- Declare an emergency?
- Turn off the master switch?
My initial instict was to immediately turn off the master. However, I then thought that maybe you want to send a mayday as this is a serious problem, and this may be your only chance to communicate; once the master is off, you don't want to turn it on again...does this warrant a change in "Aviate, Navigate, Communicate"?
I discounted option 3, "Turn off the fuel valve", as just making a bad situation worse.
Master switch OFF Don't forget to fly the plane Extinguish the fire if possible, prevent spread Communicate with handheld radio or telephone
Severity of the problem might dictate an immediate off-airport landing.
I've had a few batteries short out on me but never a fire. Once a flap motor had been cannibalized and replaced with a clapped out one making flap operation five times slower and almost causing a fire. Luckily it hadn't.
If you have a handheld, then you can use that. Alternatively, if you need to stick it in a field/divert to a strip and land no radio, then do that first and then telephone the ATC unit you were speaking to.
Personally, speaking as someone who works with electrickery and electronic gubbery of various sorts, and having experienced electrical fires (thankfully on the test bench, not in the air ), including a power supply that blew up almost in my face sending two-foot flames shooting into the air (big capacitors y'see ), very good idea to kill the power straight away and extinguish the flames. Fire doesn't take long to spread at all.
Prioritise. Deal with the circumstance, then talk.
...this may well be your last chance to communicate.
Communicate what? The position where they can pick up your charred remains? What does "mayday" mean: "help me" in french. No one can help you when you have a fire in the cockpit except maybe your fire extinguisher. Talking to someone far away on the ground is really a waste of time when every second counts.
Talking to someone on the ground who could roll the fire trucks for your return, or come and collect you after you've crawled away from the field landing with a broken leg and burns, could be very valuable indeed.
I cant think of an emergency where the priority would not be deal with the emergency first and only when things are stable deal with letting the rest of the world know. I think most of us feel a mayday somehow makes everything comfortable but in reality there is very little those on the ground can do for us in most emergency situations.
- Declare an emergency?
- Turn off the master switch?
My initial instict was to immediately turn off the master.
Why turn off the master switch????
Aviate, Navigate, Communicate.
If you have them, don oxy mask and smoke goggles, then determine which system is on fire by isolating systems using the circuit breakers, I am assuming you are flying a light aircraft so there shouldn't be to many systems that would cause an electrical fire, if the aircraft is larger with more complex electrical systems then follow the initial memory items if any, then the checklist.
For example the type I operate has a 6 page checklist for this senario that eventually turns off all electrical systems except for standby instruments then re-instates systems to determine what is causing the fire.
Of course the senario out come is also determined by where you are at the time of the fire, over a remote area or nearby airports etc etc.
Last edited by Above The Clouds; 18th Jul 2012 at 11:21.
This is an interesting discussion, and I wish we had more of this sort of thing on PPRuNe.
Katamarino - good point about summoning help e.g. AFS, rescue etc., there again I would argue for Fuji's point that fire appliances etc. are not much use in the air. Letting someone know where you are is a good idea, however it is a question of priorities.
If there's a funny burning smell or slames start to lick up around the instrument panel any RT would be the last thing on my mind. My own priority would be to fly the aircraft, bring the situation under control and then get on the ground ASAP. Most likely one would be forced to divert into a field, or if the fire had been brought under control, the closest airfield, if it isn't too far away (i.e. a few minutes flight time). If there's been a fire you don't know what sort of damage may hav been done and so I'd want down ASAP. Plus I'd leave all electrics off just in case of re-ignition.
If flying an aircraft with electrically-operated flaps, I would argue it's still not a major issue. Most light aircraft will quite happily land flapless without a huge loss in landing performance. Larger, faster, more complex types perhaps but not C172s etc. A flapless C172 will still get into a field without flaps. If landing distance is really an issue then I'm sure that whacking into a hedge/fence fairly gently at the end of a forced landing is much more surviveable and hence desireable than being burnt to a crisp in mid-air whilst farting about trying to get the flaps down.
I remember an incident with a Cessna in Scotland a few years back - 2007 perhaps? The 60A CB for the alternator tripped, it was then reset and because of a short-circuit it welded the CB closed and caused a fire. They ended up doing a forced landing and everything was OK... anyone have the report for it?
