A 330 FUEL ENG 1(2) FEEDLlNE BURST

[JABBARA]

Hi Gents,

A 330 ECAM FUEL ENG 1(2) FEEDLlNE BURST

I consider this ECAM displays in the case of rupture of a Fuel Pipe to engine.

If this is correct, how it can be deteceted?
The first method which coming to my mind, is an abnormal Fuel Flow.

Any idea please

Thanks.

[safelife]

It is the so-called Air Transat failure.
Normally it goes unnoticed, the crew will transfer the remaining fuel from the unaffected side into the fast depleting side, and eventually the engines will flame out due to fuel starvation.
The crew will then continue as a glider, and make a landing in Lajes.

[JABBARA]

I guess in AirTransat case, this ECAM was not there.

After this incident, this ECAM is invented.

[Meikleour]

JABBARA: IIRC the Airtransatt crew referred to the FUEL IMBALANCE and the FUEL LEAK/LOSS checklists in the QRH but chose to disbelieve what their fuel gauges were telling them on the ECAM. They opened the crossfeed valve despite valid indications of a fuel leak. The rest is history.

[aguadalte]

The procedure shown in FCOM PRO-ABN-28 Fuel, starts with the assumption of an ENG FAIL.

Otherwise there are two other procedures available: FUEL L (R) WING PUMPS LO PR (THE FAILURE IS NOT DUE TO AN ENGINE FEED LINE RUPTURE), or the FUEL L (R) WING PUMPS LO PR (THE FAILURE IS DUE TO AN ENG FEED LINE RUPTURE).
(My bold)
This is a very serious situation as the pilots must apply their best judgment when analyzing the failure.
The best way to detect a fuel leak is to keep constant record of the Fuel Used vs AFOB. The sum of those two numbers has to be consistent with the actual FOB at departure.
Another way to keep a closer look at the Fuel System is to keep in mind the Fuel Over Destination figures. To get consistent numbers on FOD, winds and expected LVL Changes have to be inserted on the FMGEC no later than a couple of minutes after the TOC.
When we notice more than 300kg of difference on our estimated FOD it is normally because there is a TRIM AFT/FWRD or OUT TK FUEL XFR going on..after completion of the procedure we'll get the right number again. (Fuel being transferred - actually flowing in the lines - is not measured by FCMC).
I think the best way to manage the FUEL SYS is to be aware of what's going on.

[JABBARA]

Thanks for answers,

Probabaly, because of my English, I couldn`t ask my question properly.

What I want to ask: "How the Fuel Line Rupture is deteceted by the system itself", not by Pilot.

I mean, which kind of sensors may trigger this ECAM ?:
# Excessive fuel flow measured by flowmeter, FADEC?
# Fuel flooding, so wetting the sensors around the pipe or within the compartment where pipe is passing through?
# or another method...?

Thanks

[Meikleour]

I think it is triggered by the fuel imbalance achieved between the left and right tanks all other parameters being equal. Can't remember the imbalance figure to trigger the ECAM - it's been too long for me!

[Nepotisim]

The aircraft knows how much fuel is being used by the aircraft by from both engines fuel flow transmitters.
The aircraft also knows how much fuel is in the fuel tanks and what rate it is dropping through the fuel quantity indication system.

It will be the difference between these two parameters that will trigger the warning.

ie: If the L/H tank is dropping at 500 kgs an hour and the engine is using 250 kgs an hour then that difference is going somewhere.

There are no sensors around the pipes in the strut or on the engine.

[JABBARA]

Thank you Nepo, and all.

Nepo, your explanation makes sense. You are engineer, so you are sure there is no sensor around the pipe.

In this case another question comes my mind. FCOM ECAM states :

FUEL ENG 1(2) FEEDLINE BURST

LAND ASAP (AMBER)
ENG 1(2) FAIL
,,,,,,,,Then the other steps on the ECAM

So, ENG FAIL will not necessarily occur with this ECAM, because as per your explanation, some part of the fuel is still fed to engine.

And, in AirTransat incident, as far as I understand from NAT GEO Air Crash Invest video, pipe completely ripped off, however engine was still running. So is there more than one Engine Fuel Feed line to keep engine running?

Thanks you if you can answer.

[noughtsnones]

I haven't seen the NAT GEO Air Crash Invest video (showing or not) the fuel pipe completely ripped off, but this view is seriously at odds with the photographs in section 1.6.3 of the GPIAA final report (22 / ACCID /GPIAA / 2001 (http://www.skybrary.aero/bookshelf/books/538.pdf)). The fracture does not extend all round the pipe.