My XS Tri-Gear has always smelt of petrol, whatever the level of fuel in the
tank, until the air is changed during flight. When opening up the smell is
quite nauseating. Worse when using Mogas than it is with Avgas, but always
very obvious. I have come to the conclusion that it must be a combination of
all the things people have mentioned with perhaps the greatest contribution
coming from the fuel filler pipe - because of its physical area.
I intend to add the Europa mod to cover over the filler pipe. I would also
like to replace all the rubber fuel lines with something less 'porous' if
this is practical - and then look carefully at the Avelec fitting in the top
of the tank.
Mark G-CHET
-----Original Message-----
From: owner-europa@post.aviators.net
Subject: Fuel smell in cockpit
I have been watching with interest the exchanges on the Forum about fuel
smells. My Europa exhibits this problem during and immediately after
take-off, but only from time to time.
On 6th October I flew my aircraft - twice - for the first time for six
weeks. Absences abroad and in UK, and a 50 hr check, were responsible for
the long pause.
After I had completed the engine run at the end of the 50 hr check,
there were 10 litres of Avgas in the main tank, according to my Avalec.
On 6th, before my 1st flight, I uplifted 30 litres and got airborne
about 10 minutes later. There was a very strong smell of fuel as I climbed
away, which persisted for 5 minutes or so until the cockpit air had been
changed by the NACA scoop. The second flight that day was 4 hrs after
landing from the first, and there was no smell.
Today, in an attempt to isolate the cause of this problem, I carried out
the following sequence.
I flew for 15 minutes, with a start fuel level of 26 litres. There was
no fuel smell before, during or after take-off.
Before the second flight, I wrapped and sealed polythene around the
rubber pipe part of the fuel filler (I have the baggage bay extension); this
seal included the breather pipe and the fuel sight gauge pipe. 15 litres of
fuel were then added; during the refuelling I kept my nose close to the area
of the tank top through which the Avalec is fitted. There was no smell of
fuel during refuelling, and when I then took off with 38 litres recorded,
there was no smell of fuel at any time during the 10 minute flight.
I had fitted the seal around the rubber pipe part of the tank filler
because there have been some messages on the forum suggesting that there
might be some porosity in the rubber pipe.
After the second flight, I removed the polythene seal, and then added
another 15 litres. Again, there was no smell at the tank-top during
refuelling, and no smell during the flight, which started with 52 litres in
the main tank.
I am mystified by the results of this simple trial, when compared with
the first flight on 6th..
I am now wondering whether there is an imperfect seal at the tank-top
Avalec plate, which might have been aggravated on 6th October by a refueller
who filled the aircraft up much faster than today's duty refueller, who is
always very careful. I should point out that I have made a fibreglass cover
which fits over the tank top to prevent damage to the Avalec probe.
Who has any other suggestions about this fuel smell problem? Are those
of you who suffer badly using the Avalec probe, or a similar probe fitted
through the tank top?
There has been so much about this problem on the forum that it would be
nice to try to isolate the problem once and for all.
Best wishes to you all,
David
UK 265 G-BZAM
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