Yak-33 multi-purpose supersonic VTOL aircraft
In early 1960s the Yakovlev OKB embarked on projecting a family of aircraft collectively referred to as the Yakovlev Yak-33. Sharing a common airframe and differing in mission equipment, the family included a bomber, an interceptor and a reconnaissance aircraft. These were supersonic VTOL aircraft (a concept that, with the benefit of hindsight, may well be regarded as being ahead of its time). The aircraft were configured for high-speed low-altitude missions. One of the projects of this family, namely the bomber, was submitted as a contender in a competition for a supersonic strike bomber in 1962.
The Yakovlev Yak-33 was designed in several alternative basic layouts, some of which were rather unorthodox. These included a machine with high-set delta wings and a traditional tail unit, a tailless delta-wing aircraft with high-set wings, and a version with a canard layout.
The tailless-delta version was powered by two cruise engines placed side-by-side in the rear fuselage. These were presumably Kolesov RD36-41 afterburning turbofans with a nominal rating of 7,000 kgp (15,435 lbst) dry and a reheat (take-off) rating of 10,000-16,000 kgp (22,050-35,280 Lbst). On take-off the jetpipes would be diverted upstream of the afterburner to direct the jets downwards, thus helping to lift the aircraft. The cruise engines breathed through lateral air intakes (fashioned like those of the later Tu-22M3). They were to be supplemented by six to eight lift engines placed between the air intake ducts and delivering a thrust of 3,000 kgp (6,610 lbst) apiece. The bomber’s armament comprised the Kh-45 anti-shipping missile with a range of 1,500 km (932 miles), which was under development at MKB Raduga ( Rainbow’ Machinery Design Bureau), and various free-fall bombs.
The alternative version featuring a canard layout was rather unorthodox in its powerplant arrangement. Two RD36-41 cruise engines (with thrust-vectoring nozzles, as above) were accommodated in nacelles attached to the tips of a delta wing; the same nacelles, measuring 9.88 m (32 ft 5 in) in length, also housed two lift engines each. In addition, a pair of lift engines was accommodated in the fuselage amidships, behind the canard foreplanes. Both this and the preceding version featured a bicycle undercarriage with outriggers placed at the wingtips and retracting into special fairings (in the case of the tailless-delta layout) or into the engine nacelles (in the case of the canard layout). In all versions the crew comprised a pilot and a navigator seated in tandem in a pressurised cockpit.
The dimensions and some design performance figures for the bomber version of the Yak-33 in the tailless delta configuration are as follows (figures for the canard layout version are given in the brackets): Length 26.375 m/86ft 6 in (27.0 m/88 ft 7 in); wing span 10.25 m/33 ft TA in (11.1 m/36 ft 5 in). Normal take-off weight in both cases was 32,000 kg (70,560 lb) and maximum take-off weight up to 40,000 kg (88,200 lb); the lift engines in both cases were eight 3,000-kgp turbojets. Maximum and cruising speed, as stipulated by the operational requirements, were Mach 3 and Mach 2 respectively in both cases; specified range in both cases was 4,000 km (2,486 miles).