Warming gyros in winter?

flyingcheesehead

flyingcheesehead

Touchdown! Greaser!
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iMooniac
So, I've heard over and over again that it's hard on the gyros to start them up cold in the winter. But, how cold is cold, and how long do they need to warm up?

Could it be potentially worse to start up when they've only been warmed for a short time, as some parts could have warmed up faster than others, maybe causing worse wear than starting them cold?

I think I'm going to be getting a space heater to put in the Mooney if I've still got her when it gets cold. I'd prefer to only turn it on after I get to the hangar, leave it on during preflight (maybe 1/2 hour), and then fire up and go. Is that a good plan, or do things need more time to warm up?
 
flyingcheesehead said:
So, I've heard over and over again that it's hard on the gyros to start them up cold in the winter. But, how cold is cold, and how long do they need to warm up?

Could it be potentially worse to start up when they've only been warmed for a short time, as some parts could have warmed up faster than others, maybe causing worse wear than starting them cold?

I think I'm going to be getting a space heater to put in the Mooney if I've still got her when it gets cold. I'd prefer to only turn it on after I get to the hangar, leave it on during preflight (maybe 1/2 hour), and then fire up and go. Is that a good plan, or do things need more time to warm up?
Click to expand...

Kent, you're a buzzkill. It's still August and beautiful outside! :D

I assume you are talking about a closed, relatively tight hangar? Would you plan on preheating the engine in that environment, and if so, would that engine preheat be enough to keep the gyros, if not warm, at least not frozen?
 
I have a small ceramic space heater that I put on the floor in the cabin when I get to the airport. After30 min for the preflight I dunno if the avionics and instruments are sufficiently warmed up, but that's all I can do.
 
flyingcheesehead said:
So, I've heard over and over again that it's hard on the gyros to start them up cold in the winter. But, how cold is cold, and how long do they need to warm up?

Could it be potentially worse to start up when they've only been warmed for a short time, as some parts could have warmed up faster than others, maybe causing worse wear than starting them cold?

I think I'm going to be getting a space heater to put in the Mooney if I've still got her when it gets cold. I'd prefer to only turn it on after I get to the hangar, leave it on during preflight (maybe 1/2 hour), and then fire up and go. Is that a good plan, or do things need more time to warm up?
Click to expand...
Pointed behind the panel that should be fine.
 
murphey said:
I have a small ceramic space heater that I put on the floor in the cabin when I get to the airport. After30 min for the preflight I dunno if the avionics and instruments are sufficiently warmed up, but that's all I can do.
Click to expand...

This is what we did in Alaska, except we kept the ceramic heater going all night. It was powered via the Tanis. When we plugged the Tanis in, the outlet for the ceramic heater was automatically energized.

(For the legal eagles: I have no idea about the legality of this set up, but the FAA never seemed to be concerned about it.)
 
I cannot see any mechanical reason for having to warm up a gyro, since the only parts in moving contact are ball bearings and slip rings, and that's true for the KG102, the KI256, and various electric AIs I have been the insides of.
 
peter-h said:
I cannot see any mechanical reason for having to warm up a gyro, since the only parts in moving contact are ball bearings and slip rings, and that's true for the KG102, the KI256, and various electric AIs I have been the insides of.
Click to expand...

The only time I was pretty sure I was going to not survive a flight was because my gyros had frozen and ATC staged me down into severe icing on a no gyro approach. Luckily I had manual turbos and a Travelair that hauled a major load of ice and didn't mind landing at 170 too much. Most gyros are pneumatic not electric.
 
I thought the way to warm gyros was that meat on a stick, rotating radiant heat thing? :)

Mmmm... Gyros... Delicious... ;)
 
denverpilot said:
I thought the way to warm gyros was that meat on a stick, rotating radiant heat thing? :)

Mmmm... Gyros... Delicious... ;)
Click to expand...

Kronos...mmmm. I knew one of the owners years back, had a converted crew boat as his yacht a few docks down and loved working on it, he started out his career working on ships in Greece and was a chain smoker. Everyone thought he'd die of cancer, was cleaning his engine room with MEK and lit up a smoke...BOOM! :eek: That was the end of my free supply of Gyros meat and Baklava.:(
 
Most gyros are pneumatic not electric.
Click to expand...

I have

KI256 - vacuum
RHS AI - Castleberry electric
KG102A - electric
TC - electric

That's 3:1 for electric :)
 
flyingcheesehead said:
So, I've heard over and over again that it's hard on the gyros to start them up cold in the winter. But, how cold is cold, and how long do they need to warm up?

Could it be potentially worse to start up when they've only been warmed for a short time, as some parts could have warmed up faster than others, maybe causing worse wear than starting them cold?

I think I'm going to be getting a space heater to put in the Mooney if I've still got her when it gets cold. I'd prefer to only turn it on after I get to the hangar, leave it on during preflight (maybe 1/2 hour), and then fire up and go. Is that a good plan, or do things need more time to warm up?
Click to expand...

In addition to electric engine preheat, I use a small 300W ceramic heater to heat the entire cabin overnight. It's good for both the pilot and the gyros.

