Derivative aircraft and methods for their manufacture. In one embodiment, a derivative aircraft having a derivative wing is derived from a baseline aircraft having a baseline wing. In one aspect of this embodiment, the baseline wing can include an outboard wing portion and an inboard wing portion, the inboard wing portion having a forward inboard wing portion and an aft inboard wing portion. In a further aspect of this embodiment, the derivative wing can include a wing insert having a spanwise wing insert portion and a chordwise wing insert portion, the chordwise wing insert portion of the wing insert being interposed between the forward inboard wing portion and the aft inboard wing portion of the baseline wing, and the spanwise wing insert portion being interposed between the outboard wing portion and the forward and aft inboard wing portions of the baseline wing.