Hey. I was going through some Kit Building threads, and came across one where a member ( twostroke) is building a Great Planes PT-20. He had a question about the washout on his wing. I thought about asking this question in that thread, but figured more of us beginners may see the answer here. My question is, what is washout?

Washout is a twist in the wing where the angle of attack at the wing tip is lower than the angle of attack at the root of the wing. This causes the root portion of the wing to stall before the tip usually resulting in a controlled stall (ie: straight ahead)

If the tip stalls first it usually results in a wing dropping with a resultant spin or snap roll.

That's the easy definition, I'm sure somebody will come along and give you the aerodynamics later...but it's too late for me. ;-)

Don

Well, washout is what NJ is going to get plenty of today and tomorrow.. 3 - 5 inches of rain with wind. Yuk.

I had a trainer a while back that had a twisted wing.. it was obvious even to the most casual of observers. The plane flew ok, but it did some strange things when on approach. I eventually put it up and build a different one. The instructor was pretty impressed with the way it flew on approach.. thought it was the strangest thing he ever flew. The twist was because of the way I built it. That was back in 1977 when I first got interested in the hobby.

CGr.

Good answers, but to elaborate a little...

Picture standing along side your plane, grabbing the wing tip and twisting it so the LE is down and the TE is up. Do that to both wings and that is what washout is - of course, the amout of twist is very slight - like maybe 1/4"

Thanks Guys.

We here in Manitoba, will receive our own version of washout in a couple of weeks. This white stuff is melting, and it will all become liquid in time. Alot of the liquid version comes from the south, but one thing I know for sure, is that all of us in the Central North, both U.S. and Canada, always know what to expect in the spring. After the Washout, it's Flying Time!!!