Ryan
 
When I was new to flying, I would not preheat and on the mornings when the temp was below zero there was some pretty strange sounds coming from the gauges (whining and groaning sounds). I had to replace several of them in the following years. About 25 years ago I moved to a south facing hangar and on sunny days the temp inside would be as high as 70 on 20 degree days. Since moving into this hangar I have not had to replace any of the gauges. If you don't have a south facing hangar then preheating is required unless you like spending money.
 
nddons said:
Kent, you're a buzzkill. It's still August and beautiful outside! :D
Click to expand...

Just thinking ahead. ;) I'm gonna drop a few benjamins on a Reiff preheater if the plane isn't sold by November or so... Or whenever the temps start dipping below 40 on a regular basis.

I assume you are talking about a closed, relatively tight hangar? Would you plan on preheating the engine in that environment, and if so, would that engine preheat be enough to keep the gyros, if not warm, at least not frozen?
Click to expand...

Yep, one of the newer hangars at Timmerman. Not sure when they were built, but they were there 10 years ago at least. It'll be on a Reiff preheater with both oil and cylinder heaters, which keeps the engine compartment nice and toasty but I don't know that it does anything for the cabin. I also don't know what "enough" is, which is part of why I posted.

murphey said:
I have a small ceramic space heater that I put on the floor in the cabin when I get to the airport. After30 min for the preflight I dunno if the avionics and instruments are sufficiently warmed up, but that's all I can do.
Click to expand...

Have you had to replace any gyros earlier than expected?

n12365 said:
In addition to electric engine preheat, I use a small 300W ceramic heater to heat the entire cabin overnight. It's good for both the pilot and the gyros.
Click to expand...

How long does it take to get the cabin warmed up? Does it really need to be overnight? I'd rather not leave the heater on inside the plane when I'm not there.

Garthur said:
When I was new to flying, I would not preheat and on the mornings when the temp was below zero there was some pretty strange sounds coming from the gauges (whining and groaning sounds). I had to replace several of them in the following years. About 25 years ago I moved to a south facing hangar and on sunny days the temp inside would be as high as 70 on 20 degree days. Since moving into this hangar I have not had to replace any of the gauges. If you don't have a south facing hangar then preheating is required unless you like spending money.
Click to expand...

Hangar faces west. I'm just trying to find out how warm things need to be and for how long. If a small heater for 30 min is enough, that'd be excellent. If not, well, I'll need to figure out a better solution.
 
flyingcheesehead said:
How long does it take to get the cabin warmed up? Does it really need to be overnight? I'd rather not leave the heater on inside the plane when I'm not there.
Click to expand...

I have no idea how long it takes, I always let it run overnight. I also run a Reiff preheater that draws 300 watts. Between the two of them I am drawing 600 watts and the plane is warmed up by the next morning. I am not that worried about leaving it running when I am not there. I have used electric preheat overnight for several winters and have never had a problem.

Ryan
 
'Spearment time! Put your heater in the cabin, and see how long it takes to heat soak the metal to about 50-60 degrees. But you should start your experiment at a temp close to the lows that you would expect in winter.

I would think that a ceramic heater "blowing" behind the panel for about 30 min, to an hour would do the job.
 
Aww c'mon. Kent's finished with Engineering school.

He can calculate how long it will take for the heat transfer with all the metal, air, and accurately correct for air currents and rising air from where the ceramic heater is located on the floor.

Bonus points for calculating the air leak out the door that's open a crack to lest the extension cord in. ;) ;) ;)
 
bluerooster said:
'Spearment time! Put your heater in the cabin, and see how long it takes to heat soak the metal to about 50-60 degrees. But you should start your experiment at a temp close to the lows that you would expect in winter.
Click to expand...

Which metal? It's not easy to measure the temperature of the bearings in a gyro when it's still installed in the panel. ;)

denverpilot said:
Aww c'mon. Kent's finished with Engineering school.

He can calculate how long it will take for the heat transfer with all the metal, air, and accurately correct for air currents and rising air from where the ceramic heater is located on the floor.
Click to expand...

Naah, those are mechanical engineering problems. ;)

Actually, I did have to take Thermodynamics and Heat Transfer to get the EE degree. But that was quite a while ago, and the stuff behind the panel complex enough that I'm sure my calculations would provide a result of dubious worth.
 
flyingcheesehead said:
Which metal? It's not easy to measure the temperature of the bearings in a gyro when it's still installed in the panel. ;)
Click to expand...

Not easy or cheep, but can be done. :wink2:
Either way, I figure that If you can get the cockpit to a comfortable temp and hold it there for a while. Th' gyros will thank you.
 
flyingcheesehead said:
Which metal? It's not easy to measure the temperature of the bearings in a gyro when it's still installed in the panel. ;)
Click to expand...

Really not that tough, if you have the heater behind(in front really;)) the panel, you can get a good representation by pointing a temp gun at the face glass and using that reading.
 
And that will lead to the next question... What is an appropriate temperature?

Ha. There will never be an end to this one.

Fly it, replace insanely cheap gyros as necessary.

