Graham has said "When refuelling some fuel gets pushed into the breather
pipe, (I've seen it many times.) After take off any air trapped in the
tank will expand as the aircraft climbs, the only way it can do that is
up the tank breather so fuel will get pushed out the breather, hence the
blue stains on the fuselage. The same thing happens if the aircraft is
refuelled
cold, then the sun comes out and we warm up."
My recent experience with G-IANI and G-IRON is that the smell is from
fuel trapped in the breather. Remember the inside end of the breather
is turned up so any fuel which enters is trapped in the "U" created
before the breather turns up to the roof (or top of filler neck). This
means the connection of the F09B fitting to the vent tube is wet with
fuel for long periods. Even with a good clip the seal between the F09B
and the plastic tube is very poor (this seems to be because of the way
the F09B is machined). We realised this when the joint was actually wet
with fuel when G-IRON was accidentally slightly over filled.
We have replaced the lower end of the vent pipe (from the F09B fitting
to half way up the filler neck) with rubber pipe which seals well on to
the F09B. This introduces another connector (and so potential source of
leak) but seams to have cured the problem.
Ian Rickard #505 G-IANI XS Trigear
Europa Club Mods Rep (Trigear)
e-mail mods@europaclub.org.uk
or direct g-iani@ntlworld.com
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