Abstract: A propulsion system for a non-rigid and at least semi-buoyant vehicle, the vehicle including a pressure stabilized gasbag having a gondola mounted on the bottom thereof. The gasbag further includes catenary curtains extending from the top of gasbag to the bottom of the gasbag and attached thereto. In detail, the propulsion system includes a first pair of tubular members attached, preferably pivotally attached, by one of their ends to the gondola and which extend through the air bag and exit out the top thereof and having propulsion units, preferably turbo-prop engines, attached to their opposite ends. A second pair of tubular members is attached by one of their ends to the gondola, preferably pivotally attached, and extends into the gasbag and having their opposite ends terminating therewithin. A horizontal tubular member extends through the gasbag and has its ends extending out of the sides thereof and is attached to the opposite ends of the second pair of tubular members in the middle thereof.

Abstract: A non-ridged semi-buoyant vehicle includes a pressure stabilized gasbag having a longitudinal, vertical and horizontal axis, top, bottom and side surfaces and front and rear ends and an aerodynamic shape capable of producing lift. Within the gasbag are first and second vertical catenary curtains attached to the top and bottom surfaces between the sides of the gasbag. These first and second catenary curtains are positioned on either side of the longitudinal axis extending from the front end along a first portion of the gasbag. A pair of first and second Y shaped catenary curtains are coupled to the first and second vertical catenary curtains and extend along a second portion of the gasbag. The arms of each of the Y shaped curtains are attached to the top surface and the legs are attached to the bottom surface of the gasbag. First and second pairs of vertical catenary curtains are coupled to the first and second pairs of Y shaped catenary curtains, respectively, and extend to the rear end of said gasbag.

Abstract: The invention is a non-ridged, semi-buoyant vehicle. In detail, the invention includes a pressure stabilized gasbag having front and rear ends and an aerodynamic shape capable of producing lift, and longitudinal, vertical and horizontal axis, the tail end of the gasbag extending outward along the horizontal axis from each side of the longitudinal axis toward said front end at an acute angle to the horizontal axis. A horizontal tail surface is mounted outboard of the rear end of the gasbag, having a trailing edge extending outward along the horizontal axis from each side of the longitudinal axis toward the front end at the acute angle to the horizontal axis. A horizontal ridged beam is mounted outboard of the rear end of the gasbag that extends outward along the horizontal axis from each side of the longitudinal axis toward the front end at the acute angle to the horizontal axis with the horizontal tail surface mounted to the beam. The preferred acute angle is approximately 20 degrees.