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COLD weather operations

A

andyrv

Well Known Member
I may need to do a round trip Monday from Dallas to KC. Looks like it will be 20F here when I leave (engine will be heated inside hanger). Will be 15F or so in KC for a refuel and turn around. Any issues or recommendations from those who fly in this type of weather on purpose?

Thanks,
Andy
 
You will want to block off your oil cooler. I completely covered the core on my 7A with 0-360 (cooler was mounted on the rear of the baffles). That's about all I did for that type of temperature. I was too much a wus for colder flying. I used to fly my Cherokee down to Zero doing the same thing. One other thing. Make sure the draft tube has a blowcock and is heated by the exhaust in really cold air, lest yee blow the front seal. Did that on the Cherokee after a cold flight in damp air. After I landed, it froze up, and I blew out the seal when I throttled up to taxi off the runway.

Have fun,

Roberta
 
Dress warm and turn on the heater :rolleyes:.

'RV' heaters are usually 'ok' down to about 20F.

Of course you already know that.
 
that's warm weather!!

That should be a comfy warm flight, at least by Iowa standards!

See my post about the plug in $17 seat heater - a warm tush makes a big difference. Also, go to walmart and buy a pair of $0.94 fabric gloves. They are thin enough to fly in / tune radios, etc. but do keep your hands warm.

The biggest problem in real cold Wx is that your breath will frost up on the inside of the windscreen. Usually happens just before and after engine start, when there isn't any heat yet. If your RV doesn't have defrost, you can wipe it off with a soft cloth (or a cheap walmart glove).

Also, lean your engine to get more EGT (=more heat)

dave
 
Enjoy the flight! I've made that one a couple of times. Monday is suppose to be a high of zero, like Robeta says block off the oil cooler. Don't worry about oil temps under 220F.

Where in K.C. are you landing?
 
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why do RVs have weak heat?

rv6rick said:
'RV' heaters are usually 'ok' down to about 20F.
Click to expand...
Sorry for the thread hijack - but why is that? The mighty Skipper has a single heat muff wrapped around the muffler, plumbed with scat tubing. Pretty conventional looking setup.

It gets astonishingly hot - so much so that in the summer you have to tape it off inside because the air leaking around the doors is so hot. In fact, if you reach under the panel and touch the distribution box in summer you could get burned.

In winter, I've flown it down to 0F and it is OK at that leve, comfy at 10F or above.

And that is with an O-235 putting out less power (and presumably less heat into the exhaust stack).

What is the difference? Is it that the heat muff is wrapped around the muffler, not just a section of pipe? Does anyone have an RV with the heater around the muffler?
 
20F? Thats warm!

A few suggestions. For 20F I would block off 2/3 of oil cooler. Don't block the entire thing off especially if you plan a long climb. Depends on how cool your oil typically runs.

Wear small thin gloves while flying. A thicker pair for pre-flights.

When draining fuel, ensure o-rings don't continue to drip.

A scarf is always nice to guard against those canopy drafts you never knew you had now thats it cold outside.

Sounds like you got the pre-heat taken care of. Fuel up before you put the airplane away. That way the next day when its all warm you can start and go rather than gas up.

Best piece of advise I can give is dress REALLY warm so that you preform that same kind of preflight that you would normally do in warmer weather.

Fly away and enjoy the higher than normal climb rates!

Steve
7A Flying
Nova Scotia, Canada
 
Thermal socks. I fly without shoes so add another pair of socks after you get in the plane.

Have blankets of some sort handy if you need something to stay warm.

I take along toe warmer packs just in case.

If your vents are drafty maybe some tape to cover them (inside).
 
Gas caps

If you should be unfortunate enough to have used fuel lube (EZ Turn) on your gas caps, you may not be able to remove them in KC (high temp forecast around 20 for Monday). That stuff is really problematic for caps. If so, try to borrow some that don't have any in them.

The question about why RV's are a little tough to heat has a lot to do with speed. Flying slow, 100 kias for example, makes them much, much warmer than at 160 kias. Lots of places that cold air wants to come in.

20F with sun is remarkably warmer than if cloudy.
 
IowaRV9Dreamer said:
Sorry for the thread hijack - but why is that? The mighty Skipper has a single heat muff wrapped around the muffler, plumbed with scat tubing. Pretty conventional looking setup.

It gets astonishingly hot - so much so that in the summer you have to tape it off inside because the air leaking around the doors is so hot. In fact, if you reach under the panel and touch the distribution box in summer you could get burned.

