Key Points and Summary – The McDonnell XF-85 Goblin was a bizarre Cold War experiment: a tiny, egg-shaped “parasite fighter” designed to be carried inside the bomb bay of a massive B-36 bomber.
-The plan was to launch the Goblin mid-air to defend the bomber from interceptors and then retrieve it on a trapeze. The concept was a complete failure.
-The violent turbulence underneath the mothership made the trapeze hook-up nearly impossible and extremely dangerous for the pilot. After only seven terrifying test flights, half of which ended in emergency belly landings, the program was canceled.
-We Visited the XF-85: National Security Journal was able to visit and tour the exterior of a real-life XF-85 at the U.S. Air Force Museum in Dayton, Ohio. All photos and videos are from that visit and are original, taken by Editor-in-Chief Harry J. Kazianis.
Meet the XF-85 Goblin: A Failed Experiment
During the Second World War, the Americans learned a harrowing lesson: unsupported bombers are easy prey for enemy aircraft. The U.S. Air Force sought a way to provide an escort for its bombers that could respond to enemy fighters in any scenario. To remedy this problem, designers thought up the concept of a parasite fighter, a fighter that could dock onto bombers and respond instantly to enemy threats.
The result was the McDonnell XF-85 Goblin, the smallest manned jet aircraft ever created. Unfortunately, the project did not go very far and was canceled after two prototypes were built.
Development of the Goblin Parasite Fighter
The origins of the XF-85 Goblin can be traced to the strategic realities of the late 1940s. During World War II, the U.S. Army Air Forces had learned the hard way that unescorted bombers were highly vulnerable to enemy fighters.
XF-85 at USAF Museum July 2025. Image Taken by Harry J. Kazianis/National Security Journal.
The introduction of long-range escort fighters, such as the P-51 Mustang, helped turn the tide in the European air war; however, the problem of range persisted. As the Cold War dawned, the U.S. Air Force began developing the Convair B-36 Peacemaker, a massive intercontinental bomber capable of flying missions over 10,000 miles.
The B-36 was designed to deliver nuclear payloads deep into Soviet territory, but no existing fighter could escort it for the entire journey. The Air Force needed a new solution, one that didn’t depend on overseas bases or mid-air refueling, which was still experimental and unreliable.
Enter the concept of the parasite fighter. The idea was not entirely new; experiments with parasite aircraft had been conducted as early as the 1930s.
The basic concept was to carry a small fighter aircraft inside or attached to a larger “mother ship,” in this case, the B-36.
When enemy fighters approached, the parasite would be released to defend the bomber, then return and dock mid-air. This would allow the bomber to carry its escort, eliminating the need for external support.
Design and Specs
In 1945, the U.S. Army Air Forces contracted McDonnell Aircraft Corporation to develop a prototype parasite fighter specifically for the B-36. The result was the XF-85 Goblin, a tiny jet-powered aircraft designed to fit inside the B-36’s bomb bay.
XF-85 Goblin Up Close National Security Journal Photo.
The Goblin was an exemplar of compact engineering. It measured just under 15 feet in length and had a wingspan of about 21 feet. Its small size was dictated by the dimensions of the B-36’s bomb bay, which imposed strict limitations on the aircraft’s design.
The Goblin was powered by a single Westinghouse J34 turbojet engine and was armed with four .50 caliber machine guns. It had no landing gear, only a small retractable skid for emergency landings because it was never intended to land on a runway. Instead, it would be launched and recovered mid-air using a trapeze mechanism that extended from the bomber’s bomb bay.
B-36 Bomber Dayton, Ohio USAF Museum. Image Credit: National Security Journal.
The Goblin’s design was both innovative and unconventional. Its fuselage was egg-shaped, with a bubble canopy for the pilot and stubby wings that could be folded to fit inside the bomber. The aircraft was designed for short bursts of high-speed combat, not for long-range missions. Its top speed was around 650 miles per hour, and it had a range of about 445 miles, which was enough to engage enemy fighters and return to the mother ship.
The Goblin’s primary mission was to defend the B-36 from Soviet interceptors during the most dangerous part of its mission: the final approach to the target and the return flight through contested airspace.
The XF-85 Goblin Takes Flight
Flight testing of the XF-85 began in 1948, but not with the B-36, which was still in development. Instead, the Goblin was tested using a modified B-29 Superfortress as the mothership. The tests were conducted at Muroc Army Air Field (now Edwards Air Force Base) in California.
The first flight took place on August 23, 1948, with test pilot Edwin F. Schoch at the controls. The Goblin was released from the B-29 and flew successfully, but the attempt to re-dock with the trapeze mechanism failed. Turbulence from the bomber’s wake made the docking process extremely difficult, and the Goblin collided with the trapeze, damaging its canopy. Schoch was forced to make an emergency landing using the skid, which he did successfully.
XF-85 Goblin Wing Close Up. Image Credit: National Security Journal Taken on July 19, 2025.
Throughout the test program, the Goblin was flown seven times, but only three successful mid-air dockings were achieved. The primary problem was the difficulty of reattaching to the trapeze in turbulent air. The pilot had to maneuver the tiny fighter with extreme precision while flying in the disturbed airflow beneath the bomber.
Even with skilled pilots, the process was dangerous and unreliable. Additionally, the Goblin’s performance was inferior to that of contemporary jet fighters like the F-86 Sabre and the MiG-15, which were faster, more maneuverable, and better armed.
In 4 Words: Destined to Fail Badly
The problem of redocking ultimately led to the XF-85’s downfall. As a result of these challenges, the Air Force began to lose interest in the parasite fighter concept as a whole. At the same time, aerial refueling technology was rapidly improving.
The development of reliable in-flight refueling systems enabled long-range escort fighters to accompany bombers for the entire duration of their missions. This rendered the Goblin and parasite concept largely obsolete as a whole fighter.
XF-85 Sign at USAF Museum July 19 2025. Image Credit: National Security Journal Photo.
In 1949, the XF-85 program was officially canceled. Only two prototypes were built, and neither ever flew in combat. As strategic bombers evolved, the need for escorts gradually diminished. In cases where an escort was still required, aerial refueling enabled conventional fighters to keep pace with bombers.
Throughout modern history, designers have considered numerous ways to protect bombers from enemy fighters and air defense, with the parasite fighter concept being just one of many ideas. In the late 1950s and beyond, supersonic flight was seen as the solution to this problem. Still, as Soviet air defenses became more sophisticated, stealth became the primary means of protection and has remained so to this day.
About the Author:
Isaac Seitz, a Defense Columnist, graduated from Patrick Henry College’s Strategic Intelligence and National Security program. He has also studied Russian at Middlebury Language Schools and has worked as an intelligence Analyst in the private sector.
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