Hello Raimo,
> For me personally I have fire extinguisher onboard mainly
> if something happen on the ground for my plane or neigbours one.
If it is for on the ground, CO2 would be fine.
> It is not easy to imagine cocpit fire situation airborne but if that occurs,
> pilot would be happy if he has Halon.
I don't think so. Your main objective is getting down, as fast as
possible. Fruitless attempts to extinguish the fire and partly choking
yourself is not compatible with preparing an emergency landing.
About your example:
> About 20 years ago one
> 2-engine Pipers cocpit flamed because choke (uncorrect word) fuel line
> got broken and pilot caught fire. He has not (Halon) extinguisher
> and elected to jump out as a living torch.
Suppose he had Halon, and then? You can maybe extinguish this fire, but
after that the pilot is still soaked with fuel. There was something that
ignited this fuel, and this something is still there. The fuel is also
still there. After the Halon is gone, the situation is likely to repeat
again, but this time without the Halon.
> Same could happen to
> Europas tube type fuel gauge. It is in the cockpit like are those fuel
> breathing lines also. I would be happy if they all were outside.
So, work on that! I have immediately abandoned the idea of using this
sight tube. Instead, I have a fuel flow sensor (also good to detect
leaks while airborne), and two separate fuel level sensors. I use a
one-way valve for the fuel return line, and have the tankvent arranged
in such a way that it won't leak fuel, neither upright or inverted. The
whole filter and fuel pump assembly is mounted in a sealed box, vented
to the outside. If one of these dozen jubilee clibs or tee's start
leaking, it is not going to make it into the cabin. I can't eliminate
all the risks, but at least minimize them, and make all situations where
Halon could be of any use most unlikely. If the tank splits wide open,
well, can't take away that risk, but then again the Halon would be
useless in that situation.
> Lets imagine you find some fresh fuel smell during flight.
> Maybe your right leg or right hand also get wet about fuel.
>
> ***What we should do in this situation? ***
>
> Immediately landing of course.
> With electrics of or not? If you elect to switch off, there can be
> in that moment a fateful spark during switching off.
If you have your system setup properly, there won't be a spark due to
the switch off. The soleonid should be sealed by itself. The control
current is small, and by using a diode over the soleonid, and a small
condensator over the switch, you won't get a spark. You will get a spark
though if you leave the master switch on, and the landing is a little
bit rough. Probably before that time you will get a spark from your trim
motor, flaps, or various other little electrical critters on board.
Frans
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