Grandmother Goes Down at the Pole

On Mon, 22 Dec 2003 21:19:13 GMT,
(Corky Scott) wrote:

I understand what you are saying. I'm just adding some information:
Aviation fuel is not formulated like auto fuel, it's specifically
formulated to remain viable after long storage.

I agree it's actual life will be be longer than Mogas ( that's
verified by the more stringent potential gum specification in ASTM
D910 ), but aviation gasoline has also to be retested regularly by an
approved and qualified laboratory to verify that the products is still
OK. IIRC, it used to be every 6 months - with the major concerns being
the loss of volatility and decomposition of lead compounds and their
scavengers. Avgas is made from more stable hydrocarbon fractions, and
doesn't have the unstable detergents present in Mogas, so it should
pass several retests if containers are full, hermetic, and kept cool
and dark.

But if it were stored there, it would last a long time and would work
fine for people who used that type of fuel.

Being cold and dark, the Avgas may last longer down there than it
would in the tropics, but it still has to be sampled and retested
every 6 months ( I've just checked the military specifications, which
used to have the longest retest intervals ). Defstan 01-05, it's in
Table 2 on page 285 of page 334 - don't go to this link unless you
want a large download of all military fuel and lubricant
specifications!.
http://www.dstan.mod.uk/data/01/005/00001300.pdf

The Antarctic bases didn't hold it because they don't use it, and once
it's passed "retest by" date it's usually downgraded to Mogas, as
happens if it doesn't pass the retest. It can't be used as Avgas (
it's formally quarantined ) until a retest verifies it's OK. If the
retest period is allowed to expire, it may have to pass a full
specification test before reapproval, depending on the local
regulations.

I hope this post doesn't sound impolite or abusive to you, as you
obviously wanted to add some data, but the storage constraints on
Avgas mean it has to be regularly retested before it can be accepted
as fuel for aircraft. Avgas is usually more stable than Mogas, but it
still has to be within a current test period.

Bruce Hamilton