Whoever thought that attaching two B-47s to a B-36 was a good idea is a detail that seems to have been lost to time… perhaps the notion came from Boeing, perhaps Convair, perhaps the Air Force, perhaps someone at the NACA
As bombers gained greater range, they soon exceeded the distance any practical fighter escort could cover. Before the long‑range P‑51D was available to accompany B‑17s and B‑24s over Europe, many bombing raids suffered devastating losses of aircraft and crews because they lacked adequate protection. Once bombers reached truly intercontinental ranges, escorting them with fighters became essentially impossible in the early jet era, since the bombers themselves were largely flying fuel tanks. This led to growing interest in the concept of attaching “parasite” fighters to bombers—small fighters that would be carried along and deployed only when needed deep inside enemy territory.
As Scott Lowther describes in his book Boeing B-47 Stratojet & B-52 Stratofortress Origins and Evolution, Wright Field carried out practical flight trials in the late 1940s by modifying the wingtip of a C-47 cargo aircraft so it could connect to a single Q-14 Culver Cadet. Predictably, early tests starting in August 1949 revealed challenges in figuring out how to link the two planes wingtip to wingtip. However, these issues were eventually resolved, and by late 1950 the pair had logged more than 28 hours of connected flight across hundreds of missions.
These experiments led to project MX-1018, which tested mounting a Republic EF-84D jet fighter on each wingtip of an ETB-29A. Flight trials began in July 1950 and continued until April 1953, when one EF-84D attached to the bomber’s left wing suddenly pitched up, flipped over onto the bomber’s wing, and caused a disaster. The fighter’s nose and the bomber’s outer wing were torn off, and both aircraft crashed, killing all crew members and bringing the project to an end. During earlier tests, however, engineers discovered that the jet fighters could throttle back to idle or even shut down entirely while the combined aircraft still flew smoothly. The system was, by design, never operated in turbulent conditions.
After MX-1018 came the “Tom-Tom” project, which followed a similar idea but used two swept-wing Republic RF-84F fighters attached to the wingtips of a modified Convair RB-36F. Flight tests started in 1955 and continued into 1956, ending when one of the RF-84Fs began to oscillate violently, soon damaging the coupling mechanisms between the aircraft. In this instance, all planes landed safely, but the program was still canceled. Once again, trials showed aerodynamic advantages for the B-36, but persistent difficulties with mid-air coupling. The goal of “Tom-Tom” was to provide the B-36 with two escort fighters for its long missions over enemy territory. How enthusiastic the fighter pilots were about spending nearly two days in cramped cockpits (given that the B-36 could stay aloft for about 40 hours) is not well recorded.
While these projects were in progress, NACA was assigned to analyze the idea of a B-36 carrying a B-47 on each wingtip. Who originally thought attaching two B-47s to a B-36 was sensible is unclear—whether it came from Boeing, Convair, the Air Force, or someone at NACA has been lost to history. In any case, very little design data survives. The only NACA report shows just the wing planform, without further specifics. The configuration recreated here is therefore tentative and is depicted using wingtip docking hardware based on the Tom-Tom program.
For several reasons, this combined aircraft probably would not have taken off with all components already joined. To begin with, when the assembly was level, the B-47s sat so high that their landing gear would not have touched the runway while the B-36 was still rolling. At low speeds, the B-47s would have tipped over significantly, possibly enough for their outer wingtips to scrape the ground. Additionally, the 462-foot wingspan posed a serious problem: very few runways are wide enough to accommodate landing gear spaced that far apart.
This aircraft was most likely intended to extend the B-47s’ range. The B-36 would carry the B-47s, with their engines idling, from the United States to a point near Soviet airspace. The B-47s would then separate and head for their targets, with fuel tanks full or nearly full, allowing them to strike deep inside enemy territory. The B-36 would then likely return to base, having traded its own internal bomb load for additional fuel tanks to support the mission.
At least the B-47 crews would have been able to stand up and walk around, unlike the Tom-Tom F-84 pilots. Even so, the concept appears to have been short-lived.
Boeing B-47 Stratojet & B-52 Stratofortress Origins and Evolution is published by Mortons Books and is available to order here.
Photo by: U.S. Air Force
