Fuel anti-freeze additives - do you use any?

"Peter" wrote in message ...
Hi All,

I fly a TB20 (avgas). The flight manual recommends various things but
does not give any ambient temperatures below which they should be
used.

The whole subject is a bit vague anyway, with stories circulating
about avtur additives being different from (or identical to) to the
avgas ones.

What would the experienced pilots here recommend, for an OAT down to
say -20C or -25C?

Peter.


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.

"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.


As I said earlier, keep your fuel clean and dry.
It's the suspended water, not the avgas that freezes.
One point of difficulty is the fuel screen, which ice crystals can plug.
I've never before heard of avgas congealing in the injection tubes.

Flight Level 250 in a Duchess? Better ask him again.
Beech lists 16000 feet for the Duchess' service ceiling.

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.
|

"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.

I've had the "Twin glider syndrome" in a C-340. South of Klamath Falls,
Or., at FL 220, -30C, The fuel flow for the left one started to twitch, and
whithin 3 minutes, the engine quit. The right one followed about 5 later.
Tops were about 20,000, and the 340 wouldn't stay on top, because I had
picked up a little ice, so after one quit I had to descend. I got the right
one lit at about 8,000, say 2500 agl, and right after breaking out VFR.
After landing in Reno, a quick drain of the tip tanks, showed hundreds of
tiny ice crystals. The sample look like one of those "Snow scenes" that you
shake up and watch the white stuff settle. Yes, I had drained all of the
sumps prior to takeoff. No, I didn't find any liquid water, but it was -2C
in the hangar during preflight. The fuel truck checked out as well. Even
after fueling in Tuscon, warm and dry, I still had "snow" in the sample the
next day. While in Reno, we sprayed a little avgas prist into the tank, and
immediately drained out almost a cup of water. After doing this to all
tanks, the mechanic said I was good to go, and I left, with no more
problems.

Prist = Good

Prist before the engine(s) quit=Better

It does appear that "Pucker factor" on the pilots seat can extend your
glide. I think we are not counting all available sources of lift.

Al G

"Al G" wrote in message
...

"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.

I've had the "Twin glider syndrome" in a C-340. South of Klamath Falls,
Or., at FL 220, -30C, The fuel flow for the left one started to twitch,
and whithin 3 minutes, the engine quit. The right one followed about 5
later. Tops were about 20,000, and the 340 wouldn't stay on top, because I
had picked up a little ice, so after one quit I had to descend. I got the
right one lit at about 8,000, say 2500 agl, and right after breaking out
VFR. After landing in Reno, a quick drain of the tip tanks, showed
hundreds of tiny ice crystals. The sample look like one of those "Snow
scenes" that you shake up and watch the white stuff settle. Yes, I had
drained all of the sumps prior to takeoff. No, I didn't find any liquid
water, but it was -2C in the hangar during preflight. The fuel truck
checked out as well. Even after fueling in Tuscon, warm and dry, I still
had "snow" in the sample the next day. While in Reno, we sprayed a little
avgas prist into the tank, and immediately drained out almost a cup of
water. After doing this to all tanks, the mechanic said I was good to go,
and I left, with no more problems.

Prist = Good

Prist before the engine(s) quit=Better

It does appear that "Pucker factor" on the pilots seat can extend your
glide. I think we are not counting all available sources of lift.

Al G

Some of the later model Cessna 340/A, 414/A and 421C had "heated" fuel
manifolds. The manifold (or spider) has a reservoir at the bottom that hot
engine oil flows through to prevent this.

Allen

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.
|

"Allen" wrote in message
t...

"Al G" wrote in message
...

"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.

I've had the "Twin glider syndrome" in a C-340. South of Klamath
Falls, Or., at FL 220, -30C, The fuel flow for the left one started to
twitch, and whithin 3 minutes, the engine quit. The right one followed
about 5 later. Tops were about 20,000, and the 340 wouldn't stay on top,
because I had picked up a little ice, so after one quit I had to descend.
I got the right one lit at about 8,000, say 2500 agl, and right after
breaking out VFR. After landing in Reno, a quick drain of the tip tanks,
showed hundreds of tiny ice crystals. The sample look like one of those
"Snow scenes" that you shake up and watch the white stuff settle. Yes, I
had drained all of the sumps prior to takeoff. No, I didn't find any
liquid water, but it was -2C in the hangar during preflight. The fuel
truck checked out as well. Even after fueling in Tuscon, warm and dry, I
still had "snow" in the sample the next day. While in Reno, we sprayed a
little avgas prist into the tank, and immediately drained out almost a
cup of water. After doing this to all tanks, the mechanic said I was good
to go, and I left, with no more problems.

Prist = Good

Prist before the engine(s) quit=Better

It does appear that "Pucker factor" on the pilots seat can extend your
glide. I think we are not counting all available sources of lift.

Al G

Some of the later model Cessna 340/A, 414/A and 421C had "heated" fuel
manifolds. The manifold (or spider) has a reservoir at the bottom that
hot engine oil flows through to prevent this.

Allen
The mechanic told me that ice crystals had blocked the fuel filter.
Would this heater have helped that?

Al G

"Al G" wrote in message
...

"Allen" wrote in message
t...

"Al G" wrote in message
...

"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.

