fin/wing tanks freezing

Can anyone share some wisdom on using water at high elevations for long durations? How do you know your fin or wing tanks will not freeze? If I am at 18K for 6 hrs in the Sierras, I really don't want my vertical stab splitting open in flight. Has this ever happened? Any guidance would be appreciated.

Matt

On Wednesday, June 5, 2013 8:41:20 AM UTC-7, Matt Herron Jr. wrote:
Can anyone share some wisdom on using water at high elevations for long durations? How do you know your fin or wing tanks will not freeze? If I am at 18K for 6 hrs in the Sierras, I really don't want my vertical stab splitting open in flight. Has this ever happened? Any guidance would be appreciated.



Matt

I know in the Duo Discus I used to own (part of) the OAT gage was a required instrument just for this reason. It will take a long time for a wing tank, or even a fin tank to freeze. But we did have an incident where a dribbling leak from the fin tank collected in the rudder counterbalance and froze, freezing the rudder solid. This was on a day when the return from Mt. Whitney to Truckee was a no-turn romp at 17,999 ft. It did finally unfreeze as the Duo descended on final. I don't know of anyone who has had a fin tank freeze.

Am 05.06.2013 17:41, Matt Herron Jr. wrote:
Can anyone share some wisdom on using water at high elevations for long durations? How do you know your fin or wing tanks will not freeze? If I am at 18K for 6 hrs in the Sierras, I really don't want my vertical stab splitting open in flight. Has this ever happened? Any guidance would be appreciated.

Matt


They will freeze. Depending on the layout of the tanks, it may do damage
to the tank or wing structure.

If you fly in air mass below freezing point, either
- do not use water ballast
- or add the appropriate amount of antifreeze to the water.

If possible, you can land with the ballast water and then recollect the
antifreeze mixture. I know of several pilots that have done it that way.

--
Peter Scholz
ASW24 JE

I fly a Ventus C with integral tanks (no Bags) any issues with antifreeze and carbon/fiberglass tanks? What would be the recommended amount? Sounds like an environmental hazard to dump, and I certainly dont want to land wet unless I have to.

I have had issues with the Ventus fully loaded with water where the flaps seem to stick a bit. Not sure if it was a freezing leak or what, but was a little scary. Frozen rudder must not have been too fun.

Matt

It is folly to fly at high altitudes with water ballast on board. It is a
requirement to have an outside air temp gauge if your sailplane has water
tanks fitted (even if they are never used). I am amazed that this question
has even been posted.
cb



At 16:23 05 June 2013, Matt Herron Jr. wrote:
I fly a Ventus C with integral tanks (no Bags) any issues with antifreeze
and carbon/fiberglass tanks? What would be the recommended amount?
Sounds
like an environmental hazard to dump, and I certainly dont want to land
wet
unless I have to.

I have had issues with the Ventus fully loaded with water where the flaps
seem to stick a bit. Not sure if it was a freezing leak or what, but was
a
little scary. Frozen rudder must not have been too fun.

Matt

In the Sierra, we fly every day at high altitudes with water ballast on board. Literally 10s of thousands of flights. 18,000 feet is common, 24,000 not unusual, OAT of around 20 F is normal. I have never heard of anyone that filled his tanks with antifreeze. Routinely landing with full tanks would be a far greater hazard. I suppose if you were contemplating a dawn-to-dusk record winter wave flight, it might be worth considering.

But perhaps we are all guilty of folly.

On Wednesday, June 5, 2013 9:51:04 AM UTC-7, Croft Brown wrote:
....... I am amazed that this question has even been posted......

cb



You could focus on coaching instead of deriding a fella for asking a genuine question.





At 16:23 05 June 2013, Matt Herron Jr. wrote:

I fly a Ventus C with integral tanks (no Bags) any issues with antifreeze

and carbon/fiberglass tanks? What would be the recommended amount?

Sounds

like an environmental hazard to dump, and I certainly dont want to land

wet

unless I have to.



I have had issues with the Ventus fully loaded with water where the flaps

seem to stick a bit. Not sure if it was a freezing leak or what, but was

a

little scary. Frozen rudder must not have been too fun.



Matt

Of course your right. We must focus on coaching. Read the flight manual
section on water ballast.
cb




At 13:32 06 June 2013, TravisBrown73 wrote:
On Wednesday, June 5, 2013 9:51:04 AM UTC-7, Croft Brown wrote:
....... I am amazed that this question has even been posted......

cb



You could focus on coaching instead of deriding a fella for asking a
genuine question.





At 16:23 05 June 2013, Matt Herron Jr. wrote:

I fly a Ventus C with integral tanks (no Bags) any issues with
antifreeze

and carbon/fiberglass tanks? What would be the recommended amount?

Sounds

like an environmental hazard to dump, and I certainly dont want to
land

wet

unless I have to.



I have had issues with the Ventus fully loaded with water where the
flaps

seem to stick a bit. Not sure if it was a freezing leak or what, but
was

a

little scary. Frozen rudder must not have been too fun.



Matt

On Jun 5, 9:23*am, "Matt Herron Jr." wrote:
I fly a Ventus C with integral tanks (no Bags) any issues with antifreeze and carbon/fiberglass tanks? *What would be the recommended amount? *Sounds like an environmental hazard to dump, and I certainly dont want to land wet unless I have to.

I have had issues with the Ventus fully loaded with water where the flaps seem to stick a bit. *Not sure if it was a freezing leak or what, but was a little scary. *Frozen rudder must not have been too fun.

Matt

The factory probably has a recommended antifreeze agent; if so, use
that. In the absence of such a recommendation, I would probably use
propylene glycol-based antifreeze intended for winterizing RVs and
cabins; it is pretty safe stuff. I would be very wary about using
ethylene glycol antifreeze unless I knew for certain that the ballast
system bags, tanks, linings, plumbing, seals, and valves were all
compatible with it. And even then I probably wouldn't use it for
environmental reasons.

Thanks, Bob K.

even if it doesnt freeze in the tanks, it may well when dumped. I
know of a case of this in the uk, the ice buildup at the base of the
fin apparently made things interesting.

Anyone understand the the issues of high altitude limiting speeds
and a ballasted glider?

At 15:41 05 June 2013, Matt Herron Jr. wrote:
Can anyone share some wisdom on using water at high elevations
for long
dur=
ations? How do you know your fin or wing tanks will not freeze?
If I am
a=
t 18K for 6 hrs in the Sierras, I really don't want my vertical stab
splitt=
ing open in flight. Has this ever happened? Any guidance would
be
apprecia=
ted.

Matt