During 1961, the MiG OKB initiated work on an upgraded fighter based on the basic MiG-21PF airframe and referred to contemporaneously as the MiG-23. Assigned the OKB designation Ye-8, it featured a bifurcated ventral air intake for the R-21F engine, which, developed by N Metskhvarishvili, was rated at 4500kg and 7000kg with afterburning. A variable-incidence canard spanning 2.60m was fitted - this having been earlier tested by a Ye-6T - and it was proposed to install Sapfir 21 radar to accompany an armament of two K-13 AAMs. The first of two prototypes, the Ye-8/1, was flown on 17 April 1962, followed on 29 June by the Ye-8/2. On 11 September, the R-21F engine of the Ye-8/1 exploded at Mach=1.7 at 10000m. It was subsequently ascertained that the sixth compressor stage fan had penetrated the engine casing and had then continued on to destroy the starboard aileron. At this time, the Ye-8/2 had effected 13 flights, but the programme was abandoned.
Max take-off weight: 8200 kg / 18078 lb
Wingspan: 7.15 m / 23 ft 5 in
Length: 14.90 m / 48 ft 11 in
Wing area: 23.13 sq.m / 248.97 sq ft
Max. speed: 2230 km/h / 1386 mph
Ceiling: 20000 m / 65600 ft