This is the unique FICON (FIghter CONveyor) modification of the prototype Thunderflash, designed to operate as a parasite fighter from a mother-ship B-36 (in fact GRB-36F) using a trapeze mechanism. Whilst technically successful, the operation was very challenging even for experienced pilots with several near disasters while unhooking or recovering. After a number of RF-84Ks were trialled by SAC in 1955-56, the project was dropped. The aircraft is now displayed indoors in the 91st SRS markings carried in the mid-1950s