Mv727cap@aol.com, jas56d@msn.com
In a message dated 12/08/2001 2:20:47 AM Pacific Standard Time,
carl@flyers.freeserve.co.uk writes:
> For what it's worth
>
> I can see no logical reason for using two Gascolators in the fuel system,
> other than to add extra weight, extra connections, and the need to check on
> an extra item.
>
> The idea that an additional source of filtration will make it less likely
> that dirty fuel will result in an engine stoppage is nonsense (apologies!).
> If the fuel is so dirty or contaminated that it will block the first
> gascolator, then it will almost certainly block the second one as quickly.
> The only logical use I can see for a two gascolator arrangement is to give
> early warning that there is a problem with the fuel system. This can be
> achieved just as easily by fitting a fuel pressure gauge.
>
> I know I have said this before and I don't think that I can overemphasise
> it but contaminated fuel should simply not be allowed to get into the fuel
> tank in the first place (obviously water is a different matter). It is very
> easy to devise an arrangement that filters the fuel as it is being poured
> into the fuel tank. This is by far the best way of preventing a blockage
> in the fuel system.
>
> A single gascolator system is perfectly satisfactory provided the fuel is
> clean, and most importantly the gascolator is regularly checked regularly
> for debris.
>
> The gascolator on our aircraft is situated so that it can be reached from
> below the aircraft and checked in the normal way with the standard fuel
> tester. The bulkhead on which it is mounted can also be removed for
> regular checks of the gauze strainer. In addition there is a fuel pressure
> gauge installed in the system.
>
>
Well, here is my take on this -- if there is a problem with a plugged
filtration system -- either a gascolator or a filter, it does not necessarily
have to be a sudden catastrophic event. It can take place over time between
inspections. In that event, if there is a blockage there is adequate time to
switch to the reserve tank and get the airplane on the ground. Without this
option, the engine is dead - you now are a glider. Wait! I am a glider!
Monitoring the fuel pressure should provide you with information of a
clogging system, but is information only and provides no action option to
resolve the situation in flight. I suppose I am used to the redundancy of
multi engine airplanes.
I don't think the weight penalty is significant with the Andair mini
gascolator. The preflight inspection would be to drain both at the same time,
which would be mounted side by side. I have a twin Comanche which has a
similar system, except it is 2 tanks feeding 2 engines rather than one.
Always open for input,
Dave
A227 - motorglider
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