Lockheed F-117A Stealth Fighter
The F-117A was designed to resolve two conflicting requirements - stealth and the ability to fly - but does so very well. Inevitably unstable in all three axes, it is made 'flyable' by a GEC Astronics flight control system, as used by the F-16.
The faceted shape is not ideal for smooth airflow, but there are advantages. Use is made of 'vortex lift', whereby low pressure vortices are formed over the wing and body at high angles of attack, augmenting lift. The high sweepback is necessary, because due to aerodynamic and structural demands, the leading edges of the wings must have appreciable curvature. This means that they will reflect radar, but the sweepback ensures that they reflect a frontal radar signal sharply away from the source.
The sharply swept wing behaves in some ways like a delta, especially at low speeds, when, due to the low aspect ratio and lack of any high-lift devices, high angles of attack are necessary. This is one reason for the unusually high take-off and landing speeds. "
From the manual