XF-85 Goblin

YouTube – XF-85 Goblin

Primary Function:
Weight Empty:
Max. Weight:
Machine Guns:
Wingspan Folded:
Cruise Speed:
Max. Speed:
Climb Rate:
Year Deployed:
Westinghouse XJ-34
3,000 lbs.
4,550 lbs.
5,600 lbs.
4 – .50 cal.
14 ft. 10 in.
21 ft. 1 in.
5 ft.
8 ft. 4 in.
480 mph
648 mph
12,500 fpm
48,000 feet
779 miles

The XF-85 Goblin, produced by McDonnell, is the world’s smallest fighter jet.  It was developed as a result of the success of long range bomber escort fighter aircraft.

When transcontinental range bombers were to be introduced, and before mid air refueling, the only way to have full time fighter escorts was for them to be carried by “mother ships.”

The XF-85 Goblin was intended as an escort fighter that would be carried and launched by bombers on long missions.

In March of 1947 the U.S. Air Force contracted with the McDonnell to produce two prototype aircraft.

The XF-85 Goblin, after flying its mission, was expected to return to the host aircraft using a hook and trapeze. It had skids instead of landing gear. These were to be used in case it couldn’t be recovered by the host bomber and had to make a forced landing. The aircraft had folding wings in order to fit into the “mother ship.”

Test pilots reported that the aircraft was easy to fly. A big problem, however, was that the tiny aircraft had alignment difficulties with the recovering aircraft’s trapeze due to wake turbulence. Docking with the mother ship was virtually impossible.

Even the best test pilots had a hard time flying the aircraft back to the mother ship and reattach it to the trapeze. Therefore it would be almost impossible for other pilots to perform the operation.

The advancements of aircraft at that time also showed that the XF-85 Goblin would soon not be able to perform to their standards in the areas of maneuverability and supersonic flight.

Standard fighters would soon be able to escort bombers on long missions using mid air refueling. Congress was also reducing the budgets of the armed services from war time funding levels.

The XF-85 Goblin project was ended on October 24, 1949.

rc XF-85 Goblin

XF-85 Goblin

We received the following email with the picture just above from Petronio Aznar Artero ([email protected]) He writes: “Well, my friend Juan Pedro somehow talked me into building a PSS model and I just ended up choosing the XF-85 Goblin.  It’s probably one of those models you either hate or love…I love it! (otherwise I wouldn’t spent time and money on building twice the same real bird..). I know it is definitely not a good chosen subject as a PSS but just assume the risks..To be honest I have grown tired throughout the last years of always seeing the same airplanes in the flying fields so I am very fond of people building original and less seen models. I have still parked somewhere in a CAD folder my 62cc gaser project.. I have seen some people building an XF-85 Goblin, amongst them John Boren with whom I had some email correspondence, but the ones I have seen starting the project I have not seen finishing it, so at least as far as I know if I get the XF-85 Goblin EDF to fly it will be the first one; the PSS version is the first and only one worldwide no doubt).

Specs are as follows:
XF-85 Goblin PSS:
length: 855 mm (23.1 in.)
wingspan: 1532 mm (60.3 in)
weight: 1.9 kg (4.1 lbs) worrying!?!
Airfoil: S-3021

About construction of the XF-85 Goblin, well you know, balsa built up tail feathers, fuselage are foam slices glued together with one fiberglass layer (very front and aft are balsa), canopy also homemade (took some tries as rather big), wings are sheeted foam cores. Controls include ailerons and fully movable elevators, no rudder. The whole model was covered with Chrome Oracover (because of weight issues no flite-metal or painting).

About the PSS model XF-85 Goblin, though just started, fuse is built the same way, just that I had to obviously redesign all templates as I had to accommodate all the electronic equipment, tail feathers built the same way but slightly lighter (so many tail feathers have a tremendous effect on CG!), also fully functional and movable elevators (this time carbon stick will not be seeable through the duct but horn will go in the fuselage wall (pics to come)), the XF-85 Goblin will have a (hidden?) pneumatic retract landing gear (no grass where I live!!..you know that too :)), with 92 mm Fan and a planned Zippy 6S5000 mAh lipo battery on the belly (hole already cut to size hopefully if the specs in the shop were correct hehe). Not really interested in speed, all I want is a scale looking FLYABLE model :)!”

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