Art Model AM 7208 Mikoyan-Gurevich MiG-23PD Soviet Experimental STOL Fighter

Mikoyan-Gurevich MiG-23PD Soviet Experimental STOL Fighter

In early December 1963, the Soviet government formally authorized the development of a next-generation tactical fighter. Driven by Soviet Air Force requirements for a combat aircraft capable of operating from short, austerely equipped, or damaged airstrips, the program prioritized short take-off and landing capabilities. To meet this demanding specification, the Mikoyan-Gurevich design bureau pursued two parallel design tracks: a variable-geometry design (Project 23-11) and a lift-plus-cruise configuration.

Initial flight testing of the lift-jet concept utilized a modified production MiG-21S. Designated internally as Izdeliye 23-31 (also known as the Ye-7PD), this flying testbed featured a 35.4-inch fuselage plug inserted behind the cockpit to house a pair of vertical lift engines. The modified aircraft made its maiden flight on June 16, 1966.

Meanwhile, construction of the dedicated prototype, designated 23-01 (tactical number 23), began in March 1966 and was completed in eight months. Unlike the modified MiG-21, this was an entirely new airframe featuring semi-circular lateral air intakes, a configuration that freed the nose section to accommodate a powerful intercept radar. Aerodynamically, the wing and tail surfaces retained the MiG-21's configuration, preserving the mid-mounted delta wing with a 57-degree leading-edge sweep, although its area was increased by 73.6% to 430.56 sq ft.

The aircraft utilized a mixed powerplant configuration. Forward propulsion was provided by a Tumansky R-27F-300 afterburning turbojet, rated at 11,464 lbf dry and 17,196 lbf in afterburner. Vertical lift augmentation was supplied by a pair of Kolesov RD-36-35 lift jets, each producing 5,181 lbf, installed vertically in the center fuselage behind the cockpit, near the center of gravity. Intake air for these auxiliary engines was fed through a dorsal louvered door, while the exhaust was directed through ventral transverse louvers capable of vectoring the thrust rearward to aid in ground acceleration. The lift jets were operated strictly during the take-off and landing phases. To further reduce the take-off run, high-pressure bleed air from the main engine's compressor was ducted over the flaps for boundary layer control. The combination of vectored thrust and flap blowing reduced the ground roll to 590–656 ft.

Test pilot Pyotr Ostapenko conducted the maiden flight of the 23-01 on April 3, 1967. On July 9 of the same year, the aircraft publicly demonstrated its short-field capabilities at the Domodedovo air show. Although the design specifications included an internal 23 mm GSh-23 cannon and K-23 medium-range air-to-air missiles, the flying prototype was unarmed, carrying instrumentation and telemetry equipment in the nose instead of a targeting complex.

Flight trials, which concluded in the autumn of 1967, revealed the operational limitations of this configuration. The lift engines consumed critical internal fuselage volume, drastically reduced fuel capacity and weapon payload, and acted as deadweight during cruise flight. Consequently, development of the 23-01 was terminated, and all resources were redirected to the parallel variable-geometry project, the Mikoyan-Gurevich MiG-23-11.

Technical Specifications of the Mikoyan-Gurevich MiG-23PD

• Length — 55.12 ft
• Wingspan — 25.33 ft
• Wing area — 430.56 sq ft
• Maximum take-off weight — 40,785 lb
• Powerplant — 1 × R-27F-300 afterburning turbojet (17,196 lbf), 2 × Kolesov RD-36-35 auxiliary lift turbojets (5,181 lbf each)
• Maximum speed — 994 mph
• Service ceiling — 66,601 ft
• Crew — 1
• Projected armament — 1 × 23 mm GSh-23 autocannon, 2 × K-23 medium-range air-to-air missiles (1 × semi-active radar-guided K-23R and 1 × infrared-homing K-23T)