In winter, I've flown it down to 0F and it is OK at that leve, comfy at 10F or above.

And that is with an O-235 putting out less power (and presumably less heat into the exhaust stack).

What is the difference? Is it that the heat muff is wrapped around the muffler, not just a section of pipe? Does anyone have an RV with the heater around the muffler?
Click to expand...

You nailed it. A muffler absorbs considerable heat which can be transferred to the cabin. The mufflerless "straight pipes" on all the RV's except the -10 are very efficient and just don't heat up like a restrictive muffler. By the time you get out of an RV following a flight you can touch the tailpipes without getting burned!
 
You can fly below 20, but that number seems to be where the "nice" warmth stop and you start needing extra layers. RV10 excluded of course (you can fly most of the 10's in tshirts at much colder weather if they are well built....but most have mufflers too)!

I typically make 15 degrees the point where it takes extra prep for clothes, etc.. I also use a fancy "steinair" winterization kit consisting of strips of duct tape over the air inlets too. I also usually block off a little bit of the air for the heat muff too so there is less flow and more heat. On a cloudy day in a descent it gets might cold mighty fast! I've flown the RV down to and below zero, but it's just not fun anymore when it's that cold! :)

Cheers,
Stein
 
Stein reminded me of something. Bring a scarf. The most uncomfortable thing is to have a draft on your neck.

Maybe this is why open cockpit drivers had silk scarfs? Maybe, but they used them mostly to clean oil off their goggles!
 
heat

I have an RV-4 with 0-320 and vetterman exhaust. I replaced the stock heater with one from Robbins Wings. It wraps two of the straight pipes as opposed to just one pipe like the old one. I can fly in a tee shirt down to single digit weather. In fact, I remove it during the summer to prevent any heat leaking in when I least need it. My Mooney did not heat the cabin as well in similar weather.
Also, as a side note, Robbins makes parts that can best be described as "art". I've NEVER come across anything in aviation with such attention to detail.
Preheat if able, always warm the motor up. Thick cold oil blows seals. Block some of the oil cooler as needed to get the temps up.
Be safe, have a ball,
Dennis
 
Cold weather ops?

20 degrees in Dallas this morning!

What are your limitations for a cold start on a Lycoming?

Of course there are hangars, heating devices, etc. but what is your lowest acceptable temperature for a cold start?

FWIW: I am using the multiviscosity Phillips oil
 
I preheat anything below 40F.

Set a quart of your oil outside and then try to pour it what in is 20F. Pretty amazing.
 
Dmadd said:
...one from Robbins Wings. It wraps two of the straight pipes as opposed to just one pipe like the old one.
Click to expand...
Hi Dennis - I'm a bit confused. Does it wrap 2 different pipe in parallel, or in series? Can you post a picture? This sounds great.
thanks,
 
Actually I went flying the other day at 25F, I even added oil (Exxon 20-50) the oil pored fine, the engine started fine, the oil pressure came up fine and well in limits, the engine and oil warmed up and I had a great time! Lycoming calls cold weather operations, suggesting pre heating at and below 10F.

Russ
 
HEAT

My 9A might be the only one flying with mufflers. While under construction I was going through ebay and found a set of exhaust pipes for a RV 7 or 9. I called the seller who was a manufacture of certified exhausts as well and asked about these pipes. It turns out they went into the experimental market as there is less competition. They told me if I didn't win the pipes on ebay they would build me another set. But I should not delay as Vans gave them a order for the pipes for the RV 10. I have since heard that Veterman and this company are the ones making the 10 exhaust. FWIW.
By the way I have NO problem keeping warm in cold weather my heat muff is around the muffler.
 
Dave,
Go here for pictures and info.
robbinswings.com
On my 4, the two exhaust pipes on the right side go to the back together. The heat muff wraps them both. Uses less space and scat tube than the old design, and provides MUCH more heat.
The workmanship, design and welding are unmatched.

Good luck
Dennis



IowaRV9Dreamer said:
Hi Dennis - I'm a bit confused. Does it wrap 2 different pipe in parallel, or in series? Can you post a picture? This sounds great.
thanks,
Click to expand...
 
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seals

I'm curious. If you do blow the front seal, what's involved in replacing it?

Also, how do you guys block off a portion of your oil cooler?

Steve
 
Steve,
Aluminum tape from the aviation section of home despot. Cover up some of the oil cooler. Fly it, then either add or remove tape a necessary. (mine is completely covered) Louisville, KY is in the 20's F
As for the front seal...remove prop, clean up the mess. Learn to cuss, call your engine guy. Work some overtime to pay him.

