Having recently re-arranged/replaced all fuel lines=2C vent lines and sight
tube I am still at odds with two items:
1. What exactly is the reason again for having the tank vent in the airstre
am instead of a static position? Are we doing this because everybody else h
as always been doing it or is there a real safety aspect ? I have been give
n six reasons=2C but none of them make sense to me and there is no proof. A
static vent can handle any air flow in and out of the tank. I don't see th
e need for pressurization=2C especially since this must be miniscule=2C in
a pump driven system. Maybe in a gravity fed fuel system it might make sens
e=2C or where there are two fuel tanks. Some of you have moved the vent to
the bottom of the fuselage=2C where it could easily be clogged by mud or in
sects. It has happened twice to my pitot tube.
2. Why has no PFA/LAA or other inspector ever pointed out the fact that the
drain tap arrangement is completely useless ? There would have to be an aw
ful lot of water in the tank before any of it would show up in a drain cup.
But it could get to the engine in a steep descent. The obvious reason is th
e high point of the fuel exits and the high barb fitting on the taps themse
lves. This would be especially so in a mono. The only sensible installation
would be flush fitting taps in the tank itself. I am tempted to remove tha
t plumbing and use the tap on my mini-gascolator .
Karl
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