Posted on 06/06/2006 9:54:34 PM PDT by UNGN
General Electric is investigating the cause of an apparent uncontained engine failure which caused extensive damage to an American Airlines Boeing 767-200 at Los Angeles on Friday.
The aircraft (N330AA) was undergoing a ground run-up of the (left) No.1 engine when the problem occurred. The CF6-80A was being tested after the crew bringing the aircraft in from the New York reported abnormal power response from the engine during the flight.
Reports say the engine was at more than 90% power when the failure occurred, either in the shaft or the high pressure turbine (HPT) area. Judging by images of the incident that have since appeared on the Internet, it appears that an HPT disc ruptured, puncturing the fuel tank in the wing near the trailing edge, slicing partially through the belly of the aircraft and damaging the keel beam. The No.2 engine was also damaged by the exploding debris and the fuel tank on the right wing punctured.
The wing puncture also caused fuel to be spilled on the tarmac, and that along with a fuel line rupture caused a major fire which engulfed the wing and the rear fuselage before it was put out. Fortunately a Los Angeles airport fire department was close by, and got the fire under control while the the maintenance crew escaped The damage to the wing trailing edge, flaps, aft fuselage, fuel tanks on both sides and the keel beam makes it likely the aircraft will be declared a write-off. The surrounding runways and taxiways were closed off for some time immediately after the incident while a FOD search was carried out. Parts of the second HPT disc were reportedly still missing as of yesterday.
The CF6-80 has been hit by similar issues in the past, and as recently as January 2003 was the subject of a US Federal Aviation Administration airworthiness directive (AD) calling for inspections of the HPT disc. The AD was prompted by an incident on 8 December, 2002, when a 767-200 equipped with GE CF6-80A series engines experienced an uncontained failure of a stage 1 HPT rotor disc during climb. The FAA said at the time the “results of the investigation indicated that the stage 1 HPT rotor disc failure was the result of a crack that initiated in an aft corner edge of the bottom of a dovetail slot. The crack propagated in fatigue to critical crack size, and subsequently resulted in disc rupture and separation.”
The FAA also notes that in September 2000, a U.S. operator experienced a similar uncontained failure of the stage 1 HPT rotor disk during a ground maintenance run of a CF6-80C2 engine. Again it said “the investigation of that failure had indicated that a crack initiated in the dovetail slot bottom aft edge. The root cause of the crack initiation remains unknown. However, cracks, burrs, or damage sustained in the dovetail slot bottom corner radii from improper handling and processing during new part manufacture and/or during maintenance were suspect for the September 2000 event.”
A previous AD, which became effective in June 2001, was also issued to mandate inspections of the CF6-80C2 stage 1 HPT rotor disc dovetail slot bottoms.
I don't know what the overhaul interval is for the CF6-80* series, but it's probably somewhere on GE AP's web site. As for whether the engine stays with the airframe, that's up to the operator - however, in the interests of quick turnaround, the answer is usually no. The engine is swapped out for a serviced one and the plane is sent back out while the engine is serviced/rebuilt and inspected.
Thanks
Most engines have containment and it goes all the way around. I am not familiar with this particular model but it is my understanding that all commercial aircraft engines are required to have full containment. But failures can and do happen. Most of them are contained.
ping
I guess that makes it easier to do the required visual inspection, but they may want to reduce the interval by a couple hours.
The AD applies to both 80C2 and 80A's (and now even A330 80E's) because both have had similar problems.
If I was the pilot/crew assigned to that flight (or a potential passenger), I would start drinking heavily. Right away.
Why was it snowing in California? ;-D
Like they grounded the Airbus fleet after a tail just sorta fell off?
Foam, foam on the range...
Luckily this happened on the ground with an empty plain... in the air, and you get a nice big death toll.
There were multiple Uncontained LPT failures on CF6-6 DC-10 in the 90's, but those don't matter. The public stopped wanting to fly on DC-10 back in 1979. THAT's What matters.
Your statements show that you really need to learn a lot when it comes to aviation. If you think a single engine failure is going to be the end of GE powered aircraft, you're very mistaken.
This incident is at least the THIRD uncontained failure of a CF6 HPT disk with two of those resulting in the plane being written off. Luckily both happened on the ground.
I said if one more of these happens in the air or 2 more on the ground, you can stick a fork in it. Sure GE won't let Dateline do a story on it, but there is always those hacks at 60 minutes.
No, but they are rapidly joining the DC-10 and MD-11 as "Freighter only" aircraft.
Given a choice between two airlines with one offering a 777 and the other an A300, the choice isn't going to be a hard one.
LOLOLOL
After working on Engine controls and Cabin pressure controllers for 20 years, the only way I get on a plane is after 3 or 4 belts.
The chances of one engine on a 747 damaging the other three are very slim but the odds are never zero.
The El Al crash in Amsterdam is an example. The #3 engine detached and hit the #4 engine causing it to also separate from the wing. The assymetrical thust plus damage to flight controls made it impossible to control.
As with every plane crash, it is never just one simple thing but a combination of things.
Would've been a better story if it happened in the air.
With a planeload full of nuns bringing 60+ infants to a nursury.
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