Engine Fire???

[AeroTech]

Hi,

In case of engine fire, the engine is shutoff and the fire extinguisher is used.
Can the pilot restart and operate the failed engine if there a need of this engine: let's say the second engine in twinjet failed also (so shutoff) during an extended diversion and it is no longer able to deliver thrust, hydraulic & electric power

Why engine oil is not shutoff in case of engine fire as fuel, hydraulic, air, electricity? is engine oil not flammable?

Thank you.
Best regards.

[Trash Hauler]

Would you restart an engine that has been shutdown due fire? How bad is your day that you would have to consider this as an option. The premise of ETOPS is that statistically the second engine will not have an occurrence that results in loss of thrust, therefore this consideration should not be required. However the Air Transat A330 incident shows that when humans are involved statistics do not acount for everything.

Oil supply is required for lubrication as the fan and core will 'windmill' from the airflow.

[Old Smokey]

I would never contemplate re-starting an engine after a fire warning in except the most dire of emergencys. I would consider failure of the remaining engine/s a dire emergency, but even then, hoping against hope that the original fire warning was a false alarm. And if the original fire warning was genuine, it WILL inevitabely catch fire again, and you're now in a much bigger pool of excreta, because you've already blown your extinguishers.

What Trash Hauler said about oil supply is true, but frankly, from the performance aspect, you'd be better off if the failed engine quietly siezed, because a siezed engine has less drag than a windmilling one.

Regards,

Old Smokey

[lomapaseo]

..., but frankly, from the performance aspect, you'd be better off if the failed engine quietly siezed, because a siezed engine has less drag than a windmilling one.

Regards,

Old Smokey

Ah ha finally somebody listens :)

[Trash Hauler]

I suspect the reason for continued oil supply is the risk of a catastrophic seizure and the resulting tortional load to the pylon. I think the engine coming off the wing could spoil your day.

[Old Smokey]

I find it difficult to conceive of a catastrophic seizure with a windmilling engine. The only resistant torque would be as a result of it's existing low rotation speed, unassisted by any driving force from combustion. Loss of oil pressure at a much higher 'driven' rotation speed would be a different matter altogether.

With the engine that I currently operate (RR Trent), the recommendation following aborted start due to no oil pressure is to still carry out a motoring cycle.

Regards,

Old Smokey

[guclu]

because a siezed engine has less drag than a windmilling one.

Just what I want to clarify Old Smokey,

I know this is true for Propeller airplane but according to A340 FCOM a windmilling engine has less drag than a rotor locked case.

From the FCOM for ferry flight:

The performance data are provided for the rotor locked case. Fuel consumption for the windmilling case is about 3% lower.


Best Regards,

Guclu

[Escape_Slide]

An engine fire and shut down would require the aircraft immediately divert to the nearest suitable alternate.

For and A320 say, subject to winds, a rough rule of thumb for a 260Kt descent, is to take the altitude of the aircraft in feet, divide by 1000 and multiply by 3 to give roughly the distance to land in Nm.

e.g. 25,000 feet x 3/1000 = 75 Nm or roughly 15 mins

For a 120 min ETOPS this means the second engine must keep the aircraft at 25,000 feet for another 105 mins (bleed reduction)

Depending on when the second engine failure occurs, a non suitable landing field or ditching might be contemplated.

With no suitable place to land in sight, one might be tempted to weigh up the risks of restarting on the basis the fire warning that lead to the shutdown was false.

Of course, a fire can destroy the aircraft and its occupants if it cannot be contained.

[barit1]

But what if you found yourself in this situation?

8 January 1989; British Midland Airways 737-400; near East Midlands Airport, UK: A fan blade failure at top of climb damaged one engine and the crew mistakenly performed a precautionary engine shutdown on the wrong engine. The damaged engine lost power shortly before landing and the flight crew was unable to restart the good engine prior to striking the ground. 47 of the 118 passengers were killed.

If you had pulled the fire handle on the wrong engine, there would be no reason NOT to restart it!

[Old Smokey]

What you describe barit1, is a crew error, and a REVERSABLE crew error at that.

Without any access to the report, I am of the belief that, right up to the last the crew were unaware of their error. Had they been aware, or any of the rest of us been aware in the same predicament, none would have had any hesitation in re-starting the inadvertantly shut-down 'good' engine. That's not a re-start of an engine that's suffered a fire / fire warning, but the correction of an error.

If we go all the way back to the original post, and insert the Kegworth circumstances to the scenario, it illustrates well the inadvisability of the deliberate continued operation of an engine which has suffered a fire.

Regards,

Old Smokey

[john_tullamarine]

Kegworth Accident Report (http://www.aaib.dft.gov.uk/cms_resources/dft_avsafety_pdf_502831.pdf)

... and, of course, there but for the Grace of God .....

