Hi All,
I am surprised that anyone ever gets blocked filters after the initial
shakedown. I know it is difficult to clean out tanks after build but it's
definitely worth pumping a few gallons of fuel through the system before
assuming everything is clean.
If you have dirty fuel in your tanks this is an issue that should be
addressed first rather instead of relying on the fuel filters to do their
job. I accept that some of us have less control over what we put in our
tanks than others (ie: if you are purchasing fuel at the airfield pumps).
In the early days I recall that clogged filters were an issue for some
builders. The filters were becoming overwhelmed by large amounts of crud
which should never have been there in the first place - I do not believe
that changing the size of the filter mesh would address this particular
issue.
Personally I never liked the factory system and opted for a gascolator setup
instead - nothing fancy like an Andair, just the cheap kit builders one
available from LAS or Aircraft Spruce (I priced one at the LAA yesterday and
they are selling for 60) . The beauty of the setup is that any large lumps
of crud (or water) tend to settle in the bottom of the gascolator bowl and
will be drained off when you do your do your daily fuel checks - very little
muck reaches the filter mesh at the top of the bowl (this is a 120 micron
screen).
We are fortunate in that all our fuel is from cans which we insist on
filtering through a fine mesh funnel and we have never found any signs of a
clogged filter. It is worth noting that metal fuel cans generate their own
debris as the internal paint on the cans tends to flake off and if not
filtered would cause problems if not pre filtered.
For those who have to rely on airfield based supplies if it should be
possible to carry a filter sock (wire or nylon mesh) which could be dropped
down the fuel filler opening to ensure the cleanliness of any external
sources of fuel. This could even be a permanent installation.
Additionally as a backup, a fuel pressure gauge which would give a visual
warning of low pressure due to a filter blockage.
Carl Pattinson
G-LABS
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Pete Lawless
Sent: 01 September 2013 11:08
Subject: Europa-List: Fuel filters
Hi John
I have the original glass filters and am very happy with them. In the first
few hours of a new Europa they do get blocked and mine needed cleaning every
5 hours or so for the first 25 hours and on one occasion at about 10 hours
caused fuel starvation on the climb out. Then less frequently cleaning
until the tank settled down at about 100 hours. At 550 hours the filter now
need a clean about every 50 hours.
My filters are installed under the seats protected by a Perspex cover, as
per the original Classic layout. I inspect them BEFORE EVERY FLIGHT. The
beauty of the glass container is that you can see what is going on, all that
is needed is to pull up the seat cushion and look. Cleaning is very easy
you just change the filter screen for a new one and wipe the inside of the
glass.
I would be very reluctant to install a filter unit I could not inspect
without taking it to bits.
Pete
Classic #109 Rotax 912UL
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of John Wighton
Sent: 01 September 2013 09:23
Subject: Europa-List: Re: Daily Mail report of father and daughter fatality
The photos taken in 2002 of the crashed aircraft are shocking and hopefully
not an indicator of the condition she was in at the time of the accident.
But l have to say that if the level of neglect extended to the systems,
especially the fuel system, the cause of the incident may easily have been a
blocked filter. According to a close friend of David, whom l spoke to
yesterday at the Rally, the accident occurred at full power in the climb
out after refuelling. If so the classic case of power starvation due to a
blocked filer is a possible cause. I note that the photos show the inline
filter used is the standard glass tube variety. Blockage of this type of
inline filter has caused many incidents and at least one written off Europa.
Analysing this filter shows it uses a 22 micron sized mesh. This is way
smaller than the 100 micron (largest) stipulated by Rotax. I had a stoppage
due to a blocked primary filter (same type) a few years ago, this led to a
hasty decent into Elstree using the reserve feed (thanks for the fire cover
guys). The filter was partially blocked with translucent material. It ran
on the ground but would not feed fuel to the goverened 5000 rpm of my AP332
controller.
Having thereafter spent a year in a constant state of fuel feed anxiety l
changed them for Andair filters which have a 60 micron filter size. To date
these have proven extremely reliable (100%).
In 2012 l contacted Andy at Andair to ask if a version for 1/4in bore fuel
lines could be made. He said it was quite easy, just a CNC program change,
the filters would then have a push-on nipple type end and not require screw
fit unions (as in my installation). Some discussion occurred with Andy
Draper about the mod.
Yesterday l checked with Andair, he had not got around to adapting the CNC
code and hence nothing had occurred at LAA Engineering.
If it turns out that the cause of the stoppage on GBXS was filter related
(this is speculative but informed on my part) we should support some action
which will lead to changes in the use of these standard glass tube filters.
A possibility for Europas could be a new filter, perhaps the Andair version.
I shall write to the LAA with my concerns over the continued use of the
glass tube, 22. Micron filters. If any Europa flyer, or other aircraft
operator with the same filter type, can supply information regarding the use
of these filters it may assist in deciding which way to go. Information
such as frequency of inspection, frequency of cleaning, stoppage or partial
blockage info, leaks, other issues will br gratefully received and treated
in confidence. Likewise any info showing satisfactory in service history is
also welcome. Please post info or email direct to me.
John(dot)wighton@ultraflight.net
John Wighton
Chief of Stress
Pilatus Aircraft
--------
John Wighton
Europa XS trigear G-IPOD
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