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Winter Ops - Pre Heat

Posted: Fri Dec 11, 2020 4:26 pm
by jump_154
First winter as an aircraft owner - looking for advice on using pre-heat (Tanis) heater.

Grumann AA-5 in an unheated hangar. Has Tanis heater installed, hydro available and that's it.

Have always flown flight-school aircraft, that either lived in heated hangars, or seemed to be permanently plugged in.

Spoke to my AME, who advised against leaving plugged in all the time as that is 1) a fire hazard and 2) leads to condensation and corrosion.

Trying to find out more, have seen opinions that temperature cycles (without flying) will lead to corrosion, which makes sense to me - but leaving heat on all the time is OK - any thoughts on that? On one hand would be like summer - engine stays warm, but on the other hand all it takes is one colder component and I can see how condensation can form.

other option is to plug in before each flight - but that means an extra trip to the airport 3-5 hours before flight, and at 1 hour round trip that is not desirable.

So i'm looking into a smart switch combined with a mobile wifi hub , but that is a medium term solution. (Aircraft Spruce has text activate controllers, but they are very expensive and out of stock, and might not work in southern ontario)

So any opinions on:

1) Is it OK to leave plugged in all time time the a/c is on the ground (assume aircraft flies weekly, sometimes once a fortnight)

2) Any experience with smart switch/wifi hub solutions.

Re: Winter Ops - Pre Heat

Posted: Fri Dec 11, 2020 4:39 pm
by Colonel
1) run a multi-viscosity oil. I prefer cat-piss x/c 20w50 with 10% Camguard
instead of that shitty, expensive 15w50 which makes your engine leak. Either
way you need something thin to avoid metal on metal at startup, and you need
something with a low enough pour point that it won't congeal in the oil cooler.

2) batter tender jr (750mA) on the battery. Put it on every time you walk
away from the airplane. Do not let it discharge. In addition to permanently
weakening it with sulfation, the lead-acid can freeze and crack and piss acid
all over the inside of your airplane. Seen that lots of times.

3) get a new AME. Or at least stop listening to the one you have. Condensation
occurs on a surface which is COOLER than the dew point of the atmosphere. I
am not making this up - look it up for yourself. The dew point in the winter is
extremely low - check any METAR.

Image

That is because cold air cannot hold moisture in suspension. I had a good friend
with a Lycoming - SuperCub on skies - that plugged his engine in every time he
landed. Heater ran all the time. Engine never cooled off, was always WARMER
than the dew point. No condensation. No corrosion.

I know people think I'm the stupidest fucking person to ever walk the earth, but
Jesus Christ. You're getting cold wx ops advice from someone who lives where
there is no snow. Think about that.

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Re: Winter Ops - Pre Heat

Posted: Fri Dec 11, 2020 8:33 pm
by John Swallow
In addition to the info provided by Andy:

"If a pilot flies about once a week or more ... and has a heater that heats the entire engine, he or she can leave the heater plugged in while their aircraft is covered in a hangar. Otherwise, the preheater should be started a few hours before they intend to fly."

From:

https://www.aviationpros.com/home/artic ... l-the-time


I’m lucky: I have a hangar with thermostat-controlled gas heat…

Re: Winter Ops - Pre Heat

Posted: Fri Dec 11, 2020 9:24 pm
by jump_154
Thanks for the inputs! Couple of questions:

1) "Condensation occurs on a surface which is COOLER than the dew point of the atmosphere." Understood - but are we not worried about the atmosphere inside the engine? i.e. we heat up the oil, which has some moisture in - does that raise the dewpoint of the air inside the engine enough to condense on a cooler part of the engine? Or is all the moisture that causes corrosion in an engine left for a long time coming from the ambient atmosphere anyway?

I can see how a heating and cooling cycle (say, you put a thermostat on the Tanis heater to come on when ambient is below freezing) can cause problems - but by understanding if I jut leave it on (hot) it should be OK (as you say).

