precautionary.>>

Is this not a semantic quibble? Surely with only two engines and one shut down (ie failing to produce thrust), there is only power available from one engine to reach a safe landing?

Regards

S

No problem in quibbling, since the issue is mostly statistical in nature and thus the term failure is dependent only on the outcome, safe flight, lower performance, increased pilot workload etc. etc.

Those that use the terms in assessing the impact on the flight consider all of the above and might not have used the word failure except in exact context. On the surface without additional details of engine symptoms, this shutdown might be entirely precautionary to prevent further damage.

And even with an engine shutdown on a twin there is more than adequate power to continue a flight to even the original destination.

I believe that we have talked the ETOPs subject to death before in other searchable threads so I'll just stick to surface issues of semantics here.

In researching IFSD (shutdown data) for both twins and quads it was noted that even with equally maintained engines (mixed fleets but same maintenance standards) that there were many more shutdowns per flight hour for quads then there was for twins. This suggests that the pilots were taking an abundance of precautionary shutdowns in Quads and it was for this reason that advice was given to consider only throttling back to idle a misbehaving engine in order to still have the use of its acessories (electrical, hydraulics)

[lotman1000]

Stoic

My dictionary says failure means that some fault, or lack of fuel, has caused a powerplant to stop functioning altogether, unexpectedly.

But I can shut down one in flight at any time, without a failure, if I estimate that I should. Example temperature warning or vibration indicated. That may be a sensor fault, only. I take a precaution.

If "semantics" means "no difference" I do not agree that this is semantics.

[pax2908]

I have read somewhere: "one does not shutdown a running engine". This statement suggests that IFSD means almost surely that the engine really has developed a problem that would likely cause it to fail if left running. So, of course I would be interested to learn of IFSD which were not triggered by a persistent engine malfunction.

[barit1]

Here is a sad example (http://aviation-safety.net/database/record.php?id=19890108-0&lang=en)in which a perfectly good engine was shut down. I believe it has become an object lesson for crew training.

[Stoic]

Thanks for the input. Can I go back to my original question?

"Can anyone enlighten me on the current running failure rate of ETOPS aircraft?"

In view of the comments, I shall modify it to ask: Can anyone enlighten me on the current running engine shutdown rate of ETOPS aircraft?

I agree that this is a matter of statistics. It seems to me intuitively that 2 incidents in 3 weeks where an aeroplane lost 50% of its thrust on an Atlantic ETOPS aircraft is rather high.

And barit you are correct. The British Midland M1 accident was used as a case study on my command course in 1990.

Regards

Stoic

[wmuflyguy]

I agree that this is a matter of statistics. It seems to me intuitively that 2 incidents in 3 weeks where an aeroplane lost 50% of its thrust on an Atlantic ETOPS aircraft is rather high.



Your looking at an irrelevant statistic. Just becuase 2 aircraft had engine failures is not relevant. You need to look at what types of engines were on the airplanes. If they were the same model of engine then you may have a point. I'm guessing the Delta plane was a 767 or 757 and thus a completely different engine than a CAL 777.

Also unless there is a common reason for the failure/shutdown of 2 engines of the same model, there isn't a reason to worry.

[Stoic]

Your looking at an irrelevant statistic. Just becuase 2 aircraft had engine failures is not relevant. You need to look at what types of engines were on the airplanes. If they were the same model of engine then you may have a point. I'm guessing the Delta plane was a 767 or 757 and thus a completely different engine than a CAL 777.


I am not at all sure that I can accept your explanation. It is certainly true that if the same model of engine gets sick and starts failing for the same reason, as happened I seem to remember to Cathay's 777s in the 90s (failing French gearboxes on Rolls Royce engines) then this is a catastrophic circumstance which must result in immediate grounding. However, if, for whatever reason, the general failure rate of twin-engined ETOPS aircraft is increasing (I am not claiming that it is, merely asking the question), there must be an increased risk of the exposure of the passengers and crew of ETOPS aircraft to the dubious pleasure of flying for prolonged periods on one engine over the sea. By 'failure' I mean the loss of power from 1 of the 2 available engines.

That was the reason I asked the question. Is the failure rate of ETOPS aircraft worldwide monitored?

Have you ever listened to (and tried to assist) the pilot of a single-engined aircraft over the Atlantic who is a couple of hours from Shannon and who has good reason to believe that his single engine is about to fail?

Regards

Stoic