The Air Force will try just about anything once.

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.^[1][2] The Tip Tow aircraft consisted of a specially modified ETB-29A (serial number 44-62093) and two EF-84B(serial numbers 46-641 and 46-661). 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 2hr 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.