2) Battery Tender -- I have a Concorde battery, and the literature says the battery tender is not compatible with these batteries due to "in some circumstances" can overvoltage the battery. (and of course, there is a very expensive alternative). The flip side is, will leaving it not charging potentially cause more damage than the battery tender could possibly cause?

Cheers!

Re: Winter Ops - Pre Heat

Posted: Fri Dec 11, 2020 11:10 pm
by Colonel
There are two different kinds of chargers:

1) constant current, and
2) constant voltage (not really constant, but ...)

The cheapest chargers - say $10 - will provide a constant amp. Open loop.
These chargers, left long enough, will damage the battery with over-voltage.

The second kind of charger "constant voltage" is closed loop and varies
it's current output for the voltage it sees. These are $40 and one brand is
called the "Battery Tender" and I use them on everything - motorcycles,
airplanes, cars, you name it.

Concorde and Gill batteries are shit. You pay big dollars for a really terrible
product. They are either lead-acid (shudder) or AGM. All of them benefit
tremendously from a Battery Tender Jr, which provides a max 3/4 of an amp
and WILL NOT OVERCHARGE your lead-acid/AGM battery.

There are many other "smart" charger brands, as well. Read their literature
and know that your lead-acid/AGM battery is permanently damaged by sulfation
when the voltage drops. You will enormously extend the life of it, with a
smart charger.

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Re: Winter Ops - Pre Heat

Posted: Fri Dec 11, 2020 11:17 pm
by Colonel
Two things you need to get:

1) Camguard (put it in the oil: 5% is good, 10% is better)
2) Battery Tender Jr (put it on the battery at the end of every flight)

I have been maintaining and flying more bizarre aircraft than you
can possibly imagine, during the last half-century. I know the above
isn't much to show for that, but I know those 2 things are true.

Image

Here'a a Hail Mary:

3) absolute minimum RPM after start for the first minute. I know a
guy with a PhD, works for CSIS or some sh1t like that, likes to hammer
on 1700 RPM right after start. I think he hates his Lycoming.

Contrast the government PhD with the following engine data from my
son starting an AEIO-540-D4A5 in a Pitts S-2B:

Image

See the difference? Now, most Canadians probably think my son is
a moron compared to them, but he had his ICAS card at 19, and his
undergrad engineering degree at 22.

Image

Re: Winter Ops - Pre Heat

Posted: Sat Dec 12, 2020 6:24 am
by Scudrunner
Dam I really should be paying The Colonel money to be provide this advice.

I see my next YouTube promo

Movie tone voice guy

“Some forums banned him
Governments censored him
One man tells it like it is

Join the Colonel on Scudrunners.com”

Re: Winter Ops - Pre Heat

Posted: Sat Dec 12, 2020 3:21 pm
by Colonel
Line maintenance is like plumbing. There's a lot to it, but you can learn it all in one day:

1) poop runs downhill
2) cold is on the right
3) payday is on Friday

Re: Winter Ops - Pre Heat

Posted: Sat Dec 12, 2020 4:01 pm
by JW Scud
Scudrunner wrote:
Sat Dec 12, 2020 6:24 am
“Some forums banned him
Governments censored him
One man tells it like it is

Join the Colonel on Scudrunners.com”
I like that. It sounds like the opening for a most popular TV show ever.

Posters harassed him, Forums banned him, Bureaucrats attacked him, Governments censored him.

His blood defies gravity at the bottom of a loop, His hair remains in place no matter the negative load, the air parts for His airplane like the Red Sea.

"I don't always pull high G's in a biplane - but when I do, it is in a Pitts"

He is - the most interesting aerobatic pilot in the world.


Re: Winter Ops - Pre Heat

Posted: Sat Dec 12, 2020 4:41 pm
by Scudrunner
Those are gold. Great Marketing job I think I should hire them for this Website. I hope they take bad cheques. :|