John, I would endorse the value of a low fuel pressure warning light. I have
a simple pressure switch set at 3 psi triggering a bright red light in front
of my nose. If I deliberately or inadvertently run the main tank dry it
lights up in time to switch over to reserve without the engine stopping.
I remember also a story of the early 914 company demonstrator having
fuel starvation related rough running due to fuel tank derived gunge in the
gascolator, which cleared well enough to get them home when the second
electric fuel pump was switched on - which suggests that a fuel pressure
alarm system would give reasonable notice of impending filter/gascolator
blockage to allow the extra pump to see you home.
Regards, David Joyce, G-XSDJ
----- Original Message -----
From: "John & Paddy Wigney" <johnwigney@alltel.net>
Sent: Wednesday, August 09, 2006 8:45 PM
Subject: Europa-List: Fuel supply reliability discussion
> Dear Europaphiles,
>
> There was some recent discussion regarding blocked fuel filters during
> early test flying on the Europa. Some of these stories have happy
> endings, others have resulted in accidents. Before I flew my plane in
> 2001, there had already been quite a lot of discussion on this same
> subject and I had concluded that if the Rotax 912/912S/914 is supplied
> with fuel, it will generally run without trouble. If one has dirty fuel
> for whatever reason, any filter system will block eventually. I
> therefore looked for a system which would (1) provide an alarm if there
> was a loss of fuel pressure at the carbs and (2) provide an alarm when I
> was low on fuel (4 gallons say).
>
> I am sure that there are many ways to achieve these objectives, but my
> installation is a Grand Rapids EIS with a fuel pressure sensor which is
> located between the engine mechanical pump and the carburetors. The
> pressure alarm is set at 0.5 psi. My fuel filter is an Andair GAS125
> mini gascolator and contrary to the experience of others, I have never
> found more than very minor trash in the bowl. I have no idea why I have
> seen so little trash and no slime when others have had significant
> stoppages. I installed the filter under the baggage bay shelf. I also
> have the fuel flow sensor and totaliser option which gives accurate
> indication of consumption and when the '4.0 gallons remaining' alarm
> goes off, I know I need to look for a fuel stop. I have tank level
> capacitance gauges so I can always cross check.
>
> In 500 hours, I have only had the fuel pressure alarm go off once
> (apparently due to an air bubble in the system after some fuel hose
> replacements - the problem cleared when I switched on the electric
> pump). I have never checked the interval from low fuel pressure alarm
> and lack of fuel to engine stop but I believe it is approximately 20
> seconds; this is quite short but at least it gives a brief warning of
> impending stop.
>
> Cheers, John
>
> N262WF, mono XS, 912S
> Mooresville, North Carolina
>
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