Yakovlev Yak-55 - Development

Development

The Soviet team in the 1976 World Aerobatic Championship, although dominating the championship, finishing first and second in the individual competition and also winning the team and women's competitions in their Yakovlev Yak-50s, were impressed by the performances of competing foreign aircraft which could carry out the required manoeuvers in less space than the Yak-50. A team in the Yakovlev design bureau, lead by Sergei Yakovlev, and with V.P. Kondratiev and D.K. Drach as chief engineers, therefore set out to design an all new dedicated aerobatic aircraft, unrelated to the Yak-50, which would be able to match the tight, low-speed style of Western aircraft.

The resulting design, the Yakovlev Yak-55, was a single-engined all-metal cantilever monoplane. The aircraft's wing is mounted mid-way up the fuselage and is of thick, symmetrical section to aid inverted flight. The pilot sits in an enclosed cockpit under a sliding teardrop canopy level with the trailing edge of the wing and with the seat below wing level. The powerplant is the same tractor configuration 360 horsepower (270 kW) Vedeneyev M14P engine driving a two-bladed V-530TA-D35 propeller, as used by the Yak-50, while the aircraft has a fixed undercarriage with titanium sprung main gear and tailwheel.

The prototype Yak-55 first flew in May 1981 and was unveiled at the Moscow Tushino air show in August 1982, and was displayed (but did not compete) at the 1982 World Aerobatic Championships. By this time, fashions in aerobatic flying had changed, with the high energy aerobatics demonstrated by the Yak-50 back in fashion, leading to the Yak-55 being rejected by the Soviet team. The Yak-55 was therefore redesigned, with new wings, with shorter span, reduced area and a thinner but still symmetrical aerofoil section, giving an increased rate of roll and speed. Series production finally began in 1985 at Arsenyev, with 108 aircraft being delivered by 1991.

In the late 1980s, work began on a revised version of the Yak-55, the Yak-55M, to meet demands from DOSAAF for an aircraft with further increased rates of roll, and to compete with new designs from the Sukhoi design bureau. The Yak-55M had a still smaller wing, which resulted in the required improvement in roll-rate. It first flew in May 1989, entering production in 1990. 106 Yak-55Ms had been built by the end of 1993, with low rate production continuing.