No, that is not what "wash out" means!  Wash-out means that the wings are twisted so that the tips are pointed slightly downward compared to the roots.  It's done one aircraft that need to perform much better flying upright than upside down, and it is either done to avoid tip stalls, or to make a "hershey bar" wing oh so slightly more efficient.

Wash-out is undesirable on a stunt plane.

Tip shape doesn't have a huge impact on flight performance.  There's some subtleties with how tip shape makes the plane handle in the wind which, frankly, I can't keep track of.  Look at the shapes of tips on airplanes flown in the top 20 at the Nats, pick one you like, and run with it.

No, that is not what "wash out" means!  Wash-out means that the wings are twisted so that the tips are pointed slightly downward compared to the roots. 

Wash-out is undesirable on a stunt plane.

Actually, "wash out" is when the trailing edge of the wing is twisted upward at the tip.  Often employed on free flight models to delay tip stall.  "Wash in" is when the trailing edge at the wing tip is twisted to a higher angle of incidence, promotes tip stalling and generally should be avoided with any kind of airplane, model or full size though wash in might be employed on a free flight model for certain issues with flight trim.

An interesting example of "wash out" is to examine the wing tip of the F-15.  The wing tip airfoil is highly undercambered and normally is operating at a noticeable negative angle of attack (wash out).  That wing tip does not start lifting until the aircraft is pulling several positive G's, as in a hard turn.  It will not help much when pulling any negative G's, which most fighter planes do not try to do.

Like Tim suggested,  CL stunt planes should avoid any kind of twist - period.

Keith

Actually, "wash out" is when the wing is twisted upward at the tip.

Oh dangit, it's that free flighter vs. the rest of the world terminology difference.  When you're building a free-flight wing you shim the trailing edge up to get wash-out.  But that means that the angle of attack of the tip is down (which is what you find in the full-scale aeronautical texts).

I'm not going to say I'm backwards, here, but if open my mouth at a free-flight field I'll try to get it right...

Oh dangit, it's that free flighter vs. the rest of the world terminology difference.  When you're building a free-flight wing you shim the trailing edge up to get wash-out.  But that means that the angle of attack of the tip is down (which is what you find in the full-scale aeronautical texts).

I'm not going to say I'm backwards, here, but if open my mouth at a free-flight field I'll try to get it right...

The terms "wash out" and "wash in" apply the same in full size aviation as well as model airplanes, including free flight model airplanes.

Keith

For a while, there was a certain segment of the stunt "guru club" advocating tips which had taper, front to rear, similar to the Flite Streak.  No good scientific explanation was given, except that it was "better".

I design wingtips to complement the overall design lines.  Some round.  Some elliptical, some just squared.

"Actually, "wash out" is when the wing is twisted upward at the tip."

To make this as easy as possible to understand,

Washout:

The root airfoil is at a greater angle of attack than the tip airfoil.

So, the root could be designed to be at a positive "2" degrees and the tip could have a positive "1" degree or "0".

Best explanation I can do as a washed up former commercial pilot. 

Make your wing tips like the SV 11 or Pathfinder. Randy Smith says it's better.

Everything I have designed since 1965 has had swept tips.  I have no idea if they are actually better, I just think they are and they look cool.

Ken

For a while, there was a certain segment of the stunt "guru club" advocating tips which had taper, front to rear, similar to the Flite Streak.  No good scientific explanation was given, except that it was "better".

I design wingtips to complement the overall design lines.  Some round.  Some elliptical, some just squared.

I'm with you Floyd. At our Renolds numbers it doesn't matter...... We need the DRAG in the vertlcal portion of out maneuvers anyway.

Jerry