>We had an occurrence with ZK-UBD this week which has now confirmed my
>decision
>to reinstate the dual fuel filter layout. I will also be keeping the
>gascolator
>in its existing position at the lowest point of the fuel system prior to the
>aft mounted 914 fuel pumps.
Tony,
I think careful thought is needed here. The whole point of a gascolator is
that it can be checked before every flight without invading the fuel system
Checking the Purolators involves disturbing joints in rubber pipes made
with worm drive clips. If this was done before every flight the pipes would
need changing every 10 hours or so.
A visual check is not adequate, IMHO, because polyethylene swarf is almost
invisible, as is the sludge or jelly that sometimes appears with bacterial
contamination. I doubt if water would show up either.
I am far from convinced that putting two filters in the system improves
safety because of the observed tendency of these filters to gradually block
up. Admitted the option of changing tanks, and therefore filters is there,
but if there is enough rubbish to block a gascolator, (preferably an
Andair, not a cheaply made leaky unit) then it may well contaminate main
tank and reserve and block both filters.
Graham
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