The C 7 passing over the White House this morning on her trip from Hampton Roads to Bolling Field

The main types of airship are non-rigid, semi-rigid, and rigid. Non-rigid airships, often called "blimps", rely on internal pressure to maintain the shape of the airship. Semi-rigid airships maintain the envelope shape by internal pressure but have a supporting structure. Rigid airships have an outer structural framework which maintains the shape and carries all structural loads, while the lifting gas is contained in internal gas bags or cells. Rigid airships were first flown by Count Zeppelin and the vast majority of rigid airships built were manufactured by the firm he founded. As a result, all rigid airships are sometimes called zeppelins. In early dirigibles, the lifting gas used was hydrogen, due to its high lifting capacity and ready availability. Helium gas has almost the same lifting capacity and is not flammable, unlike hydrogen, but is rare and relatively expensive. Airships were most commonly used before the 1940s, but their use decreased over time as their capabilities were surpassed by those of aeroplanes.

Airplanes and blimps above National Mall, Washington Monument, Potomac river and around.

Founded in 1917 as The Flying Field at Anacostia, the Bolling Field was the first military airfield near the United States Capitol. It was renamed Anacostia Experimental Flying Field in June 1918. Throughout the Second World War, Bolling Field served as the aerial gateway to the US capital Washington D.C. After WWII, Bolling Field's property became Naval Air Station Anacostia and a new Air Force base, named Bolling Air Force Base, was constructed just to the south of the field in 1948.