At the end of 1951, the MiG OKB had completed an
adaptation of the MiG-17 airframe for a pair of
2600kg Mikulin AM-5 turbojets as the
Izdeliye SM-1, or I-340. Purely an engine test bed, the
SM-1 had demonstrated the efficacy of the side-by-side
installation of the small-diameter turbojets, achieving
speeds of 1193km/h at 1000m and
1154km/h at 5000m, an altitude
attained in 0.94 min.
The success achieved with the SM-1 determined choice of engine and power plant
arrangement for the SM-2 single-seat fighter proposal
embodying an essentially similar wing to that of the
I-350 with 55° sweepback at quarter chord (60°
at leading edge). Powered by two AM-5F turbojets
each with an afterburning rating of 2700kg and having an armament of two 37mm
N-37D cannon in the wing roots, the first SM-2 - by now
assigned the official designation of I-360 - was flown on
24 May 1952. This was unique in having a T-type horizontal
tail, and, on 25 June, it attained Mach=1.04 in
level flight. Subsequent testing revealed that the wing
tended to blanket the tailplane at high angles of attack,
and, to rectify this deficiency, the tailplane was
lowered to a mid point on the fin. Flight test (as the
SM-2A) revealed little improvement and the surface
was then further lowered to the base of the fin (as the
SM-2B), this being accompanied by some increase in the vertical tail surface area, and satisfactory handling
characteristics resulting. Nonetheless, the prototype
was lost on its 132nd flight as a result of tail flutter. It
was calculated that the maximum attainable Mach
number of the fighter was 1.19, but no details of performance
are available.
