Nigel Charles wrote:
> The Andair gascolator has a screen which allows fuel to pass through it but
> not water.
Where's the water go if the gascolator bowl is filled with water?
> Even in the damp
> environment of the UK, in one year's operation I have not yet found a
> single drop of water whilst doing these checks.
That's indeed the practical side of it. In most all accident reports
here, water in the system is from rain water and defective or poorly
designed filler caps, to which the Europa appears immune. It's rare
now that one can buy even auto fuel which is water-contaminated, and
the volume of water produced by tank condensation should be too small
to be hazardous. At least, I can find no accident report where such
was proven the source.
A gascolator cannot evacuate in pre-flight all water that's in the
tank unless it's at the very lowest point, which requires it be
mounted in part external to the fuselage. My concern is thus if you
found a good ounce of water in a gascolator, and never a drop before,
would you just drain some more and go flying? Likely a previous bad
load of fuel, with unknown how much is still in the tank that you
can't drain.
Along these lines, I just found FAA's web site will quickly give you
history back to day one of all its rules. Well before WWII, in lieu
of a sump drain, only a single drain (a sediment bowl or gascolator
not then required) was legal if at the lowest point - old CAR 4a.607.
There was no stated requirement that it be able to drain all water
---From the tank, perhaps explaining why the drain had to be accessible
---From inside the cockpit - presumably during flight? :-) At least it
now explains the weird setup on my friend's 1928 New Standard
bi-plane.
Skipping a dozen regulatory iterations, the current rule here is
recent (1993), requiring at least one drain capable of removing _all_
water from the tank. This is not the case with my 1972 AA-5 (no
gascolator, but sediment/water trap in an inline boost pump, no drain,
and not at lowest point). The tank drains can permit potentially
hazardous amt's water to remain in the tanks and thus would bust
current rules on two scores, but with separate, monster drainable sump
tanks much larger than required, it do indeed work. I've done over 20
annual inspections on her, have had occasional filler cap problems and
know exactly where the rain water winds up, but never a hazard to
flight.
So lacking any sump, is why I think tank drains are peace of mind. At
least, in combination with a gascolator at any level in the system
really, it approximately brings her up to standards as they were in
the early '70's!
Best,
Fred F.
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