Abstract: An aircraft having an upswept tail section fuselage includes a single pair of large vortex generators mounted in the vicinity of the break in the fuselage ahead of or at the beginning of the tail upsweep, each vortex generator being mounted on a side of and adjacent the bottom of the fuselage. The vortex generators, which may be plates or fins, develop strong transverse outflow from the vertical plane of symmetry that relieves or delays the tendency to flow separation by acting on the external flow field while at the same time energizing the boundary layer to increase its resistance to separation. The vortex generator may be thin or slightly thickened, flat or airfoil shaped, and may have triangular, straight, tapered, or reverse tapered planforms and may be rigid or flexible. Either one or both edges may be blunted, although sharp edges are preferred.