Republic XF-91 Thunderceptor
The Republic XF-91 Thunderceptor is a mixed-propulsion prototype interceptor aircraft, developed by Republic Aviation. The aircraft would use a jet engine for most flight, and a cluster of four small rocket engines for added thrust during climb and interception. The design was largely obsolete by the time it was completed due to the rapidly increasing performance of contemporary jet engines, and only two prototypes were built. One of these was the first American fighter to exceed Mach 1 in level flight.
Republic XF-91 Thunderceptor
XF-91 in 1951 at Edwards Air Force Base.
XF-91 Thunderceptor during testing
On the left is Republic XF-91 (serial number 46-680) after the nose radome installation and on the right is XF-91 (serial 46-681) after the V-tail modification.
An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically for the defensive interception role against an attacking enemy aircraft, particularly bombers and reconnaissance aircraft. Aircraft that are capable of being or are employed as both ‘standard’ air superiority fighters and as interceptors are sometimes known as fighter-interceptors. There are two general classes of interceptor: light fighters, designed for high performance over short range; and heavy fighters, which are intended to operate over longer ranges, in contested airspace and adverse meteorological conditions. While the second type was exemplified historically by specialized night fighter and all-weather interceptor designs, the integration of mid-air refueling, satellite navigation, on-board radar and beyond visual range (BVR) missile systems since the 1960s has allowed most frontline fighter designs to fill the roles once reserved for specialised night/all-weather fighters.
The Convair F-106 Delta Dart, a principal interceptor of the U.S. Air Force in the 1960s, 70s, and 80s
A USAF F-22 Raptor air superiority fighter intercepting a Russian Tu-95 near Alaska
RAF English Electric Lightning point defense interceptor
Mikoyan MiG-31