Early jet fighters had limited range and endurance, and several bizarre experiments were performed during the late 1940s and early 1950s to test the feasibility of enhancing jet fighter range by having them carried into the combat zone by either being towed behind bombers or by being stowed inside them. None of these range-extension experiments was more bizarre than "Project TOM-TOM", in which jet fighters were to be attached to the wingtips of large bombers such as B-29s or B-36s.
Two F-84Bs (46-641 and 44-661) were selected and modified for the initial tests. These two F-84Bs were redesignated EF-84B. The wingtips of the EF-84Bs were modified so that they could be attached to flexible mounts fitted to the wingtips of a specially modified EB-29A (serial number 44-62093). I have a photograph of this bizarre three-plane arrangement flying wingtip-to-wingtip, and you have to blink your eyes a couple of times to make sure that they are not fooling you.
As expected, this idea proved to be highly dangerous. The biggest problem was the extreme vortex that was generated at the wingtips of the EB-29A, which caused the attached parasites to roll violently. The entire three-plane EF-84B/EB-29A/EF-84B array crashed as a unit on April 24, 1953, killing all the crewmembers. The project was terminated shortly thereafter.
A parallel project had been undertaken with a pair of RF-84Fs (51-1848 and 51-1849) attached to wingtip hook-up assemblies on an RB-36F (49-2707). This particular RB-36F had been used in the FICON project and was reassigned to TOM-TOM. The RB-36F had articulated hookup arms attached to the wingtips, and the two RF-84Fs had articulated clamp assemblies on their wingtips. Tests began in mid 1952, and the first actual hook-ups were made in early 1953 with just one of the RF-84Fs. After the crash of the EB-29A/EF-84B combo, trials continued for a few months with this RF-84F/RB-36F/RF-84F array. Only a few hookup attempts were actually made, and wingtip vortices and turbulence always made this operation a very dangerous and difficult affair. Many times, hook-up attempts had to be aborted because of turbulence and wingtip vortices. In late 1953, an RF-84F flown by Convair test pilot Beryl Erickson was torn free from the B-36's wing. Although the RF-84F managed to land safely, the Convair team concluded that it was too dangerous to continue and decided to halt the program. A month later, the Air Force officially cancelled the TOM-TOM program. At this time, experiments with mid-air refuelling techniques seemed to offer greater promise for increased fighter ranges with far less risk to the lives of aircrews. All three aircraft were de-modded and reverted to their original configurations.