[barit1]

Two quick items:

At Kegworth, the pressure vessel was ruptured, thus thrust went to zero (almost) instantly. Performing the shutdown checklist would have had no effect on thrust. Further, it was the secondary damage (fuel spilled) that caused the disaster.

Secondarily: Is there any case in which the fire handle should be pulled without a fire indication? It's been a long time since I had a FCOM or QRH handy - maybe someone can fill this blank for me.

[Piltdown Man]

And let us not forget than in many aircraft, you can't "Undo" the Fire Handle. It's a one-way lever. Therefore, the option of restarting is not available.

[lomapaseo]

Two quick items:

At Kegworth, the pressure vessel was ruptured, thus thrust went to zero (almost) instantly. Performing the shutdown checklist would have had no effect on thrust. Further, it was the secondary damage (fuel spilled) that caused the disaster.

Secondarily: Is there any case in which the fire handle should be pulled without a fire indication? It's been a long time since I had a FCOM or QRH handy - maybe someone can fill this blank for me.

I guess I just don't understand where you are coming from in the comment about thrust going to zero.

What pressure vessel was punctured.?

If it is in the fan or non-core pressure part of the engine then it only has a small effect on the rest of the engine, unless of course something else is wrong.

As for your last question. I asked my instructor the same and he replied that for a severe engine failure the assumption is that their could be a fuel leak and instead of waiting for a potential ignition source, pull the shutoff via the fire handles after you have cleaned up the aircraft.

[Techman]

As mentioned, you would pull the fire handle in case of severe engine damage, and also in case of fuel leak from the engine.

[Caudillo]

... and, of course, there but for the Grace of God .....

Have to say thanks for posting this, it's a pretty hefty report as you'd expect - and aside from many of the set-piece lessons that hopefully most of us have been taught as a result of this, there's a great deal of food for thought throughout.

One thing that struck me, thinking about that roll to the left they initially experienced, was how that big clue that we're all taught from the moment we start handling multi-engined aircraft wasn't recognised.

But that is easy to say here I know. It always amazes me how even the tiny distance from say sitting and observing on a jumpseat to moving to one of the two seats at the front to interact with the aircraft changes absolutely everything.

On a lighter note, perhaps this same phenomenon explains a great deal with sports referees?

The report is definitely recommended reading!

[NigelOnDraft]

Secondarily: Is there any case in which the fire handle should be pulled without a fire indication? Yes - if the engine won't stop after flight in the normal way, and you want to go home :)

[barit1]

I mistakenly wrote:

At Kegworth, the pressure vessel was ruptured, thus thrust went to zero (almost) instantly.

Mea culpa. I intended to refer to the Manchester 737-200 accident (22 Aug 1985) in which the combustor case failed early in the TO roll, due to burner can torching. The fire warning indication was delayed, and the thrust loss led the crew to suspect a blown tire on that side, so they rejected TO. Unfortunately the spilled fuel on the upwind side of the fuselage fed a disastrous fire.

[Swedish Steve]

Is there any case in which the fire handle should be pulled without a fire indication?
It was standard practice on the GF Tristar, that with an u/s APU you shut down Nbr 3 engine last by pulling the fire handle. The engineer then checked that the HPSOV was closed and reset the fire handle. The engine would run for over a minute before shutting down. The thinking was that when shutting down engines you needed a pneumatic source (APU) to motor the engine over if there was a tailpipe fire. With the APU Inop then shutting the spar valve meant there was no fuel in the engine to cause a fire.

[AeroTech]

Hi,

Thank you for posts.
According to many posts, it seems there are no regulations (FAR's, JAR's) and procedures (aircraft manufacturers & companies) regarding the restart of shutoff engine after fire if there is a reel need if this engine. May be it is obvious for them since there both extinguisher bottles are discharged (so no need for regulations..)? or is it up to the pilot to decide?
-Can we restart an engine that have been shutoff for another raison than fire? (of course if there a reel need of this failed engine).

I know an windmilling engine need lubrication, but I am still wondering if the oil can cause damage fo the engine during fire. Even tough the oil is synthetic (I don't know its characteristics: flash point...), high temperature may ignite oil vapor. Hydraulic fluid (Skydrol) is fire resistant, but yet it is shutoff in case of engine fire. May be fire detectors are not totally reliable (which seems true) so we don't want to loss an engine by shutting off oil? may be there is another raison?

Originally posted by Piltdown Man
And let us not forget than in many aircraft, you can't "Undo" the Fire Handle. It's a one-way lever. Therefore, the option of restarting is not available.
Can you please mention some examples?

Originally posted by Techman
As mentioned, you would pull the fire handle in case of severe engine damage, and also in case of fuel leak from the engine.
may be in such case we can just move the engine start levers to cutoff (both spar valve and HPSOV are closed), and we can still get a hydraulic power (limited) from the windmilling engine if not seized of course.

Thank you.
Best regards