In a message dated 21/05/99 23:01:59 Greenwich Standard Time,
alan.stewart@cableinet.co.uk writes:
<< Why is it so difficult to measure fuel level accurately ? >>
I now regularly apply pressure to the fuselage vent sufficient to blow back
the sight gauge columns until you can hear bubbling into the tank. On
releasing the pressure a new and intact column is formed and you get a
consistent result. If you don't do this it is amazing how parts of the
column separate and hide out of sight, which is the reason for erroneous
results particularly if you run the level low and fly in turbulence..
I thought I had the ideal solution by measuring the pressure in a closed
column dipped into the tank with an ASI with dial calibrated for tank shape.
But it has recently started to give high readings which is bad news and needs
investigating.
I have never been so confident about fuel state since I had to abandon the
clear column dip--tube idea posted here last year. PFA didn't like it due to
having to pull the tube through an O-ring seal.
On sparks., I now refuel by pressurising a can with an tyre inflator which
pumps the fuel via a pipe plugged directly into the fuel filler aperture.
The system is thus totally enclosed and no vapour sees the atmosphere. The
vent must always exhale of course during the process, but there is no vapour
around at the critical time when the parts are joined, so any discharges are
safe. Saves your back too, not having to lift the tank !
Graham Clarke G-EMIN
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