Exercising a plane

Jeanie

Jeanie

Pattern Altitude
Joined
Dec 15, 2008
Messages
2,239
Location
Alpine, TX
Display Name
Display name:
Jeanie
Its not good for an aircraft to sit... They all say.

So, how often should a Cessna 182 be flown to keep it in good condition?
 
Jeanie said:
Its not good for an aircraft to sit... They all say.

So, how often should a Cessna 182 be flown to keep it in good condition?
Click to expand...

I like to fly my 172 every 2 weeks... hopefully for an hour at least to get the oil temperature up. I've let it sit a little longer on business trips, and haven't noticed any acting up.
 
I think it would depend somewhat on where your plane is located. Wet humid climates might need it more often, as a good part of the exercise is to get the moisture out of the oil and prevent corrosion. I try to fly once a week, but if I miss a week, I don't worry about it and I have been down for up to five weeks for maintenance. It is pretty dry here in Sacramento, though.
 
The worst thing you can do to an airplane engine is let it sit. As others have noted, the key is getting the engine up to operating temperature...running it on the ground is not the answer. In "Key Reprints from the Lycoming Flyer," Lycoming says (in part) "Pilots have asked 'What really happens to an engine when it is flown only one or two times a month?' An aircraft flown this infrequently tends to accumulate rust and corrosion internally."

Later, they say that the oil temperature should be brought up to at least 165 degrees and warn against ground operation. You can Google this Lycoming pub.

Bob Gardner
 
At least as far as the engine's concerned, flying enough to get the oil temp above 160-170F for at least 30 minutes at least every week to 10 days. Do that, and everything else should be fine. Don't try doing this on the ground, as you'll overheat the cylinders if you run hard enough/long enough to get the oil that high without flight-regime airflow through the engine compartment.
 
Yep, what they said.

I go at once every 2 weeks as a goal and use CamGuard to help. Reality of my life is that I don't fly every week every more. So, compromise.
 
Hey Ted, I'll take her up every other week for ya:rofl:


I wouldn't mind getting my passenger currency back:lol:
 
Jeanie said:
Its not good for an aircraft to sit... They all say.
Click to expand...
That's what they say, but I would guess that 90% of the planes out there sit for weeks/months at a time.
I'm more familiar with boater habits, but with boats most engines sit for months at a time without any obvious harm, and this is in a marine environment. I wouldn't worry to much about it.
 
For an airplane tied down outside, flying frequently helps the airframe too. Dries out the water that likes to collect in various spots.
 
John221us said:
I think it would depend somewhat on where your plane is located. Wet humid climates might need it more often, as a good part of the exercise is to get the moisture out of the oil and prevent corrosion. I try to fly once a week, but if I miss a week, I don't worry about it and I have been down for up to five weeks for maintenance. It is pretty dry here in Sacramento, though.
Click to expand...

The moisture in the engine comes from combustion byproducts getting past the rings. Like water in the fuel tanks, very little comes from atmospheric moisture.

Short flights are bad. There's more blowby when the engine is colder and more moisture accumulates early in the run, so a short flight can't get the temps up and doesn't have time to get the water out.

Most of my flights are short, but if I had to fly long flights every time I would never fly. Better to fly some and accept the fact that nothing lasts forever.

Dan
 
Dan Thomas said:
The moisture in the engine comes from combustion byproducts getting past the rings. Like water in the fuel tanks, very little comes from atmospheric moisture.

Short flights are bad. There's more blowby when the engine is colder and more moisture accumulates early in the run, so a short flight can't get the temps up and doesn't have time to get the water out.

Most of my flights are short, but if I had to fly long flights every time I would never fly. Better to fly some and accept the fact that nothing lasts forever.

Dan
Click to expand...

Most of my flights are at least an hour. I usually fly somewhere, like the coast, for lunch and to hang out. Sometimes I do a longer xcountry. I log a little over 100 hours per year.
 
Skylane81E said:
Hey Ted, I'll take her up every other week for ya:rofl:


I wouldn't mind getting my passenger currency back:lol:
Click to expand...

Ahh yes, but then comes the deal I made with the previous owner. "You're the only one who flies the plane." :)
 
I try for twice a week, at least once a week for an hour or so.
 
Jeanie said:
Its not good for an aircraft to sit... They all say.

So, how often should a Cessna 182 be flown to keep it in good condition?
Click to expand...

They don't, but they must be put away properly. Which no pilot ever does.
 
I have the original Wakmann 8 day wind up clock in my plane. I love it, it keeps great time and is nostalgic. It's this one:

mMJXTFpGwZcRdBEnVuZ7mWw.jpg


And it also provides a very important bit of data that no digital clock ever could...if it's not running,, then it's been too long since I last flew!
 
Our 182 flies as often as 3-4 hours per week sometimes and as little as 3-4 hours per month, no ill effects so far. ;) I think ideally a plane should fly 1-2 hours per week or more.:D
 
Dan Thomas said:
The moisture in the engine comes from combustion byproducts getting past the rings. Like water in the fuel tanks, very little comes from atmospheric moisture.

