FICON project

The FICON (Fighter Conveyor) program was conducted by the United States Air Force in the 1950s to test the feasibility of a Convair B-36 Peacemaker bomber carrying a Republic RF-84K Thunderflash parasite fighter in its bomb bay. Earlier wingtip coupling experiments included Tip Tow, which were attempts at carrying fighters connected to the wingtips of bombers. Tom-Tom followed the FICON project afterwards.

Wingtip coupling experiments were evolved from the concept of adding extra floating panels to extend the effective wingspan of an aircraft, in the hope this would extend the range of the aircraft. This would theoretically act in the same manner as the long narrow wings of a glider. It is reported that the Germans experimented with the idea in 1944 and 1945 by coupling two equal-sized light planes together, then the idea was further developed by Dr. Richard Vogt who came to the US from Germany after World War II. The idea was tested at Wright Field in the late 1940s using a Douglas C-47A Skytrain and Culver Q-14B Cadet. These tests showed the idea had promise, and Republic Aviation was awarded a contract to investigate further. Thus began the Tip Tow project.

The MX-1018 program (code named "Tip Tow") sought to extend the range of the early jets in order to give fighter protection to piston-engined bombers with the provision for in-flight attachment/detachment of the fighter to the bomber via wingtip connections. The Tip Tow aircraft consisted of a specially modified ETB-29A (serial number 44-62093) and two EF-84D (serial numbers 48-641 and 48-661). A number of flights were undertaken, with several successful cycles of attachment and detachment, using at first a single aircraft, and then two. The pilots of the F-84s maintained manual control when attached, with roll axis maintained by elevator movement rather than aileron movement. Engines on the F-84s were shut down in order to save fuel during the "tow" by the mother ship, and in-flight engine restarts were successfully accomplished.

Wing flexibility of the B-29 as well as wing-tip vortices caused concern, and the mechanisms for attachment required modifications. The first hookup of both F-84s with the B-29 occurred on the 10th flight on 15 September 1950. The longest flight with all connected was on 20 October 1950, and lasted for 2h 40min. All of these flights were accomplished with manual control of the F-84 aircraft. Republic received an additional contract to continue the experiments by incorporating an automatic flight control system. Meanwhile, as the modifications proceeded, additional test flights were made, including night flights. The automatic flight control modifications were ready for testing in March 1953, and a number of hookups were made with only one or the other of the F-84s while attempting to sort continuing electrical issues. On 24 April 1953, the left-hand F-84 hooked up and the automatic system was activated. The F-84 immediately flipped over onto the wing of the B-29 and both crashed with loss of all on board.

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