Skyhookers: An Illustrated History of Hook-On Aircraft and Their Dirigible Motherships

"... Sky Hookers will provide a wealth of obscure and largely unknown detail concerning these hybrid machines and their niche in aviation history." - Flightline: Newsletter of the American Aviation Historical Society

From the First World War's Zeppelins to the Second World War's large bombers, military aircraft were vulnerable to fast, manoeuvrable interceptors. To address this, fighter escorts were used, but their limited range often left bombers exposed. A solution was the use of Composite aircraft, where larger bombers carried smaller, short-range fighters, which could be launched and retrieved as needed.

Zeppelins, particularly vulnerable to interceptors, were ideal for this concept. During the First World War, Germany briefly experimented with carrying parasite aircraft, while the British conducted post-war trials using airships like His Majesty's Airship R-23 and R-33, carrying fighters such as the Sopwith Camel and de Havilland DH.53 Humming Bird. However, successful hook-on/retrievals were only achieved with the Humming Bird.

The US Navy and Army further developed this concept. In 1918, the Navy launched a Curtiss JN 'Jenny' from a C-1 Blimp, and in 1924, the Army successfully flew a Sperry Messenger from a TC-Class airship. The US perfected the carry/launch/retrieval method for airship defence and scouting, notably with the USS Los Angeles, which carried aircraft on a 'trapeze' device. The Akron and Macon airships, with internal storage for aircraft, further advanced this technique, making them some of the most remarkable aircraft of their time.