Hi! Nigel
I'd also seek to remind everyone about the need to ensure that the exit
hole drillings through the tank connectors are expanded at their
intersection, a check which needs the finger filters removed and
replaced.
I also can confirm that I use a Mini Andair gascolator and find it to be
excellent and without fault, cleaning it's filter at every service
reveals only the most slight contamination.
On Peter Rees problem ......is the filler pipe on your aircraft the
original early one? There was a mandatory change of filler pipes and I
wonder if yours slipped the net?
Regards
Bob Harrison G-PTAG
-----Original Message-----
[mailto:owner-europa-list-server@matronics.com] On Behalf Of nigel
charles
Sent: 04 August 2006 21:19
Having followed the air filter blockage discussion over the last few
years I would like to offer the following as a summary of what has been
learnt so far and what I think can be done to minimise the problem.
1. There are two main types of blockage.
a. That due to swarf from tank drilling.
b. That due to fuel impurities.
2. The swarf problem once solved, should not reoccur but even better not
to have it in the first place. This is not an easy task because it is
difficult to see and it tends to stick to the tank initially due to
static charge. To minimise the spread of any swarf, first place the tank
so any drilling is done from underneath. This stops the swarf falling
away from the hole. Drill slowly to avoid the swarf being thrown away
---From the hole. When drilling is complete wipe the swarf around the hole
back through the hole with your finger. If holes are drilled in the top
of the tank for fuel quantity senders there is access to use a pipe on
the end of a vacuum cleaner hose to suck out any remaining swarf. As a
final measure the tank can be rinsed out with water. Before connecting
up the fuel piping forward of the firewall use the electrical pump to
empty the tank several times to catch any contamination before any
engine runs. This can also be combined with calibrating the tank
contents. Also check the filters/gascolator for contamination after each
engine run. Taxi checks will also help to shake the fuel around to
dislodge any remaining swarf.
3. Choice of filters or gascolators. The standard filters will not
collect much swarf before they block up. Larger filters help but a
gascolator is better still. A gascolator also provides an extra water
trap and the filter used in the Andair gascolator is fine enough to
prevent water passing through. Removing, emptying and cleaning/replacing
filters is more difficult with inline filters than gascolators. It is
also easier to incorporate gascolators into a rigid pipe system.
Remember that any rubber hose used should be replaced every 5 years.
Rigid pipework is lighter and a fit and forget system.
4. The only reported case of an Andair gascolator blocking is due to
fuel impurities sticking to the filter. The risk of this is minimised if
fuel is bought from sources with high turnover such as supermarket
filling stations. Another protection measure is to pour the fuel through
a 'Mr Funnel' funnel. This uses the same type of filter element as the
Andair gascolator so should prevent any contaminant getting through to
the gascolator.
5. Removing the gascolator bowl after each flight initially, reducing to
after each service once hours have been accumulated will show up if any
swarf has been missed. Different versions of the Andair gascolator have
different means of attaching the bowl. The bayonet fit version is the
most difficult to remove and refit due to the tight tolerances of the
parts and the seal. This is made easier with a smear of grease between
the parts in the region of the seal before refitting.
I hope this list of points is of help, particularly for those of you
still building. There may be some more tips others can add to this list.
Regards
Nigel Charles
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