Dennis

s_tones said:
I'm curious. If you do blow the front seal, what's involved in replacing it?

Also, how do you guys block off a portion of your oil cooler?

Steve
Click to expand...
 
s_tones said:
I'm curious. If you do blow the front seal, what's involved in replacing it?

Steve
Click to expand...

Short version is the seal gets stretched over the prop flange and inserted into the case seal cavity. Only takes a few minutes for a knowledgeable tech once the prop is removed.
 
The large "double pipe" heat muff will only work on the 4's, or on some of the 4 pipe straight systems...not the normal crossover systems on 6,7,8,9's. Don't go ordering that double muff unless you have an RV4 exhaust or a similar system that it'll work on.

Blown seals aren't that common unless you don't pre-heat and run the oil pressure climbs too fast. Also, replacing the front seal is relatively quick on it's own, it's just the cleaning and prep time that takes a good deal of work. The front seals are availble in single or cut, but usually it just gets stretched of the crank. I replaced one in my 6 a couple years ago, and it wasn't that huge of a deal. Took me longer to clean out the old mastic and prep the new than it did to actually change the seal.

Lastly, at some point blocking off the oil cooler does you no good and you have to start blocking off the air inlets and outlets as well....which is where that fancy duct tape or metal tape comes in handy!

Cheers,
Stein
 
blocking the cold air

What is the current advice for doing this on the RV-4? Block inlet or out let first? And... how?


Lastly, at some point blocking off the oil cooler does you no good and you have to start blocking off the air inlets and outlets as well....which is where that fancy duct tape or metal tape comes in handy!

Cheers,
Stein
 
cold weather

20 F is within the limits suggested by lycoming but I preper to pre-heat at any temps below freezing. Using multigrade oil helps, if it drips off the dipstick you will probably get oil pressure almost immediatly after start-up. Avoid over priming as the excess gas will wash the thin film of oil off the cylinder walls and is a fire hazard. Try to keep the rmp below 1000 for the first minute (I believe your engine has tapered cylinders and you don't want the pistons scrunching the rings up into the narrow part untill they've had time to expand a bit). I find it helpfull to have the primer out a bit while starting so you can give it a bit of a shot of prime when it starts to die a second or so after it starts. Have a clean soft cloth available to clear the canopy.
Chuck Ross RV4 Canada (we had a formation yesterday at -13 degrees F)
 
Hi Chuck....

....more of a concern is getting the cam and lifters/cylinder barrels lubed properly early in the start process. The thick oil just doesn't "splash" well enough and can cause premature cam/lobe wear. That's the reason I really like my Reiff preheater. For somewhere around $200, it's a bargain. The oil sump is heated and that is passed on to the cylinders and your oil can be around 90 degrees after an overnight heat.

We installed one of the Reiff sump heater units on a friend's Cirrus....he almost ran the battery dead during 26 degree temps, trying to start that big IO-550 Conti.....problems solved.

Regards,
 
I don't go to the airport in cold weather without wearing my L.L.Bean FLANNEL lined, relaxed fit jeans.. Notice I included "FLANNEL" in the above description. I try not to fly while wearing anything labeled FLEECE, even in warmer weather. FLEECE is another name for POLYESTER. Imagine melted plastic adhering to your skin; that's what happens to burn victims when polyester clothes are worn. FLANNEL and Denim are cotton...not fireproof, but cotton and wool are much better at resisting burn damage to the skin than polyester.

I have two pair of these jeans, and I started wearing these about 8 years ago. I know at least two RV pilots I recommended them to who took my advice and now say they are "required equipment" for flying in cold weather.

I also put on my SMART WOOL socks before going to the airport. If your feet ain't warm, your whole body ain't warm. And modern wool blends don't itch.

In fact right now in my office I have the above two suggested cold weather clothing choices on. I feel like I need to go flying!

Don
 
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Low temps

I use 2* 50W automotive sump heaters on my FF sump..Now it doesn't get too cold in the Willamette valley but it did get to the teens the other day..When I went flying the oil temps were still 56F at start..Not bad.

I keep cowl plugs in my Sam James cowl in tha hangar.

The cool thing about the 50W heaters is you don't need a thermostat as it only heats the oil to about 30 to 40F above ambient.

They are CHEAP too..like around $30 for the pair from memory.

Frank
 
sealing canopy

& other points of leaking air i think would help.

How can someone seal a slider canopy?
Are any other points that a typical RV leaks air and if you seal them you will have better heating?


Just ideas i found searching these forums.
 
