What am I seeing on the leading edge?

[snopercod]

Originally Posted by Vlad

Likely a very thin layer of ice is my guess.

That's what I was concerned about. I've never flown in icing conditions and don't know what it looks like (other than photos). Neither did I know that one could experience icing in clear weather. My laminar flow airfoil doesn't tolerate icing well so I was real concerned. I didn't notice any degradation in my 165 Kt TAS at the time so I just shrugged and pressed on. I reviewed the ATC audio from my Garmin Virb and they were reporting a -1 deg C dewpoint on the ground. Thanks for your opinion.

[BobTurner]

If your OAT is accurate, it is very unlikely you had icing at +5 C.

[snopercod]

Originally Posted by BobTurner

If your OAT is accurate...

I guess I need to do a single-point calibration check on my Davtron 5-in-1 to find out. Dipping the probe in some ice/water mix shouldn't be too difficult. That will give me something to do while I'm suffering through all this non-flying weather. Thanks for the idea.

[sblack]

Originally Posted by BobTurner

If your OAT is accurate, it is very unlikely you had icing at +5 C.

The temp on the LE will be considerably lower due to the low static pressure at that location.

[runt]

I assume we are talking about the white area on the leading edge.

I have seen plenty of icing and that doesn't really look like icing. Notice how it doesn't come all the way to the root for one thing. It looks to stop about half way. Ice would be on all of the leading edge. The air in Colorado is pretty dry. Doubtful you would collect ice in that flight condition from what I'm seeing in the photo.

Again, if we are talking about the white area I would guess it's a reflection of the clouds in the distance. Light does funny things.

The plane I normally fly has heated (shiny) leading edges. When we go through clouds and the light is right you would swear there is a layer of ice when in reality it is simply a reflection.

Hard to say based on that picture.

Did it disappear all at once? Ice would break off in sections.

[scrollF4]

Originally Posted by runt

Did it disappear all at once? Ice would break off in sections.

Just as a point of fact: aircraft icing will indeed break off in sections particularly as it starts to melt. However, if it remains frozen while flown through clear dry air, it will tend to sublimate. Clear air sublimation is the conversion of matter from a solid (ice) directly to a gas (water vapor). Happens faster in jets, but more slowly in slower aircraft because slower speeds lesson the wind/ice friction.

I now return you to your originally scheduled topic. I can't tell what your photo is showing, sorry.

[BobTurner]

Originally Posted by sblack

The temp on the LE will be considerably lower due to the low static pressure at that location.

Lower, yes. 5 C (9 F) lower? Unlikely.

[brad walton]

I've always thought of a change of state from solid to vapor as being sublimation

[scrollF4]

Originally Posted by brad walton

I've always thought of a change of state from solid to vapor as being sublimation

Yep, you're right. Corrected.

[snopercod]

This morning I did a single point calibration of my OAT sensor/display. I dipped the probe in a bath of crushed ice and water, and the Davtron indicated 32F/0C. My Fluke read 32.1F. At ambient the Davtron read 43F and the Fluke read 43.1F. So the 5C reading was probably accurate. BTW, my OAT probe is located under the wing, well away from the cowling exit air. I wish I had known about Skew-T charts last year