Do any aircraft possess washed-in wing characteristics? I have been teaching ground school at my local Canadian Air Cadets. When I was teaching about the wing twist of an aircraft, I was asked if any aircraft possess washin characteristics (vs washout). The book teaches that wing twist is either washin or washout. Washout is supposed to decrease the wingtip's angle of attack in order to promote better stall characteristics, while washin does the opposite (worse stall characteristics). Not sure why one would want washed-in wingtips, but was wondering if anyone knew of such aircraft.
According to Wikipedia, the Grumman X-29 had washed-in wings, as its considerable forward wing sweep gave it a strong tendency to stall at the roots.  As the wing roots on a forward-swept-winged aircraft are located aft of the wingtips, a root stall on such an aircraft would cause a strong pitch-up tendency, so the X-29's wings were washed in to mitigate the root-stall tendency.