Short flights are bad. There's more blowby when the engine is colder and more moisture accumulates early in the run, so a short flight can't get the temps up and doesn't have time to get the water out.

Most of my flights are short, but if I had to fly long flights every time I would never fly. Better to fly some and accept the fact that nothing lasts forever.

Dan
Click to expand...


Here is a little factoid that will win many drinks in a bar if you play it right. One of the by products of burning gasolene is water. Water in the form of water vapor, but water by volume. How much water? For every gallon of gas burned in an internal combustion engine produces 1.2 gallons of water. :eek:

Cheers! :cheers:
 
Ron Levy said:
At least as far as the engine's concerned, flying enough to get the oil temp above 160-170F for at least 30 minutes at least every week to 10 days. Do that, and everything else should be fine. Don't try doing this on the ground, as you'll overheat the cylinders if you run hard enough/long enough to get the oil that high without flight-regime airflow through the engine compartment.
Click to expand...
So, If you run it long enough to get the oil temp up to a point above the boiling point of water, you think that is good enough?

If that is true, and the water does separate from the oil where does it go? Out the breather you think? Does your engine have that much blow by? or does it remain in the engine as steam and then re-condence on the upper portion of the engine, where Lycoming's cam is located?

You stated that idling produces a high engine temps, That may be true, but wouldn't that help getting rid of the water on the long taxi back to the hangar?

Dan says that very little water comes from the atmosphere, so if you fly it like you say, then put it away where does the new water come from?

My best advice to the 182 owner is when you don't fly much use EXION ELETE, and don't worry about that 0-470. It's probably coked up well enough that it will set month after month with no problems.

Lots of misconceptions and old wives tales about engine corrosion.
 
Geico266 said:
Here is a little factoid that will win many drinks in a bar if you play it right. One of the by products of burning gasolene is water. Water in the form of water vapor, but water by volume. How much water? For every gallon of gas burned in an internal combustion engine produces 1.2 gallons of water. :eek:

Cheers! :cheers:
Click to expand...

Really ? and how much of those by products stay in the engine?

I would hate to try to estimate the number of oil changes I done on dry sump engines, and have yet to see any amount of water drain out.

So, where do all those "BY PRODUCTS" go
 
Tom-D said:
Really ? and how much of those by products stay in the engine?

I would hate to try to estimate the number of oil changes I done on dry sump engines, and have yet to see any amount of water drain out.

So, where do all those "BY PRODUCTS" go
Click to expand...

We are talking bar bets here! :rofl: :lol:

How much water will oil hold per gallon? How much water will gas hold per gallon? Unless you know the answer you are just a grease monkey changing oil. :yes:

Only a small portion, but it does go in the engine oil and crankcase none the less. This is why engine oil manufacturers suggest oil temps hit 200f at least once a flight. This boils off most of the water in the oil.

It is a good idea after putting the bird in the hangar to open the oil dip stick and allow the water vapor to escape. ;)
 
Last edited:
Geico266 said:
How much water will oil hold per gallon?

zero, they do not mix

How much water will gas hold per gallon?


zero, they do not mix, buy water will stay in suspension, until the specific gravity causes them to settle out
Unless you know the answer you are just a grease monkey changing oil. :yes:

yep that's me, I just change oil and overhaul when necessary.

Only a small portion, but it does go in the engine oil and crankcase none the less. This is why engine oil manufacturers suggest oil temps hit 200f at least once a flight. This boils off most of the water in the oil.

Water boils at 212f degrees, ??

It is a good idea after putting the bird in the hangar to open the oil dip stick and allow the water vapor to escape. ;)
Click to expand...

And when you see steam what are you doing wrong?
 
Last edited:
Tom-D said:
And when you see steam what are you doing wrong?
Click to expand...

Then you are a grease monkey. ;)

Oil and gas hold water in solution. But, that will not win you a bet in a bar. :no: The fact a gallon of gas produces 1.2 gallons of water will.
 
Does every one realize that the Lycoming oil sump bottom is a big flat cooling surface. that cooling surface will not get agitated enough to stir the water that is settled out to cause the water to circulate thru the system. (oil flow in that area simply enough to make it rise off the bottom)
and the cooling effect of the sump floor prevents the water from evaporating thru the oil above it. It will simply set there unless drained.

So you might as well leave it alone, use a good oil like Exion Elete with a good corrosion preventive in it and not worry about how often you should fly.

You might worry more about your own proficiency than corrosion.
 
Geico266 said:
Then you are a grease monkey. ;)

Oil and gas hold water in solution. But, that will not win you a bet in a bar. :no: The fact a gallon of gas produces 1.2 gallons of water will.
Click to expand...

I've never met a guy in a bar that was worried about my engine health. let alone one that would make this bet.
 
Tom, the water doesn't lay at the bottom of the sump. It gets churned around and mixes with the oil to form an emulsion. Anyone who flies in this colder climate has seen that chocolate-foamy gunk on a dipstick, and I have drained oil from airplanes that looked more like latte than oil. That's the oil/water emulsion.

