Tracy Crook wrote:
The subject of gascolators recently came up so thought I'd send along this
experience which began on yesterday's flight home from Treasure Coast
airpark, about 231 miles southeast of Shady Bend.
Was at my normal 12,500 ft cruising altitude over Orlando's class B airspace
when I noticed the fuel pressure dipping intermittently about 5 psi
(definitely not normal) and getting worse. Suspected a fuel pump going bad
so switched on backup pump. Pressure stabalized but still jittering around
2 psi. Left both pumps on and zigzaged my way home always staying within
gliding distance of an airport (thank god Florida is liberally sprinkled
with private airstrips and my Anywhere Map GPS does show private strips).
Arrived home OK and listened to fuel pumps with engine off. They both
sounded like they were making more "gear noise" than normal.
Dug into the airplane today looking for the problem. Picture of the
gascolator screen attached shows the trouble . Screen was completely
blocked with debris. The white flakes are pieces of tank sloshing compound.
(DO NOT USE THIS STUFF) Most of the blockage was from tiny lint fibers (dark
stuff) that always turns up in the screen. I just let too much time go by
between checks. It has been more than a year since last cleaning.
The only way engine was getting fuel was due to the pumps sucking so hard
that the screen was pulled into a cavitiy causing the edge of screen to lift
in one place. This allowed unfiltered fuel to pass. Sure glad I had another
filter down stream of the pump to catch whatever got by!
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com
I run a separate fuel pickup, screen and gascolator for each fuel pump.
This way if the main has any problems I can switch to the backup
pump that should be clean as it is only used for an emergency.
Ken Welter
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