Flying with frost on the plane

cowman said:
The one or two times this has come up for me I just grabbed a towel/t-shirt/whatever I had and rubbed as much of it off as I could.
Click to expand...

I used the canopy cover of my rental plane. Yes, we can actually get frost from time to time in SoCal!
 
noahfong said:
Here's what AC 120-58 has to say about frost on the wings:

"Test data indicate that ice, snow, or frost formations having a thickness and surface roughness similar to medium or coarse sandpaper on the leading edge and upper surface of a wing can reduce wing lift by as much as 30 percent and increase drag by 40 percent."
Click to expand...

"as much as"

But I would never ever encourage anyone to fly with any frost.
 
https://www.aopa.org/-/media/Files/AOPA/Home/Pilot-Resources/ASI/Safety-Advisors/sa11.pdf "Wind tunnel and flight tests have shown that frost, snow, and ice accumulations (on the leading edge or upper surface of the wing) no thicker or rougher than a piece of coarse sandpaper can reduce lift by 30 percent and increase drag up to 40 percent. Larger accretions can reduce lift even more and can increase drag by 80 percent or more."
:eek::eek:

I find this hard to believe since have seen leading edges with peeling paint that are pretty rough but fly normally. I would like to see the raw data. Maybe it is airfoil dependent. A 30% decrease lift would require a 14% increase in AS to compensate or from 50 to 57 knots. And coarse sandpaper is pretty vague. What grit? I am not reckless but I want honest data not a scare story.
 
Snowmass said:
https://www.aopa.org/-/media/Files/AOPA/Home/Pilot-Resources/ASI/Safety-Advisors/sa11.pdf "Wind tunnel and flight tests have shown that frost, snow, and ice accumulations (on the leading edge or upper surface of the wing) no thicker or rougher than a piece of coarse sandpaper can reduce lift by 30 percent and increase drag up to 40 percent. Larger accretions can reduce lift even more and can increase drag by 80 percent or more."
:eek::eek:

I find this hard to believe since have seen leading edges with peeling paint that are pretty rough but fly normally. I would like to see the raw data. Maybe it is airfoil dependent. A 30% decrease lift would require a 14% increase in AS to compensate or from 50 to 57 knots. And coarse sandpaper is pretty vague. What grit? I am not reckless but I want honest data not a scare story.
Click to expand...
Probably a Challenger airfoil.
 
Snowmass said:
https://www.aopa.org/-/media/Files/AOPA/Home/Pilot-Resources/ASI/Safety-Advisors/sa11.pdf "Wind tunnel and flight tests have shown that frost, snow, and ice accumulations (on the leading edge or upper surface of the wing) no thicker or rougher than a piece of coarse sandpaper can reduce lift by 30 percent and increase drag up to 40 percent. Larger accretions can reduce lift even more and can increase drag by 80 percent or more."
:eek::eek:

I find this hard to believe since have seen leading edges with peeling paint that are pretty rough but fly normally. I would like to see the raw data. Maybe it is airfoil dependent. A 30% decrease lift would require a 14% increase in AS to compensate or from 50 to 57 knots. And coarse sandpaper is pretty vague. What grit? I am not reckless but I want honest data not a scare story.
Click to expand...

100%. Just like the '178 seconds to live' nonsense. Using fear tactics instead of actually explaining the risk & how to mitigate it.
 
Though I don’t live where we get much frost, I remember ferrying an airplane up north and woke up one morning to find my airplane covered with a foot of snow. Took more than an hour with a borrowed ladder, push broom and a rope to deice the airplane. If the frost is thin, you can “polish” it by tossing a rope over the wing and gently see-saw back and forth until either the frost is removed or “polished smooth.” A small airlplane like a Luscombe is easy to defrost; the Beaver I was flying at the time, not so much.
 
Zeldman said:
When I first started flying in Alaska, the accepted frost procedure was to polish the frost on the wings with a glove covered hand. Only the frost on top of the wing. It was perfectly acceptable to have frost on the bottom of the wing. Then load up and go.

Now the required procedure is to remove all frost before flight.
Click to expand...

Oh the good ole days. We also used to fly with sheets of plywood and canoes tied to the struts.
 
SToL said:
Oh the good ole days. We also used to fly with sheets of plywood and canoes tied to the struts.
Click to expand...

There is a de Havilland joke in there somewhere.... :D

Something along the lines of: Isn't that how the Beaver was created?
 
SToL said:
Oh the good ole days. We also used to fly with sheets of plywood and canoes tied to the struts.
Click to expand...

I never did plywood or canoes, but I did carry a complete dead moose once... and it was sent from one village to another via US Mail.

I guess postage was cheaper than cargo.
 
External loads are common. The only difference between now and 20 years ago is the permit process. But that only applies to certificated aircraft. EXPs don't need a permit.
 
birdus said:
Does anyone here have any friends who have flown with frost on the plane? I'm just wondering how significant an effect it actually has on how the plane flies. For example, if a Luscombe owner (other than me) were to fly with frost on the plane, would it stall at, say, 55 instead of 48? Would the aforementioned Luscombe owner (not me) even notice a difference?
Click to expand...

If you want to fly your airplane with frost on it, have at it.
 
In Far West Alaska, we put covers on the wings and had electric heaters blowing air into the wings through the air vent holes. Getting them off was sometimes no fun if they were stuck on. The rest of the plane was just brushed off and a rope drawn over the surfaces...

We also kept the engine oil on a Coleman stove in a pot inside the hangar. Poured it in and cranked her up!
 
You must log in or register to reply here.
Back
Top