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-   -   Uncontrollable Engine Fires (https://www.pprune.org/tech-log/293446-uncontrollable-engine-fires.html)

'holic 3rd Oct 2007 22:47

G'day all,

Starburst, you are absolutely correct in that the landing distance of 3000m I quoted was factored. You are also correct that the main thrust of my original question was more to do with returning to land in a time critical situation when it is imperative that you get the aircraft on the ground ASAP.

Having said that, there's been some excellent information posted on engine fires. At the risk of starting a thread drift to my own question, I was wondering how long you could leave an engine fire without carrying out the recall actions before the fire spread and/or a catastrophic structural failure.

To try and put this in a practical context, say you are conducting a Low Vis approach and have a fire warning. Obviously, you would declare a Mayday, continue the approach and autoland. If the fire warning occurred at 2000' you would have enough time to carry out the recall actions. If it occurred at 50', you wouldn't. What height would you use as a cutoff between actioning recall items or not actioning them?

Starbear 4th Oct 2007 09:19

hello again 'holic

before I offer another tuppence worth, I would just caution against trying to have specific answers to all possible problems because that's just not possible. I don't think that is what you are doing here and are justt exploring some options but be careful nonetheless.

That said, as far as a cut-off height goes for recall items, many companies stipulate no actions below 500 ft AGL except for cancelling noises; raising gear; applying full thrust (if required) and commencing emergency turn if required. So in other words no drills (recall or otherwise) below this height, not even analysing the fault.

Most of that certainly implies a take-off scenario but in terms of drills can easily and often is applied to the approach situation as well BUT it will depend upon each situation because the most ipmortant consideration always is "Fly the aircraft". Easily said but often easily forgotten and especially by the PNF! The PNF's job in these situations is crucial and they must monitor PF's flying and ensure a/c is correctly configured on the correct flight path before even considering any other actions including ATC. Only when you consider it safe to action recall items without compromising flight path safety should you request them. Even 1,000 ft AGL (for example) could be considered too low in some circumstances whilst just above 500 ft may be acceptable in others. The danger comes from a breakdown in proper monitoring of those recall items and you just cannot afford to get it wrong close to the ground. You could consider briefing your colleague to action recall items once on ground at a safe speed BUT even that needs care. Whatever you decide, a Mayday call even on short finals will get help speeding towards you should it be required.

Also worth noting than the vast majority of Engine Fire Warnings are generated by hot gas leaks and often disappear when thrust is reduced towards idle and that could be considered without shutting down the engine at low heights and avoids reconfiguring a/c but will also inscrease workload somewhat with asymmetry and speed control. (much less of a problem cat2/3, just add some thrust)

Sorry, but that all sound a bit like preaching on re-read but I do believe its important and worthy of discussion.

411A 4th Oct 2007 15:11

With engine fires especially, it would seem that the 'Comet syndrome' is alive and well with some pilots.
'OMG, we have to do something now'...when in actual fact, engine fires, although sometimes serious, often to not require immediate action...such as on short final at low altitudes, or indeed at very low altitudes after takeoff.

Haste makes waste, is many times true.


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