The McDonnell XF-85 Goblin

A member of the Check Your 6! Facebook group recently shared a post from a company called Geektown, a 3D print company. While Geektown offers merchandise that I am far from interested in, they do have a line called Hot Skies/Cold Seas that have a few oddball "could-have-been" aircraft that made it into the test phase but not into production. One of the offerings is a six pack of McDonnell XF-85 Goblins, a parasite fighter that was to be used to protect bombers during missions that would have been beyond the range of conventional fighters. The Goblin would be carried under the bomber, then launch when enemy aircraft were nearing the bomber formation. It would be retrieved by connecting to a trapeze via a retractable hook that extended in front of the canopy on the Goblin.

The use of parasite aircraft extended back to the Great War, with planes being considered for use under airships. The Unites States Navy did put the parasite idea into use during the 1930s on the airships Akron and Macon. During World War Two both the Soviets and the Germans toyed with parasite designs and testing, with the Soviets actually using parasites in 1941 to attack a bridge. The United States put out request for proposals in late 1942, but McDonnell that submitted a proposal concept.

The XF-85 was originally conceived as a piston engined fighter that would be carried partially exposed under a bomber, but the United States Army Air Force rejected this concept due to the increased drag caused by carrying the parasite. Future developments led to the Goblin being placed within the bomber's hold, and it was conceptualized that a B-36 could carry up to three Goblins, providing a sort of flying carrier to support the other bombers on any given mission.

However, the Goblin seemed destined for failure - the first prototype was accidently dropped from a height of forty feet during wind tunnel testing. Additional testing proved that the Goblin, while showing promise, would not be fast enough to deal with the generation of enemy jets it would face, and recovery of the parasite was problematic due to the buffeting of air around the bomber. Only a few successful hookups were completed during testing, and the program was canceled.

In Check Your 6! Jet Age terms I have cobbled together these stats:

There is an existing XF-85 at the National Museum of the United States Air Force in Dayton.