Chaps & chapesses... fun as this is, it's not what some of you may be thinking - it's simply a poncey term for being on the back of the drag curve, i.e. slower than best l/d. So around Vx is a decent approximation crossover as posted...
And yes, it will vary with weight.
Crossposted with the above, but just to add, it doesn't have to be flapped, there will be different speeds for different configs.
Last edited by Mark1234; 10th Feb 2009 at 00:48.