NATO reporting name: Clobber

TYPE: Three-turbofan short/medium-range passenger transport.

PROGRAMME: Three prototypes ordered initially; first prototype (SSSR-1974) flew 7 March 1975, with 11° wing sweepback and furnished in 100-seat local service form, with carry-on baggage and coat stowage fore and aft of cabin; second prototype (SSSR-1975) had 23° sweepback and more cabin windows, representative of 120-seat version with three more rows of seats and no carry-on baggage areas; third prototype (SSSR-1976, later SSSR-42303) introduced small refinements (described in previous editions of Jane's): flight testing proved 23° wing superior; first series of production aircraft, built at Smolensk to replace some Aeroflot Tu-134s, generally similar to SSSR-42303 as exhibited 1977 Paris Air Show; changes for production included substitution of four-wheel main landing gear bogies for twin-wheel units on prototypes; scheduled service on Aeroflot's Moscow-Krasnodar route began late 1980.

VARIANTS: Yak-42: Basic standard, described in detail; Aeroflot had 72 in Autumn 1990.
Yak-42D: Increased fuel and rearranged interior; range increased to 1,185 nm (2,200 km; 1,365 miles) with 120 passengers; about 20 delivered by early 1991; production 15 a year, to continue five more years.
Yak-42E-LL: Test bed for D-236 propfan.
Yak-42M: See separate entry (Jane's 1991-92).

CUSTOMERS: 100 built by Autumn 1990, mostly for Aeroflot; two each for Cubana and China.

DESIGN FEATURES: Basic design objectives simple construction, reliability in operation, economy, and ability to operate in remote areas with widely differing climatic conditions; design is in accordance with Soviet civil airworthiness standards and US FAR 25; engines conform with international smoke and noise limitations, and aircraft is intended to operate in ambient temperatures from -50°C to +50°C; APU for engine starting and services removes need for ground equipment.
Conventional all-swept low-wing configuration; two podded turbofans on sides of rear fuselage, third in extreme rear fuselage with intake at base of fin; no wing dihedral or anhedral; sweepback 23° at quarter-chord; basically circular fuselage, blending into oval rear section; T tail.

FLYING CONTROLS: Hydraulically actuated; two-section ailerons, each with servo tab on inner section, trim tab on outer section; two-section single-slotted trailing-edge flap, three-section spoiler forward of outer flap, full-span leading-edge flap on each wing; one-piece variable-incidence tailplane, variable from 4° up to 8° down; trim tab in each elevator, trim tab and spring servo tab in rudder.

STRUCTURE: All-metal; two-spar torsion box wing structure; riveted, bonded and welded semi-monocoque fuselage.

LANDING GEAR: Hydraulically retractable tricycle heavy-duty type. Four-wheel bogie main units retract inward into flattened fuselage undersurface. Twin nosewheels retract forward. Hydraulic backup system for extension only. Emergency extension by gravity. Oleo-nitrogen shock absorbers. Steerable nose unit of levered suspension type. Low pressure tyres; size 930 x 305 mm on nosewheels. Hydraulic disc brakes on mainwheels. Nosewheel brakes to stop wheel rotation after take-off.

POWER PLANT: Three Zaporozhye/Lotarev D-36 three-shaft turbofans, each rated at 63.74 kN (14,330 lb st). Centre engine, mounted inside rear fuselage, has S-duct air intake. Outboard engines are mounted in pod on each side of rear fuselage. No thrust reversers. Integral fuel tanks between spars in wings, capacity approx 23,175 litres (6,120 US gallons; 5,100 Imp gallons).

ACCOMMODATION: Crew of two side by side on flight deck, with provision for flight engineer if required, and two or three cabin attendants. Single passenger cabin, with total of 120 seats in six-abreast rows, at pitch of 75 cm (29.5 in), with centre aisle, 45 cm (17.7 in) wide, in high-density configuration. Alternative 104-passenger (96 tourist, eight first class) local service configuration, with carry-on baggage and coat stowage compartments fore and aft of cabin. Main airstair door hinges down from undersurface of rear fuselage. Second door forward of cabin on port side, with integral airstairs. Service door opposite. Galley and crew coat stowage between flight deck and front vestibule. Passenger coat stowage and toilet between vestibule and cabin. Second coat stowage and toilet at rear of cabin. Two underfloor holds for cargo, mail and baggage in nets or standard containers, loaded through a door on the starboard side, forward of wing. Chain-drive handling system for containers built into cabin floor. Forward hold accommodates six containers, each with capacity of 2.2 m³ (77.7 cu ft); rear hold takes three similar containers. Provision for convertible passenger/cargo interior, with enlarged loading door on port side of front fuselage. Two emergency exits overwing on each side. All passenger and crew accommodation pressurised and air-conditioned, and furnished with non-flammable materials.

