McDonnell XF-85 Goblin by MPM

1/72 scale
Kit No. 72042
Cost: $16.00 (aftermarket)
Decals: One version, U.S. Air Force
Comments: Delicate engraved panel lines; photo-etch parts for cockpit and wing fins

History

The McDonnell XF-85 Goblin was designed to be an internally carried fighter escort for the long-range Convair B-36 bomber, which flew beyond the range of conventional escort fighters of the time. The idea was that the B-36, which was expected to penetrate deep inside enemy territory, would carry its fighter escort with it, lowering the XF-85 on a trapeze arrangement and releasing it only once the bomber was under enemy attack. Once the enemy fighters were successfully driven away, the XF-85 would fly under the bomber, re-attach itself to the trapeze, fold its wings and be lifted back into the bomb bay of the B-36. Because of its small and rotund appearance, it was nicknamed “The Flying Egg”.

The Goblin’s decals are by PropagTeam. MPM’s kit includes photo-etch parts for the cockpit and wings and films for the instrument panel.

The B-36 and its little parasite fighter were initially ordered by the U.S. Army Air Force (USAAF) in December 1941, based on the possibility of Great Britain falling to Nazi Germany, and the resulting need for a long-range bomber that could attack Germany from bases in the United States. But as the war progressed it became clear that Germany, not Britain, would lose. In any event, the B-36 did not make its maiden flight until after the war, on August 8, 1946, nearly one year to the day after the first atomic bomb attack on Japan. By that time, the perceived enemy was not Germany but the Soviet Union, underscoring the need not merely for a long-range conventional bomber, but for a truly intercontinental bomber that was capable of delivering nuclear weapons.

The only company that expressed willingness to undertake such the design of such an unconventional fighter was McDonnell Aviation, which had experimented with cutting edge aircraft design during the war in the form of the XP-67 Moonbat. On October 9, 1945, McDonnell was tasked with designing a parasite fighter for the USAAF, which could be stored inside the bomber during flight until needed. A contract for two prototypes was signed in March 1947.

Herman D. Barkley designed an egg-shaped aircraft around the Westinghouse J34-WE-7 turbojet, which featured a pressurized cockpit and ejection seat. The low mid-wing had a 37-degree sweep, with leading edge slats and large ailerons on the trailing edge. The tail had three fins and dihedral horizontal tailplanes. The XF-85 Goblin had no landing gear but was fitted with a retractable hook to attach the fighter to a trapeze bar which was extended from the plane’s bomb bay during the landing and retrieval of the parasite aircraft. The air intake of the jet engine was located in the fighter’s nose, where there were plans to site four .50 caliber machine guns (similar to the layout of the six-gunned F-86 Sabre). The first flight of the XF-85 was made on July 22, 1948, while the tiny plane was attached to the trapeze below an E-29B mother ship, nicknamed Monstro.

McDonnell’s XF-85 Goblin resting on a dolly in preparation for loading into a B-29 bomber for a test flight.

After spending the entirety of four flights hooked underneath the B-29 bomber, the Goblin was first released in flight August 23, 1948 at an altitude of 20,000 feet with test pilot E.F. Schoch at the controls. On the first flight, after a little over two hours it became obvious that the turbulence around the bomber created difficult control problems for the XF-85. Schoch was unable to re-attach the Goblin to its trapeze and had to make a belly landing at Muroc Dry Lake (later Edwards Air Force base). Fins were subsequently installed on the wingtips to improve stability. In flight, the tiny fighter was amazingly stable, easy to fly and recovered well from spins.

However, even experienced test pilots found it difficult to hook the Goblin back onto the B-29’s trapeze, due to the airflow around the larger aircraft. The XF-85 program was terminated in mid-1949. The XF-85, although sound in theory, was too slow and too lightly armed to be an effective threat to enemy fighters; re-attaching the XF-85 to its trapeze proved much more difficult for pilots than anticipated, and the newly developed procedure of in-flight refueling gave more conventional fighters greatly extended range, undercutting the need for a parasite fighter that would be carried by a mother ship-bomber. A brief attempt was made to revive the parasite fighter concept using the F-84 Thunderstreak, a swept-wing version of the original Thunderjet, but this too proved less than feasible.

The XF-85 in a hangar with its wings folded, attached to the trapeze which lowered it out of the bomb bay of a B-29 in flight.

Specifications

Wingspan: 21 feet, 1.5 inches
Length: 14 feet, 11 inches
Height: 8 feet, 3 inches
Weight: 3,740 lbs. empty; 4,550 lbs. loaded
Armament: Four .50 caliber Browning M2 machine guns
Engine: Westinghous J34-WE7 turbojet of 3,000 lbs. thrust

Performance:

Maximum speed: 650 mph
Cruising speed: 580 mph
Maximum crusing time: 1 hour, 20 minutes
Service ceiling: 48,000 feet

The Kit

MPM’s XF-85 is molded in grey with delicated engraved panel lines and consists of 42 plastic and 16 photo-etch parts, together with three films for the instrument panel and a vacuform canopy. It comes with a dolly for the completed model to rest on, as well as the option for an extended or retracted trapeze hook in the upper nose. Photo-etch parts for the turbofan, cockpit instrument panel, individual controls, side walls, wing fences and wing fins add realistic detail. There are decals for both of the only two prototypes built, both in U.S. Air Force markings and based at Edwards Air Force Base in the Summer of 1948.

References

• United States Air Force Museum Guide Book (Wright-Patterson AFB publication)
• wikipedia.org