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View Full Version : UAL 777 lost an engine EWR to London


james737
19th Nov 2002, 14:02
Talked to a ual employee who does the ewr to london run and said they lost an engine last week and had to divert ! how many does that make for the 777 seems like its happening alot !

expedite_climb
19th Nov 2002, 14:18
Did they find it again is the question ?

Localiser Green
19th Nov 2002, 14:37
"the number 2 engine was later found on the right wing, after a brief search" :D

Herod
19th Nov 2002, 20:35
"To lose one engine is unfortunate; to lose two suggests carelessness" (Capt Oscar Wilde)

GreenArc
20th Nov 2002, 04:35
how many does that make for the 777 seems like its happening alot

The last figure I saw was one shutdown per 143,000 hours of operation for the UAL 777 fleet. Much better than the required 1 in 50,000 and nothing to be concerned with.

GreenArc

primreamer
20th Nov 2002, 21:01
Out of curiousity, can anyone confirm which engine type does UAL have fitted to its B777's?

Nigel PAX
20th Nov 2002, 21:51
> Out of curiousity, can anyone confirm which engine type
> does UAL have fitted to its B777's?

PW4000. UAL was the launch customer for the 777, with ETOPS 180 from day one with the PW4000.

yankeeclipper747
22nd Nov 2002, 06:09
A PW REP TOLD ME ONCE THAT SHOULD AN ENGINE (PW4000)THROW A FAN BLADE, IT WILL COME OFF THE WING IN 28 SECONDS. TAKING THE OUTBOARD PORTION OF THE WING WITH IT! THAT THOUGHT CERTAINLY SENDS A CHILL DOWN MY JET A!

The Trappist
22nd Nov 2002, 06:54
From the guys at the Orval Bar…
Emirates have lost their 180 minutes ETOPS down to 120 minutes.
This due to the number of engine failures on the 777 fleet. Oh, and they’re using Rolls Royce power plants.

expedite_climb
22nd Nov 2002, 06:57
Yankee clipper,

Just how would it do that then ?

i) The engine is not on the outboard section of wing
ii) The engine is mounted forward of the wing, and as the wing is swept back the outboard wing is even more further back.
iii) The engine case / cowl is designed to prevent a catastrophic destruction of the engine, and if this were still to happen
iv) The wing immediately above and behind the engine (where engine parts may hit) is a 'dry box' meaning it is designed with the engine failure in mind, and there is no fuel in that area. One would assume it may be reinforced then ?

Don't believe everything you are told.

lomapaseo
22nd Nov 2002, 11:33
>A PW REP TOLD ME ONCE THAT SHOULD AN ENGINE (PW4000)THROW A FAN BLADE, IT WILL COME OFF THE WING IN 28 SECONDS. TAKING THE OUTBOARD PORTION OF THE WING WITH IT! THAT THOUGHT CERTAINLY SENDS A CHILL DOWN MY JET A!<

Obviously you misunderstood.

Never have I heard such a story in all my bar elbowing with P&W, GE and RR reps. The only concern has ever been is if the fan disk itself only partially fails and throws several blades along with a piece of itself. It's about as bad as thowing two blades from a four bladed prop.

Never-the-less, the wing is protected from falling off by being able to sustain more load then the engine mounts.

Old Aero Guy
22nd Nov 2002, 18:55
YankeeClipper747,

You must have been speaking to a very junior PW guy.

To be certified, the engine must be capable of containing the fragments of a lost fan blade. In addition, it must shut down safely and present no further hazard to the airplane.

As far as the wing is concerned, the fuse pins attaching the engine to the wing will fail prior to wing failure for a wide variety of extremely rare engine failures.

Interestingly enough, some of the highest loads would be imposed if a bearing failure were to stop the engine suddenly at TO power.

Fusing the engine allows it to safely separate, leaving the wing intact.

headwind
22nd Nov 2002, 19:43
Old Aero Guy

I can easily believe what you say. Working at a research centre, the bearings of a turbo pump weighing about 50kg suddenly failed and the pump jammed at full speed (20 000 rpm). The thud was felt in the entire 3-storey building as the pump separated neatly from its mounting to the concrete floor. Fortunately the pump was also attached to a 2000 kg piece of equipment which absorbed most of the shock. Having seen cross sections of jet engines and such pumps, they look similar except one is injected with JET A1 and the other with current. It would be nice to know how much the rotating parts of a PW4000 weigh....

-hw

411A
22nd Nov 2002, 19:46
......'course, if Boeing fuse pins are looked at really carefully, the AD/SB list is rather ah....long.

Opps...good gosh Captn, the engine fell clean off...
And from the cabin...hey Rastas, it's done gone!:eek:

lomapaseo
22nd Nov 2002, 23:59
> Interestingly enough, some of the highest loads would be imposed if a bearing failure were to stop the engine suddenly at TO power. <

Old One

I hate to get picky because you are generally spot on. But what the heck, you're always willing to learn.

The largest rotor seizure rates recorded occur during the blade off events in a test cell and even in that event their seizure rates are no greater than about 2 X the Ni limit per sec.

Example for a big fan machine this would be a bout 2 X 2500 RPM per sec for a decel rate. The mounts are sized for about twice that rate again for just plain seizure, which if it were ever to occur would plastically twist the drive shaft somewhat. All in all nobody has ever come close to developing pure seizure loads of this maginitude in service for anything bigger than a JT8D except in ground impacts.

On-the-other-hand, if you combine the normal seizure loads with a large unbalance greater than a single fan blade off, you may develop bending moments in conjunction with torque moments that just might break a mount. Thus my comment about a multiple blade loss (with the disk being the fracture point) being tne real risk.

By-the-way, the bearing system can not sustain massive seizure loads so bearing seizures are not a problem. In addition the engine stators can not sustain a massive seizure and will simply start rotating themselves or fracturing completely long before you can shear the mounts in pure seizure torque.

Old Aero Guy
23rd Nov 2002, 01:31
lomapaseo,

No argument here.

Note the Aero in the name.

In this area all I know is what the Propulsion and Stress guys have told me.


411A,

Usually because they release too soon rather than too late.

autopilot_99
29th Nov 2002, 00:48
The Trappist
Emirates did not lose 180minutes ETOP but management reduced it to 120. In fact currently, they do not need it !:p