View Full Version : wing wash on a J3

05-28-2009, 01:51 PM
If the wing wash was 1 3/4" instead of 3/8', how would the piper cub perform?

05-28-2009, 05:42 PM
Mon bon Leo

I think it will be a loosy performer but the stall will be smooth.


11-20-2009, 10:36 PM
Where can I get spec. on J3 wing wash and dihedral. Thanks

11-21-2009, 07:38 AM
If this link works it should help you.

bob turner
11-21-2009, 02:34 PM
The twist from butt rib to the measuring rib is supposed to be around 2 1/2 degrees, and can be measured with a Smart Level. I had computed 2.6 degrees using the angle of incidence + that 3/8" block.

When the wing is on saw horses, you need a 1.4" block, for the stock setting.

Most Cubs I have measured have more like 1 to 1 1/2 degrees of twist. They fly just fine, and the stall seems docile without any dropping wings. I can detect no increase in cruise speed, although there must be some slight improvement. My Decathlon has zero wash, and stalls just fine.

I get into serious trouble when I use the terms "wash in" and "wash-out". I don't even care . . .

11-21-2009, 04:43 PM
Thanks you very much for the info. You guys have been a great help.