airship
The first effort at building an airship involved stretching the round balloon into an egg shape that was kept inflated by internal air pressure. These non-rigid airships, commonly called blimps, used ballonets, air bags located inside the outer envelope that expanded or contracted to compensate for changes in the gas. Because these blimps often collapsed under stress, designers added a fixed keel under the envelope to give it strength or enclosed the gas bag inside a frame. These semi-rigid airships were often used for reconnaissance flights. The rigid airship was the most useful type of airship. A rigid airship has an internal framework of steel or aluminum girders that supports the outside material and gives it shape. Only this type of airship could reach sizes that made it useful for carrying passengers and cargo. Related category AERODYNAMICS AND AERONAUTICS U.S. Centennial of Flight Commission Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |