HI have an old topflite kit P47 that I am completing and I notice the wing has a build in twist at the wing tip. What is the purpose of this on this wing. At the root rib on the trailing edge you use an alignment stick sarts at 5/8 and tapers to 1/4 at the tip...

Would this be considered washin since the tip of the wing trailing edge is twisted down instead of in an upward positon.

Thanks for responding

WASHIN is when the trailing edge of the wingtip twists downward , and is useful for rekitting your plane by causing it to snap at low airspeeds, such as on approach, by allowing the tips to stall before the root...WASHOUT is when the tip twists up, which causes the tip to stall later than the root, hopefully causing a gentler, straight-ahead (and hopefully recoverable) stall.

I guess the only thing I can think of washin would be used for, is if you like flying inverted ALOT! [8D]

I think we talked about this in that other thread. The actual dimensions of the stick don't mean nuthin' by itself....

The trailing edge jigging stick can't be used to determine if the wing is being built with washout or washin. You need to understand that the depth of the airfoil underside is changing as the wing tapers towards the tips. Because of this that 5/8 to 1/4 stick may be the right dimensions to actually build the wing dead flat or even with washOUT. To tell the real story you need to do a drawing with the root and tip ribs overlayed and with the deepest part of the rib sitting on a common "table" line and then show the trailing edge shimmed up by the amount of the strip you're talking about. THEN you use a protractor to measure the chord lines. The angle of the chord lines will tell you if you have a flat wing or what the washout angle actually is. Photocopy the root and tip ribs and do a layout up against a pencil line on a sheet of paper using a drawn on "stick" shim to present the ribs up against.

Washin is an increase in incidence. Washout is a decrease, you had it backwards. But like the other guy said, the tips have a lesser AOA than the wing root so as to prevent tip stall. In a high angle of attack situation, the root will stall first, causing the nose to drop and not the tip. Also you will still have airflow over the aileron so you still have control about your longitudnal axis.
Sean