SYSTEMS: APU standard, for engine starting, and for power and air-conditioning supply on ground and, if necessary, in flight.

AVIONICS: Flight and navigation equipment for operation by day and night under adverse weather conditions, with landings on concrete or unpaved runways in ICAO Category II weather minima down to 40 m (131 ft) visibility at 300 m (985 ft). Type SAU-42 automatic flight control system and area navigation system standard.

DIMENSIONS, EXTERNAL:

• Wing span: 34.88 m (114 ft 5¼ in)
• Wing aspect ratio: 8.11
• Length overall: 36.38 m (119 ft 4¼ in)
• Fuselage diameter: 3.80 m (12 ft 5½ in)
• Height overall: 9.83 m (32 ft 3 in)
• Tailplane span: 10.80 m (35 ft 5 in)
• Wheel track: 5.63 m (18 ft 5¾ in)
• Wheelbase: 14.78 m (48 ft 6 in)
• Passenger door (fwd):
• Height: 1.81 m (5 ft 11¾ in)
• Width: 0.83 m (2 ft 8½ in)
• Passenger entrance (rear): Height: 1.78 m (5 ft 10 in)
• Width: 0.81 m (2 ft 7¾ in)
• Cargo door (convertible version):
• Height: 2.025 m (6 ft 7¾ in)
• Width: 3.23 m (10 ft 7 in)
• Baggage/cargo hold door: Height: 1.35 m (4 ft 5 in)
• Width: 1.145 m (3 ft 9 in)
• Height to sill: 1.45 m (4 ft 9 in)

DIMENSIONS, INTERNAL:

• Cabin: Length: 19.89 m (65 ft 3 in)
• Max width: 3.60 m (11 ft 9¾ in)
• Max height: 2.08 m (6 ft 9¾ in)
• Baggage compartment volume (100-seater):
• fwd: 19.8 m³ (700 cu ft)
• rear: 9.5 m³ (335 cu ft)

AREAS:

• Wings, gross: 150 m² (1,615 sq ft)
• Vertical tail surfaces (total): 23.29 m² (250.7 sq ft)
• Horizontal tail surfaces (total): 27.60 m² (297.1 sq ft)

WEIGHTS AND LOADINGS:

• Weight empty, equipped:
• 104 seats: 34,555 kg (76,180 lb)
• 120 seats: 34,580 kg (76,236 lb)
• Max payload: 13,000 kg (28,660 lb)
• Max fuel: 18,500 kg (40,785 lb)
• Max T-O weight: 56,500 kg (124,560 lb)
• Max landing weight: 50,500 kg (111,333 lb)
• Max wing loading: 376.7 kg/m² (77.1 lb/sq ft)
• Max power loading: 295.5 kg/kN (2.90 lb/lb st)

PERFORMANCE:

• Max cruising speed at 7,620 m (25,000 ft): 437 knots (810 km/h; 503 mph)
• Econ cruising speed: 400 knots (740 km/h; 460 mph)
• T-O speed: 119 knots (220 km/h; 137 mph) IAS
• Approach speed: 114 knots (210 km/h; 131 mph) IAS
• Max cruising height: 9,600 m (31,500 ft)
• T-O balanced field length: 2,200 m (7,220 ft)
• Landing from 15 m (50 ft): 1,100 m (3,610 ft)
• Range at econ cruising speed, with 3,000 kg (6,615 lb) fuel reserves:
• with max payload: 702 nm (1,300 km; 807 miles)
• with 120 passengers (10,800 kg; 23,810 lb payload): 1,025 nm (1,900 km; 1,180 miles)
• with 104 passengers (9,360 kg; 20,635 lb payload): 1,240 nm (2,300 km; 1,430 miles)
• with max fuel: 2,105 nm (3,900 km; 2,423 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