Abstract: A lighter-than-air aircraft (1) having a gas-filled hull (2) and a pair of spaced apart landing gear units (11, 12) on the underside of the hull arranged on opposite sides of a longitudinally extending central vertical plane of the hull. Each landing gear unit (11, 12) comprises bag skirt means (5–7, 5?–7?), means for supplying air to and removing air from the bag skirt means and actuating means operable to move the bag skirt means between an operative configuration for containing one or more air cushions and an inoperative configuration.

Abstract: A method of launching inflatable airship apparatus (3) for subsequent ascent to high altitude for operation as an airship having a hull (4) formed from an inflated flexible gas containment envelope (5), payload (15), drive motor (6) mounted at the stern of the hull and cables (26,27), for supporting the payload (15) within the hull (4), connected to the drive motor (6) and to the hull at, or adjacent to, a nose portion of the hull. The method comprises partially inflating the gas containment envelope (5) with a lighter than air gaseous medium to cause the nose portion to rise within a vertical launch enclosure (10) to position the partially inflated gas containment envelope (5) in a launch position, and subsequently releasing the partially inflated gas containment envelope (5) from its launch position through an open top of the vertical enclosure so that the envelope ascends clear of the vertical enclosure (10) and lifts the payload means (15) and drive motor (6) by means of the cables.

Abstract: An airship (1) comprising gas envelope means for providing in use a hull (2) with a generally longitudinally extending longitudinal axis (20) and solar cell array means (3) arranged in use to be mounted on the outside of the hull (2). The solar array means (3) are arranged in use to extend around only a part of the circumference of the hull (2) and are turned about the longitudinal hull axis (20) to control the amount of incident solar radiation collected by the solar cell array means (3).