The Lockheed Martin P-791 is an experimental aerostatic/aerodynamic hybrid airship developed by Lockheed Martin corporation. The first flight of the P-791 was on 31 January 2006 at the company’s flight test facility on the Palmdale Air Force Plant 42. It has a unique tri-hull shape, with disk-shaped cushions on the bottom for landing. As a hybrid airship, part of the weight of the craft and its payload are supported by aerostatic (buoyant) lift and the remainder is supported by aerodynamic lift. The combination of aerodynamic and aerostatic lift is an attempt to benefit from both the high speed of aerodynamic craft and the lifting capacity of aerostatic craft.
The P-791 Hybrid Air Vehicle can be designed as an unmanned or manned intelligence gatherer or transport vehicle. As an eye in the sky, this remarkable airship can stay aloft for up to three weeks at an altitude of 20,000 feet. Loaded with cameras, infrared sensors, communications relays, and other payloads, the Hybrid Air Vehicle can provide American and allied forces a clear picture of the battlefield. As a transport vehicle, the Hybrid Air Vehicle can be sized to move equipment and troops cost effectively to unimproved forward areas.