You can't throw a rock without hitting a refurbished pile of workable gyros at any shop around here. Enough upgrades to glass of whatever sort, there's a mini-glut of the things.

We have had to replace one, and chose to replace another. Refurbished, neither was over a half an AMU. .3 AMU is common. Most places make their gravy money on throwing in an IFR re-cert.

But... An HSI is another deal... Not cheap to get, not cheap to fix. And I think your uncle's airplane had an HSI, right?
 
flyingcheesehead said:
Which metal? It's not easy to measure the temperature of the bearings in a gyro when it's still installed in the panel
Click to expand...

Damn engineers causing all sorts of damn problems! First they ask a damn question then they deny the damn anwer. Damnitalltohell!

(for the FNGs, I'm an engineer w/three degrees in engineering)
 
Most HSIs the gyro is a remote electric unit so that does complicate matters some.
 
Henning said:
Most HSIs the gyro is a remote electric unit so that does complicate matters some.
Click to expand...

Wow, really? I knew the magnetometer and some other pieces of the HSI were remote, but the gyro? I had no idea. This is the King KI525A on a Mooney Ovation - Where would the gyro be?

And sho'nuff, going back to the documentation, the gyro itself is a separate unit, the KG102A.
 
denverpilot said:
And that will lead to the next question... What is an appropriate temperature?

Ha. There will never be an end to this one.

Fly it, replace insanely cheap gyros as necessary.

You can't throw a rock without hitting a refurbished pile of workable gyros at any shop around here. Enough upgrades to glass of whatever sort, there's a mini-glut of the things.

We have had to replace one, and chose to replace another. Refurbished, neither was over a half an AMU. .3 AMU is common. Most places make their gravy money on throwing in an IFR re-cert.

But... An HSI is another deal... Not cheap to get, not cheap to fix. And I think your uncle's airplane had an HSI, right?
Click to expand...

Yeah - These ain't cheap. Not only does it have an HSI, but it also has a flight director so the AI isn't your run-of-the-mill one either.
 
As an engineer, I would stick a heater in the cabin and see what the temp rise of the panel on a cool night turns out to be vs time. From that, estimate the difference vs hangar temp on a really cold day by some simple thermodynamics relationships. OTOH, why bother with that and I would just wait for a cold day and use a IR thermo gun from Harbor Frieght if it really worried me.:wink2:

Now a scientist would submit a request for a Federal Grant to study the problem, get a one year grant from the Department of Energy, run calculations and experiments for months on specfific heat, mass, airflow circulation, laminar vs turbulent heat transfer and a bunch of other esoteric c*** and still be wrong. :lol:

Cheers
 
denverpilot said:
Fly it until it fails, replace with Aspen. ;) ;) ;)
Click to expand...

Well, Aspen is cheaper than an HSI overhaul I think, so that's what a lot of people are doing. However, I'd rather keep the gyros running as long as I can, preferably until the plane is sold!
 
flyingcheesehead said:
Well, Aspen is cheaper than an HSI overhaul I think, so that's what a lot of people are doing. However, I'd rather keep the gyros running as long as I can, preferably until the plane is sold!
Click to expand...

The engineering answer to that would be, "Sell it quick." ;)

The economics answer to that would be, "It's going to hurt either way. Pull the bandaid off fast or slow, your choice." ;)
 
flyingcheesehead said:
Well, Aspen is cheaper than an HSI overhaul I think, so that's what a lot of people are doing. However, I'd rather keep the gyros running as long as I can, preferably until the plane is sold!
Click to expand...

I thought the Sandel 3500 was a pretty slick high value upgrade if you already had a system like the KFC 225. You may be able to find a used one from someone who upgraded to a 500/600 or Aspen and install it at a resale positive if only that it makes it attractive enough for someone to look. Basically any plane asking over $80k will need to have glass to be able to sell. Basically what we will have is a modernized fleet capable of taking advantage of the technology we have spent billions if not trillions of tax dollars developing. Without you the owners and pilots demanding the equipment to make use of a database we payed for the Space Shuttle to map and develop, all that money spent wasted because people refuse to spend the money to take advantage of it, or using the iPad as only moving map in IMC. Unless everybody uses it, it's useless.
 
Henning said:
I thought the Sandel 3500 was a pretty slick high value upgrade if you already had a system like the KFC 225. You may be able to find a used one from someone who upgraded to a 500/600 or Aspen and install it at a resale positive if only that it makes it attractive enough for someone to look.
Click to expand...

I used an airplane with a Sandel HSI while training for my commercial ticket. It is a very nice piece of equipment, but considering what else is now on the market, I don't think they are worth the price new. Hopefully everyone performing upgrades to full glass panels will flood the market with cheap used equipment.

Ryan
 
n12365 said:
I used an airplane with a Sandel HSI while training for my commercial ticket. It is a very nice piece of equipment, but considering what else is now on the market, I don't think they are worth the price new. Hopefully everyone performing upgrades to full glass panels will flood the market with cheap used equipment.

Ryan
Click to expand...

Exactly, but I'm betting used pullouts will be available at discounted prices like the KMD 150 I pulled.
 
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