Convair QF-106 Delta Dart

Under the 1954 interceptor program the USAF, primarily Air Defense Command (ADC), put out a request for proposals for upgraded, single seat, super sonic interceptor aircraft.  At this time the ADC, primarily in charge of defending the United States from an airborne invasion, was obsessed with the concept of high speed interceptors for combating waves of incoming Russian bombers (which never really existed in large quantities).  The winner of the program was the Convair F-102 Delta Dagger which was mostly considered a large disappointment.  Continuous upgrades to the F-102 eventually turned into an entirely new aircraft, being designated the F-106.  The Delta Dart was the ADC’s “ultimate interceptor”, also its last.  

Under Operation Highspeed, the USAF was asked to compare its F-106 with the U.S Navy F4H-1 Phantom (F-4 Phantom ii), in an effort to combine branch resources.  Since the F-4 was as capable an interceptor as the F-106 and able to perform multiple other missions (bombing, dogfighting, etc.) the F-4 was chosen to be the primary USAF fighter, ultimately leading to the F-106 never seeing combat over the skies of Vietnam.  

F-106’s continued service in the ADC as a defensive interceptor and eventually was converted into a drone for aerial target practice, pictured above.