YF-94 TF-80Cs converted into YF-94 prototypes, two built.[18] F-94A Initial production version, 109 built.[18] YF-94B One F-94A modified on the production line with new flight director, modified hydraulic systems, and two enlarged wingtip tanks.[18] F-94B Production model based on YF-94B, 355 built.[18][19][nb 1] YF-94C F-94Bs modified with Pratt and Whitney J48 engine, leading edge rocket pods, and swept tailplane, originally designated YF-97A, two modified. F-94C Starfire Production version of the YF-94C with longer nose, gun armament replaced with nose mounted rockets, and provision for underfuselage JATO rockets, originally designated F-97A, 387 built.[21] EF-94C Test aircraft for proposed reconnaissance variant YF-94D Prototype single-seat close support fighter version based on the F-94C, one partly built but construction was abandoned when program was cancelled. F-94D Production version of the YF-94D, 112 on order cancelled, none built.[22] YF-97A Original designation of the YF-94C.