US Patent 10266252 Wing extension winglets for tiltrotor aircraft

A pylon assembly for a tiltrotor aircraft includes a rotor assembly operable to rotate between a generally vertical orientation, in a VTOL flight mode, and a generally horizontal orientation, in a forward flight mode, and having an intermediate orientation therebetween, in a conversion flight mode. The rotor assembly includes a proprotor operable to produce a slipstream. A wing extension, positioned outboard of the rotor assembly, has a minimal dimension and an outboard end. A winglet is coupled to the outboard end of the wing extension and has a minimal dimension. The wing extension and the winglet are operable to rotate generally with the rotor assembly such that the minimal dimensions of the wing extension and the winglet remain in the slipstream of the proprotor.