The McDonnell XF-85 Goblin was a fighter aircraft conceived during World War II and intended to be carried in the bomb bay of the giant Convair B-36 bomber as a defensive "parasite fighter." Because of its small and rotund appearance, it was nicknamed "The Flying Egg."
McDonnell built two Goblin prototypes (USAF Serial no. #46-523 and #46-524). During wind tunnel testing at Moffett Field, California, the first prototype XF-85 was damaged. Consequently, it was the second aircraft that was used for the initial flight trials. As a prototype B-36 was unavailable, all XF-85 flight tests were carried out using a converted Boeing EB-29 Superfortress parent ship. McDonnell test pilot Edwin Schoch was assigned to the project, riding in the XF-85 while it was stowed aboard the EB-29B, before attempting a "free" flight on 23 August 1948. After Schoch was released from the bomber at a height of 20,000 ft (6,000 m), he completed a 10-minute proving flight at speeds between 180 and 250 mph, testing controls and maneuverability.
When he attempted a hook-up, it became obvious the Goblin was extremely sensitive to the bomber's turbulence, as well as being affected by the air cushion created by the two aircraft operating in close proximity. Constant but gentle adjustments of throttle and trim were necessary to overcome the cushioning effect. After three attempts to hook onto the trapeze, Schoch miscalculated his approach and struck the trapeze so violently that the canopy was smashed and ripped free and his helmet and mask were torn off. He saved the prototype by making a belly landing on the reinforced skid at the dry lake bed at Muroc.
With the first prototype's repairs completed, it also joined the flight test program, completing captive flights. While in flight, the Goblin was stable, easy to fly, and recoverable from spins, although initial estimates of a 648 mph (1,043 km/h) top speed proved optimistic. The first test flights revealed that turbulence during approach to the B-29 was significant, leading to the addition of upper and lower fins at the extreme rear fuselage, as well as two wingtip fins to compensate for the increased directional instability in docking.
Two main reasons contributed to the cancellation. The XF-85's deficiencies revealed in flight testing included a lackluster performance in relation to contemporary jet fighters, and the high demands on pilot skill experienced during docking revealed a critical shortcoming that was never fully corrected. The development of practical aerial refueling for conventional fighters used as bomber escort was also a factor in the cancellation. The two Goblins flew seven times, with a total flight time of 2 hours and 19 minutes with only three of the free flights ending in a successful hookup. Schoch was the only pilot who ever flew the aircraft.