MiG21PD / Уе-7РП / 23-31 / ТірШ

This experimental STOL aircraft was designed to assess the MiG-21’s operational capabilities on short strips. A MiG-21 PFM airframe was equipped with one R-13F-300 turbojet rated at 6,360 daN (6,490 kg st) and two Kolyesov RD-36-35 lift jets that were set slightly forward near the aircraft’s center of mass. This forced the engineers to add a fuse­lage ‘‘slice" 900 mm (35.43-inches) thick just behind the cockpit; the master cross-section became appreciably larger where the lift jets were installed. They were fed in air by a rearward-hinged door with louvers that was opened by an actuator at takeoff and landing. The action of the lift jets was limited to reducing the aircraft’s ground roll. They were never operated in flight, and the inlet door was kept shut. The fixed tricycle gear had a wider wheel track.

The MiG-21 PD (Podyomnye Dvigatyeli: lift jet) was first piloted on 16 June 1966 by P. M. Ostapyenko. B. A. Orlov took over for the facto­ry tests, which ended in 1967. The aircraft made its public debut at

the Domodyedovo air show in July 1967 There proved to be fewer pros to this STOL prototype than cons, so the aircraft’s development was discontinued.

Specifications

Span, 7.765 m (25 ft 5.7 in); fuselage length (except cone and probe), 12.3 m (40 ft 4.3 in); wheel track, 3.4 m (11 ft 1.9 in); wheel base, 5.15 m (16 ft 10.7 in).