I've had the "Twin glider syndrome" in a C-340. South of Klamath
Falls, Or., at FL 220, -30C, The fuel flow for the left one started to
twitch, and whithin 3 minutes, the engine quit. The right one followed
about 5 later. Tops were about 20,000, and the 340 wouldn't stay on top,
because I had picked up a little ice, so after one quit I had to
descend. I got the right one lit at about 8,000, say 2500 agl, and right
after breaking out VFR. After landing in Reno, a quick drain of the tip
tanks, showed hundreds of tiny ice crystals. The sample look like one of
those "Snow scenes" that you shake up and watch the white stuff settle.
Yes, I had drained all of the sumps prior to takeoff. No, I didn't find
any liquid water, but it was -2C in the hangar during preflight. The
fuel truck checked out as well. Even after fueling in Tuscon, warm and
dry, I still had "snow" in the sample the next day. While in Reno, we
sprayed a little avgas prist into the tank, and immediately drained out
almost a cup of water. After doing this to all tanks, the mechanic said
I was good to go, and I left, with no more problems.

Prist = Good

Prist before the engine(s) quit=Better

It does appear that "Pucker factor" on the pilots seat can extend your
glide. I think we are not counting all available sources of lift.

Al G

Some of the later model Cessna 340/A, 414/A and 421C had "heated" fuel
manifolds. The manifold (or spider) has a reservoir at the bottom that
hot engine oil flows through to prevent this.

Allen
The mechanic told me that ice crystals had blocked the fuel filter.
Would this heater have helped that?

Al G

No, only the very fine screen that is installed in the fuel manifold itself.
If the main fuel screen was blocked there is no way to prevent that other
than clean fuel and or anti-ice additive.

Allen

Yes, the heaters is often located so that screens and fuel
control units are heated well above the freezing point of
water or the solidification point of JetA.


"Al G" wrote in message
...
|
| "Allen" wrote in message
| t...
|
| "Al G" wrote in message
| ...
|
| "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.
|
| I've had the "Twin glider syndrome" in a C-340.
South of Klamath
| Falls, Or., at FL 220, -30C, The fuel flow for the left
one started to
| twitch, and whithin 3 minutes, the engine quit. The
right one followed
| about 5 later. Tops were about 20,000, and the 340
wouldn't stay on top,
| because I had picked up a little ice, so after one quit
I had to descend.
| I got the right one lit at about 8,000, say 2500 agl,
and right after
| breaking out VFR. After landing in Reno, a quick drain
of the tip tanks,
| showed hundreds of tiny ice crystals. The sample look
like one of those
| "Snow scenes" that you shake up and watch the white
stuff settle. Yes, I
| had drained all of the sumps prior to takeoff. No, I
didn't find any
| liquid water, but it was -2C in the hangar during
preflight. The fuel
| truck checked out as well. Even after fueling in
Tuscon, warm and dry, I
| still had "snow" in the sample the next day. While in
Reno, we sprayed a
| little avgas prist into the tank, and immediately
drained out almost a
| cup of water. After doing this to all tanks, the
mechanic said I was good
| to go, and I left, with no more problems.
|
| Prist = Good
|
| Prist before the engine(s) quit=Better
|
| It does appear that "Pucker factor" on the pilots seat
can extend your
| glide. I think we are not counting all available
sources of lift.
|
| Al G
|
| Some of the later model Cessna 340/A, 414/A and 421C had
"heated" fuel
| manifolds. The manifold (or spider) has a reservoir at
the bottom that
| hot engine oil flows through to prevent this.
|
| Allen
| The mechanic told me that ice crystals had blocked the
fuel filter.
| Would this heater have helped that?
|
| Al G
|
|

"Peter" wrote in message
...

"Al G" wrote

I've had the "Twin glider syndrome" in a C-340. South of Klamath
Falls,
Or., at FL 220, -30C, The fuel flow for the left one started to twitch,
and
whithin 3 minutes, the engine quit. The right one followed about 5 later.
Tops were about 20,000, and the 340 wouldn't stay on top, because I had
picked up a little ice, so after one quit I had to descend. I got the
right
one lit at about 8,000, say 2500 agl, and right after breaking out VFR.
After landing in Reno, a quick drain of the tip tanks, showed hundreds of
tiny ice crystals. The sample look like one of those "Snow scenes" that
you
shake up and watch the white stuff settle. Yes, I had drained all of the
sumps prior to takeoff. No, I didn't find any liquid water, but it was -2C
in the hangar during preflight. The fuel truck checked out as well. Even
after fueling in Tuscon, warm and dry, I still had "snow" in the sample
the
next day. While in Reno, we sprayed a little avgas prist into the tank,
and
immediately drained out almost a cup of water. After doing this to all
tanks, the mechanic said I was good to go, and I left, with no more
problems.

So Prist congealed the water together?

The Prist caused the "Snowflakes" to melt immediately, allowing us to
drain it as water. I think I pulled about 1/2 of a cup from the left tip
tank alone. On the remainder of my trip to Tuscon, I burned off all the
fuel, well except a couple of gallons in the tips. I ran the locker tanks
and the aux tanks dry. I drained all tanks after landing, and found nothing.
I drained the truck before refueling, and drained all the tanks after
refueling, found nothing. I drained all tanks later that night, and the next
morning, nothing. I packed up, flew to Reno, drained the tip tanks, and
found "Snow". Thousands of tiny flakes. Yes, I shook the wings, as much as
you can shake a 340. I have no idea where the water was hiding, or how it
got back into frozen suspension.
During the IFR portion of the glide, I did spot Highway 395 south of
Susanville, along the west side of Honey Lake, on the radar. My last ditch
plan was to do a "Radar" deadstick to the highway. It would have been
absolutely fascinating because without any alternators I hadn't been running
any de-ice gear. I had no forward visibility, and was carrying about 1/2
inch.

Al G