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divinehover
6th Nov 2006, 09:48
The Airbus A340-600 FCOM 1.28.10 (Fuel System Description) talks about Rotor Burst. Could someone briefly explain what this is please.

Here is an extact from the FCOM

ROTOR BURST TRANSFERS
The FCMC enters the rotor burst mode, if both split valves are selected and one engine LP valve is shut. If an inboard engine rotor burst occurs, all automatic transfers directed to the inner tanks are into inner tanks 1 and 4 only.
If an outboard engine rotor burst occurs, all automatic transfers, directed to the inner tanks, are into inner tanks 2 and 3 only.

N1 Vibes
18th Nov 2006, 09:00
Hi Divinehover

you don't want to ever see one of these. This is the same failure mode as the Sioux City DC10 engine failure (see http://www.airdisaster.com/special/special-ua232.shtml). Imagine thas fan disc in the engine is about 300lb in weight, turning at up to about 2,000rpm and it decides it doesn't want to be round anymore, rather it would like to disintegrate into a number of smaller not so round pieces and see what life is like outside the confines of the engine. It would probably find it's way up into the pylon/wing and make a not so pretty mess of the fuel system. Hence the FCOM note.

Happy flying!:uhoh:

barit1
20th Nov 2006, 01:53
Not pretty. (http://aviation-safety.net/database/dblist.php?Event=ACEU) Lots of things get ruptured - hoses, tanks, fuselage skin...

But it's so rare an occurrance, I have never seen a system designed to mitigate its effects. Is the A346 the first FCOM to include such language? :confused:

lomapaseo
20th Nov 2006, 13:14
Not pretty. (http://aviation-safety.net/database/dblist.php?Event=ACEU) Lots of things get ruptured - hoses, tanks, fuselage skin...
But it's so rare an occurrance, I have never seen a system designed to mitigate its effects. Is the A346 the first FCOM to include such language? :confused:


Interesting listing, even includes a piston engine jug failure

barit1
20th Nov 2006, 23:48
Interesting listing, even includes a piston engine jug failure

Now that you mention it, that listing omits this (http://www.ntsb.gov/ntsb/brief.asp?ev_id=40041&key=0) accident, wherein a failed cylinder precipitated a cowl unlatch, with such drag & loss of lift in its wake that it could not maintain altitude OEI. :sad:

idg
22nd Nov 2006, 22:31
IMHO
Modern engines are certified with fan blade off tests, therefore I would contend that damage is much more likely from turbine blade release which, since they're very hot, would pose a very strong risk to tank damage and thus fire. In addition (esp on a twin) the turbine is ususally in line with the tank...not the fan.

Two incidents that spring to mind are Manchester and the recent AA 767 that let go during a ground run causing a hull write off. Plenty of other 'engine failures' to choose from.

So perhaps not so unlikely!

What I'm curious to know is how the FCMC 'senses' that it has a 'rotor burst' situation?

barit1
23rd Nov 2006, 01:15
... I would contend that damage is much more likely from turbine blade release which, since they're very hot, would pose a very strong risk to tank damage and thus fire. In addition (esp on a twin) the turbine is ususally in line with the tank...not the fan.
Two incidents that spring to mind are Manchester and the recent AA 767 that let go during a ground run causing a hull write off...


Neither Manchester nor LAX AA767 were turbine blade failures, which are relatively innocuous (contained failure) under certification rules.

Manchester was a combustor case failure, resulting from a burner can or nozzle failure, with a burnthrough of the 200 psi pressure vessel.

The LAX failure was a HPT disk failure - disk segments of over 100 lb. released to cannonball their way through primary structure. Potentially the worst failure mode of all, and one that turbine designers work VERY hard to avoid. (Even so, I'm not so sure the 767 hull was a writeoff - but I could be wrong.)



What I'm curious to know is how the FCMC 'senses' that it has a 'rotor burst' situation?

An excellent question!

lomapaseo
23rd Nov 2006, 15:31
I'll have tyo admit here that I really don't fully understand the jargon.

I surmised that by rotor burst what they were protecting against was any uncontained failure (of any engine part) that might have compromised the integrity of a fuel tank.

That if that were to be presumed that to avoid the Air Transat situation that certain protocols of fuel management would be necessary.

all of the above of course is subject to my own personal confusion about the preceding discussion :)

Nelli
23rd Nov 2006, 21:21
idg and barit1


ROTOR BURST TRANSFERSThe FCMC enters the rotor burst mode, if both split valves are selected and one engine LP valve is shut.
I think this is how the FCMC "senses" the rotor burst:confused:

jettison valve
25th Nov 2006, 18:20
divinehover,

What does the FCOM say about the wiring that runs along the trim pipe (and maybe also along the APU line on the A3456)?
I would assume that a discontinuity of this wiring is treated by the FCMCs as a strong indication towards a rotor burst as well...?!:confused:

Cheers,
J.V.