You have an electrical fire in the cockpit...

[Discorde]

For the PA28 (and perhaps similar types)

[abgd]

Are you talking about putting items such as laptops into the LiPo bag from the beginning to the end of the flight, Peter?

That would make sense to me, but from my experience of LiPo fires, once they're started you're probably not going to be able to get anywhere near the device safely, or pick it up.

If you could, I would have thought that throwing the thing out of the door would be both the easier and safer option, at least if you were over a reasonably rural part of the UK. Over central London or a tinder-dry forest there may be other considerations.

[A and C]

Discorde

Not a very good fire drill ! A panic turning off of the master switch before any investigation has taken place followed by the discharge of the extinguisher.

Oh , and then turn the whole lot back on for the distress call and to restart the fire !..........I hope the extinguisher is big enough to put out the fire twice?


Who publishes this stuff ?

[peterh337]

abgd

If I had a laptop actually on fire, the plan would be

- engage autopilot for altitude hold (AP ALT)
- close the throttle
- rudder trim fully right
- at onset of stall buffet open door and chuck laptop out
- recover as normal

Otherwise try to remove the (hopefully only smoking at that stage) battery and put it in the fireproof bag.

[Squawk_code]

Folks,

Some good info and advice here...

Flight Training: Aircraft Fires

Cheers,

Squawk.

[abgd]

I've had a LiPo flameball in the relative safety of my own home, and all I managed to do was to get out of the kitchen. I might have dared fling it out of the window if I'd been wearing Nomex but it all happened pretty fast. This video is pretty reminiscent of what I experienced. You get a puff of smoke, accompanied by the sound of venting gas, then the chain reaction starts very quickly:

[peterh337]

I don't disagree with any of this, but the fact is that airlines do allow laptops to be used during flight, and one assumes they have done some sort of risk analysis, and most laptops have LIPO batteries.

I suspect that the risk of this is very low with any normal consumer product. Model plane batteries have been known to go incandescent more often but I think that is for a number of reasons

- they are charged at very high rates (a lot more than 1C in some cases)
- they are discharged at huge rates - 100A is not unusual
- they get a lot of physical hammering - when a model crashes, it could be 100s of Gs, and I know that often the battery is totally smashed, but if it is still "apparently" working the owner is not going to chuck it away because it probably cost £100
- I don't get the impression that model plane bits are of particularly good quality - they are constantly packing up...

To minimise the risk, I also tend to not charge batteries during flight. I tend to keep the device(s) charged so even though the supply is connected, the internal charger turns off ASAP.

[Discorde]

Not a very good fire drill ! A panic turning off of the master switch before any investigation has taken place followed by the discharge of the extinguisher.

Oh , and then turn the whole lot back on for the distress call and to restart the fire !..........I hope the extinguisher is big enough to put out the fire twice?


Who publishes this stuff ?

In the PA28, switching off the master switch would not immediately compromise aircraft controllability or safety. In instrument conditions suction gyros would remain functional and pilots flying at night would most likely carry a torch for standby illumination of the panel. If the system causing the problem can be isolated then the option of switching the master switch back on is restored.

As in all emergency situations, there will be judgement calls to be made following risk assessment. For example, is the fire severe enough to warrant discharge of the extinguisher, which will bring visibility and breathing problems (as will the combustion products of a fire which is not extinguished). The benefit of a distress call is that the emergency services will be alerted. You may well need them later, particularly if your landing is away from an airfield.

A final point is that checklists can never replace sound judgement. They are designed to assist you in dealing with most normal and non-normal situations. Occasions may arise where you need to deviate from published checklist procedures because circumstances demand it.

[Noah Zark.]

Further to a point mentioned a couple of times already in this thread, discharging a fire extinguisher on board an aircraft.
Obviously if a fire occurs, one of the things a person might do is to set off an extinguisher, but if it a powder-type device, and especially if it is a non-controllable (i.e. a one-shot empties all at once) and especially in an enclosed light aircraft (PA28, 152, 172, etc.) the chances are that you will almost immediately become incapacitated by the powder. It smothers everything, people included, and is harmful to inhale.
I am not 'up' on rules and regs. regarding fire extinguishers on board light aircraft, perhaps powder types are discouraged, or even banned, I don't know. But I have seen them in situ in various light aircraft I have seen fairly recently.

[BigEndBob]

I had a short circuit in a Truimph TR7 car, a few wisps of grey smoke form behind the dashboard. I jumped out, grabbed a spanner i had in the boot and disconnected the battery. All that took was about 5-7 seconds.
The cabin by that time was filled with a grey acrid smoke, one whiff of which i caught as i opened the door took my breath away. If i where in that cabin i would be dead within a few seconds.

I had a Cessna ldg light switch short out, known for doing that, again a few wisps of cigarette type smoke, i gave very quick call to ATC and switched off the master switch and landed asap.
I wouldn't trust an aircraft fire extinguisher, used a dry powder twice to put fires out, useless. Just watch those motor racing crash videos.

[Big Pistons Forever]

I have to ask. Does anybody actually look at the emergency procedures in their POH? All Piper and Cessna POH's have a section in the emergency procedures manual that deals with cabin fires and all these procedures start with turning the master off.

To those who advocate other courses of action I am curious to know what makes you think you know better then the factory engineering test pilots that wrote the emergency procedures?

I would also add that both manufacturers and regulators have rethought the circuit breaker resetting procedures. The now virtually universal consensus is to never reset a circuit breaker unless the emergency checklist specifically calls for it and to never reset a circuit breaker twice.

For light aircraft I teach to never reset a circuit breaker in flight unless the electrical service it is protecting is essential for continued safe flight.

[abgd]

There are a few different types of LiPo batteries, and my impression is that some of the newer ones are much less likely to spontaneously combust than older ones - even with the trials of r/c use. I recently tried puncturing the battery from a dead PicoZ type helicopter (cheap £10 micro-helicopter) and... Nothing happened. I also had a small 850 mAh 3s battery where one cell died and the others got way overcharged. I disposed of it safely in a glass of salty water, but was pleasantly surprised that it hadn't already blown up - a few years back there would probably have been fireworks.

I'm not sure quite how popular LiPo batteries are in laptops - a while since I looked into them and at that time Lithium Ion types or LiFe were more popular and these are much more difficult to provoke.

Although LiPo fires are quite fierce, they are brief and probably don't release much more energy than an exploding cigarette-lighter - even for quite a large battery. I wouldn't be surprised if it were possible to deal with one burning up in the passenger compartment, but the cockpit (as in a light aircraft) might be another matter.

On the other hand, an UPS air-freighter may have been brought down by a LiPo fire in the hold, and MIT were recently fined for failing to label a packet of Lithium batteries that were sent by air-freight.

The other thing to watch out for is temperature changes. The voltage the batteries produce varies with temperature, but the critical voltage at which they spontaneously combust stays relatively constant, so if you charge them in the cold then bring them inside, this can send them off. At least two people have come to grief recently from the helifreak forum. One person lost his SUV a year or two back, and another lost his house. Thankfully his family and pug dog survived.

My helicopters mostly run on A123 batteries - LiPo are fine if you've got a garage with a concrete floor, or a detached shed. But when I lived in a flat they gave me the heebie-jeebies.

[Katamarino]

The POH does indeed specify Master Off as the first action. It would be naiive to unquestioningly assume this is the best course of action in every imaginable scenario.

[The500man]

POH checklists tend to be a bit lacking in general, and no one uses the emergency one's during an emergency. It's much more likely most pilots will use a generic memory checklist.

It would be silly to assume the aircraft manufacturer checklists are the be-all and end-all and I say that because if you look at a POH and then look at, for example, the engine manufacturers manual they often are somewhat different about engine handling. So who knows best? The aircraft manufacturer or the engine manufacturer?

[Pace]

Timeline: Swissair 111 crash investigation - Canada - CBC News

There was a very good film made of the Swissair MD11 crash where the Captain was an official procedures man! The First officer made all the right judgments but the Captain insisted on going by the book and left the final approach to go out to sea to dump fuel with awful consequences.
Every situation is different but priority with smoke in the cockpit has to be to land as quickly as possible.
As stated I have been on a flight with an electrical fire and until you have experienced just how dense and acrid the smoke can be it is hard to appreciate the reality of such a situation.
In a light GA first port of call has to be to isolate the source of the fire so the master switch has to be the first point of call in an electrical fire.
I would probably then manually shut everything down apart from one radio and then go back on with the master and monitor the situation.
ATC were a massive help in our night fire basically because they reduced the work load by giving us direct vectors and clearing airspace for an uninterupted descent so if its possible to keep radio contact all the better even if the radio is on for short periods of time.

Pace

[FlyingLapinou]

There was a very good film made of the Swissair MD11 crash where the Captain was an official procedures man! The First officer made all the right judgments but the Captain insisted on going by the book and left the final approach to go out to sea to dump fuel with awful consequences.
Every situation is different but priority with smoke in the cockpit has to be to land as quickly as possible.

I've posted the link to the film below.

Swissair Flight 111

[Pace]

Thanks for the link its a must watch as it highlights a number of points.
One in this instance is that every situation is different and while going by the book is correct in most circumstances there are times when you should chuck that away and go with your instincts.
The first officer was sensing the right decisions the Captain was a by the book man but whatever a sad result!

Pace

[172driver]

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.

Exactly. I may add that in the UK you'll never land far from someone (some remote parts of Scotland excepted), but if you fly in places without human presence, letting ATC know what's up is, IHMO a very good idea. You don't even have to travel very far for that, parts of central France or Spain are pretty empty.

If possible, I would therefore do a quick Mayday, hit the squawk ident button and then shut everything off PDQ.

[Big Pistons Forever]

Originally Posted by The500man

POH checklists tend to be a bit lacking in general, and no one uses the emergency one's during an emergency.

I completely disagree with this statement. All the typical later model aircraft you will find at flight schools and clubs have a pretty comprehensive set of procedures for the likely emergencies and they all specifically cover the cabin fire emergency.

The outfit where I do some part time instructing flies C 172P's. The POH for this aircraft has emergency procedures which follow the industry convention of showing those items which are meant to be done by memory in bold face type and the remainder in plain type. I require my students to know all of the bold items by memory and quiz them regularly to insure they know them. There are not a lot of procedures to memorize so I do not consider this an onerous task.

When the bad thing happens and the pressure is on, this is not the time to start making things up, you have to have the initial procedures down cold. The POH emergency procedures are not perfect and will not fit every problem but I firmly believe every emergency should start with the publish procedure and deviations from it should only occur when its actions are not making the situation better.

The bottom line is a cabin fire in a light aircraft is IMO the worst possible emergency. They are almost invariably caused by electrical problems and removing power ASAP is vital to limit the progression of smoke/flames. I would also add that at the accident record suggests that the majority of the accidents caused by electrically induced cabin fires where in aircraft with known or knowable preexisting electrical problems.

My person belief is that flight schools do place sufficient emphasis on the potential dangers of misbehaving electrical services. I am also surprised and disappointed with what seems to be a widespread UK attitude in UK light aviation towards the POH. It seems to me that the POH of a UK aircraft generally sits on some shelf still in its original wrapper and instead aircraft are operated on a series of locally made up procedures. The POH, especially the ones for later model Cessna's and Pipers has a wealth of valuable operating data and IMO should be well read and understood by every pilot.

[A and C]

Big Pistons

I don't think that the Piper or Cessna test pilots are the only input to the POH, I would guess that the company lawyers have quite a bit to say on the subject and most of what lawyers say is about protection for the client, not for the protection of the pilot.

A quick assessment of the situation is far better that rushing blindly into a situation that you could have prevented by a small amount of thought. I don't advocate keeping the electrics running for more that about 60 seconds, 30 seconds of thinking and trouble shooting and 30 seconds for the mayday call & 7700 on the transponder. At no time did I say reset any circuit breakers, I said TRIPP the CB's of suspect system, after all it could be a problem with the CB it's self.

Big end bob the electrical cable fitted to aircraft should be of a much higher quality than that fitted to cars and one of the requirements is for the cable not to support combustion, I doubt if an aircraft would catch fire in such a dramatic way as your car unless you did nothing about the problems that were becoming evident. The higher quality construction of aircraft electrical systems won't prevent a fire but it will give you more time to do something about it.