SX-ALY said:
& other points of leaking air i think would help.

How can someone seal a slider canopy?
Are any other points that a typical RV leaks air and if you seal them you will have better heating?


Just ideas i found searching these forums.
Click to expand...

You seal the side skirts of the slider by dropping a piece of foam pipe insulation into the void between the canopy tracks and the canopy skirts. Works very well. You can use weatherstripping to seal the aft skirt, and then you need to put boots on the push-pull tubes for the ailerons where they exit the fuselage.

At that point, you have a pretty tight cockpit. The only things left are vent leaks, which can be sealed with creative application of RTV and leaks around the baggage compartment aft panel. Those can be sealed with a little more thick weatherstripping.

Like others in this thread, I find that with only one cabin heater, a well sealed airplane is comfortable down to well below freezing temperatures. On a sunny day, the cabin is reasonably comfortable down to about 0F, which is pretty darned cold..
 
Russ McCutcheon said:
Actually I went flying the other day at 25F, I even added oil (Exxon 20-50) the oil pored fine, the engine started fine, the oil pressure came up fine and well in limits, the engine and oil warmed up and I had a great time! Lycoming calls cold weather operations, suggesting pre heating at and below 10F.

Russ
Click to expand...

Russ, there is an interesting article in this month's EAA Sport Aviation magazine, Page #82. It talks about why not preheating near freezing temps is not good for an air cooled aircraft engine. It's not about oil flow, it is about aluminum shrinking (2X steel) in cold temps, main bearing wear, cylinder wear, ect. IMHO if you have access to a preheater you should use it under 40F. Interesting article.
 
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Liquid cooled baby with EFI, oil thermostat and multigrade oil. Starts the same hot or cold, got lots of cabin heat and the oil always stays above 80C.

You still need something to cover the back of your neck with the slider but everything else is toasty.:)
 
Electric clothing

I'm surprised nobody has mentioned electric clothing motorcyclists wear in the winter. There are insoles, pants, vests, jackets, and gloves, thermostats, etc. from the likes of Gerbing and Widder. I mention these since they are what I was looking at when I used to make XC m/c rides.
 
RV heat

I just had the pleasure of ferrying a friends RV6a back from International Falls where the temperatures was -26F. My personal RV has the small single vans heat muff and it is not good too far below freezing. I was pleasantly surprised to find this aircraft had two larger muffs (looks like spruce) and provided enough heat the clear the windshield before takeoff and way too much heat for the three hours back to Iowa. Cockpit stayed in the 70s all the way back and I had to open the eyeball vents! I was shocked, but think I will upgrade to a larger muff while my plane is down for the condition inspection.
 
cold weather ops

Okay, it's still cold, so I hope this is still relevant.
apologies for not being very familiar with owning a Lyc with oil cooler, but in a lot of these posts, there are references to blocking it off, which I dutifully have.
...but doesn't the Vernatherm keep the oil in the engine until it exceeds about 185 degrees anyway????...thus, no chance of 'overcooling' the oil?
LIkewise on startup, there are stories and even photos of oil coolers bursting....but why would there be any pressure on it at all, until the engine warmed up to 185?
I had to taxi around for 20 minutes to see 160 degrees, when it was only a few degrees above freezing.
Hope some light can be shed on this.....appreciated.
 
Oil Cooler

The oil is recirculated through the filter regardless of temps. Then it goes to the vernatherm. The VT will route the oil back to the engine if its below 180, through the oil cooler if its above 180.

The VT does let a small amount of oil go through the cooler below 180 mainly to keep oil from congealing and plugging up the oil cooler. If the oil cooler gets plugged, it can burst if it gets plugged for any reason, so that's why a bit still goes through it. Blocking off the airflow in cold weather stops that small oil flow from getting any appreciable cooling so it can be helpful in real cold Wx - not like the kind we get in Phoenix but the kind you get up there ;)


flyboy1963 said:
Okay, it's still cold, so I hope this is still relevant.
apologies for not being very familiar with owning a Lyc with oil cooler, but in a lot of these posts, there are references to blocking it off, which I dutifully have.
...but doesn't the Vernatherm keep the oil in the engine until it exceeds about 185 degrees anyway????...thus, no chance of 'overcooling' the oil?
LIkewise on startup, there are stories and even photos of oil coolers bursting....but why would there be any pressure on it at all, until the engine warmed up to 185?
I had to taxi around for 20 minutes to see 160 degrees, when it was only a few degrees above freezing.
Hope some light can be shed on this.....appreciated.
Click to expand...
 
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