Gascolator

: That design is fine on a tractor, but is not so great on an aircraft.
: It's amazing what junk some of these aircraft manufacturers used (and
: had certificated). They couldn't get away with the glass bowl, but they
: did the minimum required to make it work to get the airplane
: certificated.

That's true, but there's history involved. Lots of manufacturers' parts were
made cheaply as commodity parts at the time. Those were then grandfathered in to new
designs, unless there was some reason to change them. IIRC, O-rings weren't even
common until after WWII... the rubber washer in the gascolator is more old-school and
predates WWII. An airplane is generally better built than a tractor, but a 1939
tractor and a 1939 Piper are more similar than different. Don't confuse "junk" with
"old technology" or "inexpensive construction." They're not necessarily synonyms. I
would (and apparently am) arging that the original gascolator is perfectly adequate
unless abused (e.g. warped top, bad seals, stripped threads, etc).

: It isn't necessary to drain the gascolator completely. In fact, when I
: was a student pilot, I was taught to activate the fuel boost pump while
: sumping, which would ensure that you couldn't accidentally drain the
: gascolator. I think this is overkill and I no longer do this, but it's
: probably not bad advice for a student pilot.

OK, you got me. Draining the gascolator could be considered operator error as
well. It doesn't have to be done, but some people do it anyway. In any event, since
when has regulation made sense? (Since my gascolator is pressurized now with the fuel
pump on, it *really* squirts out if you sample then)

: I did call and talk to the guy this morning. He said that, in most
: cases, the 90 degree fitting and extension usually does the job, but in
: some cases, folks have remote mounted the valves. I don't want to
: remote mount mine, so I might go take some measurements to make an
: initial determination as to whether it will fit.

I wouldn't relocate either... KISS. More parts, fittings, mounts to fail.

: The bottom line is that if I elect to keep the Piper gascolator, I'm
: stuck paying almost as much for just the bail wire as for the entire STC
: gascolator unit. I'm sure that you can see why this is of such
: interest, and I'm surprised that it hasn't received more attention.

I agree completely for your situation. The original post seemed to imply a
rampant and persistant problem with these old gascolators. I didn't know it was
rampant.

You may want to look at salvage yards. Also, since it *is* just a piece of
wire, you can fabricate one yourself ("owner-fabricated parts") if your A&P/IA is OK
with it.

-Cory

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* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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