Aircraft storage

On Sat, 18 Dec 2004 20:55:14 GMT, "#1ACGuy"
wrote:

How long can an aircraft sit unused before the fuel gums up and contaminates
the fuel system?
snip
I ask because some of these planes seem like they're for sale for over a
year or more, and I wonder what kind of problems they have due to sitting
besides the obvious dry startup with no oil on the cam etc. (as if that
isn't enough of a problem)

My guess is that most planes for sale are still flying regularly.
There are exceptions to this (ramp or hangar queens and owners forced
into selling because of financial distress), but most owners realize
the worst thing they can do to an aircraft is not to fly it.

Regarding storage, you can 'pickle' an engine to allow VERY long term
storage, however as you point out this does not address the fuel
system. Some planes have bladder tanks, and I imagine it is quite bad
for them to sit dry. Probably the same goes for the fuel lines. Not
to mention the gyro instruments, vac pump, and vac lines.

-Nathan

Thanks. I'm just trying to get an idea of how avgas stores. I did find some
useful info on the Chevron site.
FWIW, I grew up in Ohio, and remember some stations selling white gas from a
small tank in the back, which I always related to the likes of Coleman fuel.
What I do know for sure, is that seasonal use small engines such as snow
blowers, lawn mowers, or rototillers would be fine after long term storage
as long as we used white gas in them. I remember several neighbors trying
this with gasoline, and no go. Answer from the shops that had to repair
their stuff was always 'shoulda used white gas'. Today I just treat the fuel
in my motorcycles with Sta-bil. People on the motorcycle boards that live in
cold weather areas say that the regular unleaded fuel they get is even
shorter lived today than it was in years past, so they make sure to use
Sta-bil. I don't think anyone uses white gas anymore. Av gas just seems so
much more refined. It quickly evaperates without any lingering smell,
similar to lantern fuel. I don't know how people that run auto gas in their
planes keep everything from smelling like gas all the time. For instance, I
sure wouldn't want to put my fuel sampling cup back in my flight bag after
sumping tanks with auto fuel in them. Seems like everything in the bag and
the plane itself would smell like gas for weeks. Av gas, no problem, no
smell.
Alex

My guess is that most planes for sale are still flying regularly.
There are exceptions to this (ramp or hangar queens and owners forced
into selling because of financial distress), but most owners realize
the worst thing they can do to an aircraft is not to fly it.

Regarding storage, you can 'pickle' an engine to allow VERY long term
storage, however as you point out this does not address the fuel
system. Some planes have bladder tanks, and I imagine it is quite bad
for them to sit dry. Probably the same goes for the fuel lines. Not
to mention the gyro instruments, vac pump, and vac lines.

-Nathan

The term "white gas" as used in southern US might have come from
standard oil's White Crown Gas which was of premium octane.

I think of white gas as Coleman fuel. It needs to be only a
hydrocarbon with no requirement for octane ratings etc. Maybe it would
work in small low compression engines, at least others say it will.

I had a mostly empty stored can of Coleman fuel go royally sour after
several years. Allowing the surface to be exposed to air might have
caused it. The same thing probably applies to autofuel, but maybe to a
lesser degree. Colder temps will probably also improve any fuel's
storage life.

I agree autofuel stinks, although I understand that is due to the MTBE
components allowed for octane enhancement. Ethanol laced fuels (not
permitted of course for aircraft use) will go bad in just a few months.