Jun 072014
An illustration of the proposed RF-4X from the early 1970s. This was to be a highly modified version of the F-4E Phantom II capable of attaining Mach 3 for short periods. This would be possible by used more advanced inlets with water injection for pre-compressor cooling. The water would be stored in conformal tanks above the fuselage. The RF-4X would be a recon platform for the Israelies, sort of a low-budget, less stealthy SR-71.
More on the RF-4X HERE.