On Thursday, September 13, 2018 at 11:21:01 PM UTC-7, Mike Borgelt wrote:
On Thursday, 13 September 2018 20:46:33 UTC+10, Emir Sherbi wrote:
Mike,

For me is weird to fill the glider with 12l of explosive liquid behind my back that makes explosive fumes with a lot of electronics around.

You have risks all the time, even without a motor.

Yeah, but a Halon extinguisher has a fighting chance of putting out a jet A-1 fire. Try putting out a lithium battery fire. The youtube clips of lithium battery fires are quite entertaining.
There's no reason to have explosive fumes from fuel in the glider with proper tank venting and drains. The piston engine motorglider fires that I know of have been mainly caused by problems with the fuel plumbing. Using crummy automotive fuel fittings instead of AN aero types. In the last few years the German glider industry has been a little better but the Quintus engine I fixed recently still had a lot of automotive type hose clamps in the fuel system which is interesting as the fuel injected system runs at 3 bar. A leak could easily ruin your whole day, particularly with the proximity of the hot exhaust not far away.
I have nothing against electric gliders, the motors controllers, props etc are fine but the batteries are a problem, which is the conclusion I came to in 2008. Ten years on I still haven't seen anything to change that conclusion.
BTW didn't the Siemens test electric airplane (an Extra 300) crash recently, killing the pilots? The report I read said that it caught fire in the air.
We had an Antares in Australia catch fire a few years ago while parked in a hangar at Narromine. Seems there was a short between a point on the circuit board of the 300 volt to 12 volt converter and large hole got burned in the aluminum cover until the arc was no longer able to bridge the gap. Fortunately nothing else caught fire.
As I said, experiment away. If nobody does it, progress will not be made.

Mike

The production of Halon ceased January 1, 1994, at least in the States.