The McDonnell Aircraft Corp. developed the XF-85 Goblin "parasite" fighter to protect B-36 bombers flying far beyond the range of conventional escort fighters. The "parent" B-36 would carry the XF-85 within a bomb bay -- if enemy fighters appeared, the Goblin would be lowered on a trapeze and released to combat the attackers. Once the enemy had been driven away, the Goblin would return to the B-36, reattach to the trapeze, and be lifted back into the bomb bay.

Two test aircraft were ordered in October 1945, and flight testing with a modified B-29 began in 1948. Test pilots could successfully launch the XF-85, but the turbulent air under the B-29 made recovery difficult and hazardous. About half of the Goblin flights ended with emergency ground landings after the test pilot could not hook up to the B-29.

No XF-85s were ever launched or carried by a B-36. The program ended in late 1949 when aerial refueling of conventional fighter aircraft showed greater promise. The XF-85 was transferred to the museum in 1950.