Republic XF-103

The Republic XF-103 was a 1950s proposal for a high-altitude, high-speed interceptor to counter soviet bombers. The XF-103 comprised many novel features for its time. It was to be primarily constructed from Titanium (Almost a decade before the A-12). The proposed armament was to be 6 Hughes GAR-3 Falcon air-to-air missiles. Most interesting of all was the planned mixed propulsion, a Wright XJ67-W-1 turbojet along with a Wright XRJ55-E-1 ramjet, propelling the aircraft to Mach 3+ at 80,000 feet.

General Specifications:

Crew - 1
Wingspan - 35' 10"
Length - 75' 2"
Height - 18' 4"
Projected speed - 2600 mph

The XF-103 would never be more than a mockup. The steady increase in projected weight, ballooning costs and, multiple delays eventually culminated in the cancelation of the project in 1957.