That water needs heating to raise its vapor pressure and get it vaporizing. Water vapor occupies several hundred times the volume of liquid water, so it runs out of room in the crankcase and goes out the breather. Water will evaporate at room temperature, of course, but it evaporates much faster as its temperature rises. It doesn't need to reach a boil, just needs to get hot. And water in emulsion will evaporate slowly at ambient temperatures too, so it needs agitating as well as heating. That engine needs to run for a while. An engine that has run for a long flight and been shut down while still hot will have almost no water in that crankcase.


Vapor pressure: http://en.wikipedia.org/wiki/Vapor_pressure

Emulsion: http://en.wikipedia.org/wiki/Emulsion

Crankcase ventilation to control emulsions: http://books.google.ca/books?id=DoY...#v=onepage&q=crankcase water emulsion&f=false

Dan
 
Dan Thomas said:
Tom, the water doesn't lay at the bottom of the sump. It gets churned around and mixes with the oil to form an emulsion. Anyone who flies in this colder climate has seen that chocolate-foamy gunk on a dipstick, and I have drained oil from airplanes that looked more like latte than oil. That's the oil/water emulsion.

That water needs heating to raise its vapor pressure and get it vaporizing. Water vapor occupies several hundred times the volume of liquid water, so it runs out of room in the crankcase and goes out the breather. Water will evaporate at room temperature, of course, but it evaporates much faster as its temperature rises. It doesn't need to reach a boil, just needs to get hot. And water in emulsion will evaporate slowly at ambient temperatures too, so it needs agitating as well as heating. That engine needs to run for a while. An engine that has run for a long flight and been shut down while still hot will have almost no water in that crankcase.
Dan
Click to expand...

What will churn the oil in a 0-200 with a kidney sump. or in any Lycoming when the crank is in a different compartment?

If what you say is true, why does the 0-300 have corroded sumps. It is the only engine that has the crank in the same compartment as the oil.
 
Last edited:
Pictures of a Lycoming sump, it is not the crankcase compartment.
 

Attachments

  • Engines 001.jpg
    Engines 001.jpg
    179.4 KB · Views: 39
  • Engines 011.jpg
    Engines 011.jpg
    178.4 KB · Views: 39
  • Engines 023.jpg
    Engines 023.jpg
    17.9 KB · Views: 40
  • 0-235 sump.jpg
    0-235 sump.jpg
    1.6 KB · Views: 168
The pickup will get that oil and it will mix in the galleries if nothing else. But much of it happens as the vapor comes past the rings and is condensed and mixed in midair as the oil is being flung around.

I have taken the rocker covers off an engine after a short run in cool weather and found droplets of water in them, along with lots of rust. There's no shortage of water in the crankcase in some environments.

Dan
 
Look at the inside of the filler neck of a TCM IO-360, they rust in no time.

Most of that water goes right out the tail pipe but unless the ring seal is perfect it goes into the case as well. What ever is left at the end of the flight will condense out. If you don't cook it off in the next run it will build up in there
 
Dan Thomas said:
snip... An engine that has run for a long flight and been shut down while still hot will have almost no water in that crankcase.
Click to expand...

Could you expand on that? How does one, after a long flight, shut down with a not hot engine?
 
I think Lycoming recommends operating at least 1 hour each month, and Continental recommends operating at least 1/2 or 1 hour (not sure which) each week. So, I try to operate my Lycoming at least an hour every two weeks to a month. Sometimes it goes longer. But, besides engine issues with long spans between operations is that the batteries gradually deplete if otherwise not kept charged. An hour in one month is not enough time to keep them charged, especially in cold weather.
 
Dan's and duncan's statements are proof that the water stays in the engine, why?
 
Tom-D said:
Dan's and duncan's statements are proof that the water stays in the engine, why?
Click to expand...

There's always water, but keeping it to a minimum and running frequently to keep everything covered with oil will go a long way towards corrosion prevention.
 
skidoo said:
I think Lycoming recommends operating at least 1 hour each month, and Continental recommends operating at least 1/2 or 1 hour (not sure which) each week. So, I try to operate my Lycoming at least an hour every two weeks to a month. Sometimes it goes longer. But, besides engine issues with long spans between operations is that the batteries gradually deplete if otherwise not kept charged. An hour in one month is not enough time to keep them charged, especially in cold weather.
Click to expand...

Why not place a battery minder on it and leave it set?
 
Skylane81E said:
There's always water, but keeping it to a minimum and running frequently to keep everything covered with oil will go a long way towards corrosion prevention.
Click to expand...

That's exactly right….
You are never going to get it all out, Maybe just maybe you will if you fly it long enough to get the water back into solution before you pull the plug and drain it out.

The reason you will never get it all out is simple, it doesn't mix with a non detergent oil. and will condense out on parts high in the engine, and stay there. The only way you would get it all out would be to add a detergent to the oil prior to oil changes. I really do not recommend that.

As I've said before, for less than frequent flyers, use a oil that has a corrosion preventive as a portion of the additive package Exion elite is the best one in my humble opinion.
 
skidoo said:
Could you expand on that? How does one, after a long flight, shut down with a not hot engine?
Click to expand...

A long taxi in cold weather could do it, especially if there was a long, low-power glide right before landing.

Dan
 
You must log in or register to reply here.
Back
Top