US FAA investigates Continental 777 engine failure at Newark
 

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

Before someone asks, this is from the NTSBs web-site:

GEE.

no, G.E.!

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?

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

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.:}

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.

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?

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

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.



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.

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:

Thanks for the clarification.

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 :)

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.)

Lomapaseo,

That reminds me of Donald Rumfelt's speach when he said::ok:

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:

I think the missing one is:

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

:confused: