Menu Sign In Contact FAQ
Banner
Welcome to our forums

Winter operations / lowest temperature for starting / preheating methods (merged)

And applying common sense I think unattended electric air blowers are just too much risk. Who knows if some plane in the hangar is not spilling fuel on the floor and then the remote controller heater might do the rest…

People might call me risk averse (it has worked for me so I am not about to change ) but the above is exactly my view. I have seen enough stuff go up in smoke. Especially any heater which contains a fan. If the fan packs up, the only thing which prevents an instant major fire (3kW in a small volume is an instant fire) is an overtemperature switch, which (you hope) is very close to the heating element(s). Fans in particular range from really crap to “ok but will stop working after x months/years”. For example every PC I have ever built has had a 100% fan failure rate, as has almost every piece of test equipment (including most HP and Tek ones). I now use Sanyo fans in PCs but at 30 quid nobody is going to use them commercially.

That is why oil heaters, which just have an element in the bottom and use convection, are so much safer. But they are very slow.

A heating pad on the bottom of the engine should be extremely safe – especially if it is low voltage, and the power supply for it (say, 24V out) is remotely located. It could even be just outside the hangar.

Administrator
Shoreham EGKA, United Kingdom

Below what temperatures are people or organisations here using pre-heat? Here it is usually like this that in cold temperatures it is mostly IMC anyway, but out of interest.

LSZH(work) LSZF (GA base), Switzerland

Here it is usually like this that in cold temperatures it is mostly IMC anyway, but out of interest.

I thought you were in the met business? It get coldest when there is no cloud cover and winter CAVOK is a fantastic time of the year for flying, especially since our typical airplanes have a lot more oomph. Usually we get an extended high pressure period in winter for a week or two.

The problem with electrical devices is that they need, er, electricity. That is often not available in Arctic regions, and not very easy on the apron of an airport.

In answer to the bit about the battery, in the conditions I am talking about, it is vital to remove the battery and keep it warm overnight. It simply won’t do anything if it has been cold soaked at -40°.

EGKB Biggin Hill

That’s another interesting angle. It would be very easy to keep the battery warm. The thermal resistance to ambient, in its box, is probably 1K/watt so 50 watts would do at -40C. One would put a 50W heater on the base of its box, although I would put a thick plate down there to prevent a hot spot, as well as a temperature switch.

Administrator
Shoreham EGKA, United Kingdom

It would be very easy to keep the battery warm.

I don’t know if they come in all sizes, but there are heated aircraft batteries on the market, e.g. from Concorde.

EDDS - Stuttgart

At LDZA you can call ground staff to provide the heating; they come with big truck providing heating tube directly to your engine and in 5 minutes you’re cranking the engine like in mid-summer – the downside it costs €25.

LDZA LDVA, Croatia

That’s another interesting angle. It would be very easy to keep the battery warm. The thermal resistance to ambient, in its box, is probably 1K/watt so 50 watts would do at -40C. One would put a 50W heater on the base of its box, although I would put a thick plate down there to prevent a hot spot, as well as a temperature switch.

The trouble is that you are either in a hangar or not.

If you are in a hangar, this is largely irrelevant. If you are not in a hangar, you still have the issue of where the power is coming from.

EGKB Biggin Hill

That’s a very good point, although you could heat up a battery pretty quickly, electrically. The battery itself could do it. It would too suffer in the low temps, but AIUI the low temp issue with lead-acid batteries in mainly the increase in internal resistance which prevents them starting an engine (say 200A). I am thinking of drawing 2A from it for say 10 mins.

If there are batteries with internal heaters on the market, I would think they must have thought about this. I reckon the heaters are intended for using the battery itself.

URL

Heated battery

Administrator
Shoreham EGKA, United Kingdom

Achim,

I am and that is why I know the situation here pretty well… We very often get a cold air lake here at ZRH and an inversion above it.

But I am no engineer. That is why I am asking.

LSZH(work) LSZF (GA base), Switzerland
Sign in to add your message

Back to Top