NATO reporting name: Freestyle

TYPE: Single-seat carrier-based V/STOL air combat fighter/attack aircraft.

PROGRAMME: Known previously in the West as Yak-41; authentic details released by Yakovlev OKB at 1991 Paris Air Show; project design started 1975; first flight of prototype March 1989; two prototypes accumulated 200 flying hours by June 1991; two others built for structural, systems and engine testing; claims for 12 international records submitted to FAI, including time-to-height with payload in STOL category; record attempts for speed in closed circuit planned; flight tests to continue until 1995; pre-production order awaited in mid-1991; intended initially to replace Yak-38 for air defence of 'Kiev' class carrier/cruisers, with secondary attack capability.

DESIGN FEATURES: Multi-engine lift/thrust configuration as Yak-38, but twin fins widely separated on flat-sided tailbooms, extending well beyond nozzle of propulsion engine, rectangular wedge engine air intake each side of fuselage, shallow 'fence' forward of each fin root, as on MiG-29 but longer, probably housing chaff/flare dispensers; bulged wingtips, probably for 'puffer-jet' stability control system.

FLYING CONTROLS: Triplex full-authority digital fly-by-wire control; all-moving horizontal tail surfaces; wing leading-edge flaps; remaining surfaces not yet verified.

STRUCTURE: Extensive use of aluminium/lithium; 26 per cent by weight carbonfibre composites, including wing flaps, slats, leading- and trailing-edges, and tail surfaces; sweptback wings fold upward at mid-span for stowage; model at Paris Air Show had wing leading-edge extension (also carbonfibre composites) on side of each intake duct, forward of wingroot.

LANDING GEAR: Retractable tricycle type with single wheel on each unit; nosewheel retracts rearward; mainwheels, on trailing-link legs, retract forward into engine ducts.

POWER PLANT: Primary power plant is Soyuz/Koptchyenko R-79 turbofan, rated at approx 88.25 kN (19,840 lb st) dry, 152.0 kN (34,170 lb st) with afterburning. Door beneath nozzle allows it to be vectored 65° downward for short take-off, 95° downward and forward for vertical landing. R-79 lift thrust is approx 80 per cent of cruise rating. Two vertically mounted RKBM/Rybinsk RD-41 liftjets, each approx 40.8 kN (9,170 lb st) immediately aft of cockpit in installation similar to that of Yak-38 liftjets; computerised engine control system.

ACCOMMODATION: Pilot only, under blister canopy. Flat bulletproof windscreen. Automatic ejection system for pilot in emergency during vertical and transition flight modes.

AVIONICS: Manual or automatic flight control from take-off to landing, day and night, in all weathers. Multi-mode fire-control radar similar to that of MiG-29, with slightly smaller antenna.

ARMAMENT: One 30 mm gun. At least four underwing hardpoinls for AA-10 (NATO 'Alamo') and/or AA-11 ('Archer') air-to-air missiles, bombs and rockets.

DIMENSIONS, EXTERNAL:

• Wing span: 10.10 m (33 ft 1¾ in)
• Width, wings folded: 5.90 m (19 ft 4¼ in)
• Length overall: 18.30 m (60 ft 0 in)
• Height overall: 5.00 m (16 ft 5 in)

WEIGHTS AND LOADINGS:

• Max external weapons load: 2,600 kg (5,730 lb)
• Max T-O weight, STOL: 19,500 kg (42,990 lb)

PERFORMANCE:

• Max level speed at height: 970 knots (1,800 km/h; 1,118 mph)
• Service ceiling: above 15,000 m (49,200 ft)
• Max range: internal fuel, vertical T-O: 755 nm (1,400 km; 870 miles)
• with external fuel, short T-O: 1,133 nm (2,100 km; 1,305 miles)

The article appears in the following publication:
Jane's All the World's Aircraft 1991-92. Jane's Information Group Ltd. 1991. ISBN: 0-7106-0965-5