Fuel anti-freeze additives - do you use any?

There is an Av Gas Prist also.

Al G


"Jim Macklin" wrote in message
news:2_NZg.12899$XX2.1716@dukeread04...
A Duchess at 25,000 feet? Sounds a little like BS to me or
is that just an urban legend?

Gasoline with water in the fuel system needs to be properly
sumped, drained, purged of that water. If you have an
underground fuel farm and pump directly into the airplane,
any water in the mixture will take an hour or two minimum
for the water to collect and settle into the tank sumps. If
the fuel is pumped from storage into a truck and taken to
the airplane, the water still needs several hours to settle.

If the maintenance of the fuel trucks, filters and service
practice are sloppy, you'll have lots of water in your
tanks. The fuel in an underground tank or a truck needs to
settle and then all the water drained. Fuel filters need to
be service daily. Aircraft maintenance means that fuel cap
seals must be inspected and replaced. The airplane needs to
sit for two hours or more after being fueled and then the
fuel sumps drained of all trapped water. Then depending on
the aircraft model, the plane needs to be rocked so that
water trapped in fuel tank wrinkles (Cessna AD) will move to
the sumps and can then be drained again.
In automobiles, chemicals such as alcohol are often sold as
fuel system driers, nut alcohol should not be added to
aircraft fuel. The use of Prist in the proper quantity and
mixing method doesn't hurt, but Prist is primarily for Jet
fuel which holds more water, grows fungus and does get thick
at low temperatures.

A Duchess at 25,000 feet?


"Peter" wrote in message
...
|
| "John R. Copeland" wrote:
|
| Cold avgas should be no problem, assuming no suspended
ice crystals.
| Take care to keep your fuel clean and dry.
| I often fly in the low flight levels where temperatures
can be even lower.
| The cold-soaked fuel flows just fine, including using a
transfer pump to
| move wing-locker fuel out into the tip tanks.
| I've never had any avgas problems at those temperatures,
| but cranking the starter against very cold oil has
defeated me too many times.
| Heated hangars are my favorite choice.
|
| This is Europe, where heated hangars are a luxury
available to the
| chosen few
|
| The specific concern wasn't the stuff flowing into the
tank. It is
| freezing in the pipework, especially in the injection
tubes (IO540-C4
| engine, in my case) which are very thin and exposed to the
full 150kt
| airstream.
|
| There have been various cases of avgas freezing in fuel
pipes, and the
| pilot having to descend all the way down to god knows
where to restart
| the engine(s). And it's happened to twins too; one pilot I
met
| recently had to descend (a Duchess) with a dual engine
failure from
| 25,000ft to 2,000ft over the sea, 100nm away from any
coast, before he
| could restart. The initial temp was -25C.
|