A number of years ago I was flying as a FO on a Citation out of Biggin. We departed at night en route to Majorca and passing FL240 in the climb working London I noticed a shimmer around the Captains head which made me think my eyesight had gone funny. I could then smell burning. The smoke got worse and became very acrid and dense. We went through the normal procedures for smoke and London Control were brilliant giving us an emergency descent and vectors straight down through Gatwick in a direct line to Biggin. We had by then evacuated the smoke which was now diminishing and landed at Biggin to be met by the Fire engines who removed the petrified passengers who all though they were going to die. That smoke was so acrid it ruined all my pilot clothes which reeked. It is a horrible experience and the passengers could not believe how laid back and casual I was about the whole thing (Show for their benefit Obviously in a piston single if you have an oxygen mask put it on a cheap pair of swimming Goggles will keep eye watering smoke from your eyes. If not open the side window which will help to remove smoke as well as giving you access to fresh air. Even think of carrying a short piece of tube you can breathe through? Yes if you suspect an electrical fault switch off the electrics then switch off all the avionics bar one radio. Switch back on to make a call and appraise the situation. If the smoke continues to build with the master on and one radio go sans radio but ATC can be of help if for no other reason than giving you vectors. How else will you navigate with maybe diminished visibility and all the electrics off? But usually get on the ground as quick as possible and ATC can help there! BTW in our case it was a fan motor in the ducting system.
I think smoke/fire anywhere *inside* the aircraft is probably the worst emergency you'll ever have to deal with. I'd agree that the first thing to do with an obviously electrical one in a light aircraft is to turn everything off, removing the initial heat source, at least.
My thoughts then would be for an immediate forced landing/ditching, unless it was obvious the fire was completely out. You have so little time to do anything if the fire re-ignites or spreads out of view. Unless an airport was literally a minute or two away, it'd be field/road/lake/river, etc. Without 100% O2 you can be overcome in seconds - even then, you may not be able to see enough to do much other than crash.
As far as using the radio - well, that might be the source of the fire! Hopefully, someone might see you land and ring in with "I've just seen an aircraft go down in flames!" and be right for once...
This is something that should be aircraft specific. Consider a C152 with vents up high. Closing them only makes sure that you are going to breathe what's already in the cabin. In the case of an electrical fire it will be smoke which will then start to build up in the cabin. Why not open the vents and windows/ doors to get air flow through the cabin? Fire needs oxygen yes but it will surely get sufficient oxygen from the air flow through the cowl? I thought the point of turning ventilation off was to prevent smoke being recirculated to other parts of the aircraft cabin? This doesn't really apply to light aircraft. Hot or mixer air vents would be worth closing.
Would anybody consider turning the avionics switch off first to see if the smoke started to clear? Might be worth considering if you have electric flaps/ gear or what not and you do it as soon as you first smell or see any sign of smoke.
Electrical fires don't just start burning instantly, usually there is some warning from malfunctioning equipment so turning off this equipment and tripping the circuit breakers may well stop the problem.
If it is clear that the that the supply part of the system is part of the problem then first turn off the alternator before turning off the battery master switch.
In the UK a very quick Mayday call and a thirty seconds or so of 7700 on the transponder will get you no end of help, D&D will tell all the local airfields about the problem and then if your primary trace on the radar heads their way and you try and land you will get a green light from the tower along with all the fire trucks you will ever need if you head for a military airfield, all without you having to talk to them on the radio that you have turned off.
So going back to basics you need three things for a fire.........Fuel, oxygen & heat, if you remove any of these the fire will go out.
The aim should be to remove the heat first by turning off the electrical supply, once ths has been done it is likely the fire will start to subside as most of the contents of the aircraft are fire resistant and won't support combustion alone.
The most effective fire exigushing agent is BCF or HALON as the gas cools, displaces the oxygen and has a chemical reaction with the fire it's self so a quick burst of BFF/ Halon in the direction of the fire will have great effect but be sure to ventilate the area quickly as the reactond between the gas and the fire produces a toxic gas.
So the actions that I would recomend would be:- try to isolated the faulty equipment, if this is not done quickly turn towards a suitable landing place, make a Mayday call and set 7700 on the transponder, turn off the alternator, if no improvement . turn off the battery master switch, land at the nearest place that is safe to do so remembering that you may not have flaps (CESSNA) and may not have stall warning.
I would open all external-air vents, get a quick radio call in, maybe drop the landing gear and Flap 1, and then turn off power.
I always fly with a handheld GPS and a handheld radio anyway.
In a modern cockpit, there isn't much that can burn well in an electrical fire. Most likely you might get a short setting fire to some wiring.
What might burn quite fiercely is a LIPO battery in some handheld device. I carry one of those LIPO protector bags sold in model aeroplane shops, which are supposed to contain the flames (if not the smoke).