NATO reporting name: Coaler

TYPE: Twin-turbofan light STOL transport.

PROGRAMME: First of two prototype An-72s, built at Kiev, flew 31 August 1977; after eight pre-series aircraft, manufacture transferred to Kharkov; An-74 polar transport announced February 1984; over 150 An-72/74 aircraft have been built.

VARIANTS: An-72A ('Coaler-C'): Light STOL transport for military and civil use; extended wings, lengthened fuselage and other changes compared with An-72 ('Coaler-A') prototypes; crew of two or three.
An-72AT ('Coaler-C'): Cargo version of An-72A, able to carry international standard containers.
An-72S ('Coaler-C'): Three-compartment executive transport; toilets, wardrobe and galley for hot and cold meals at front; centre compartment has small table, three-place sofa, wardrobe and baggage space starboard, table, two pivoting armchairs and intercom port, with six armchairs optional in place of sofa and wardrobe; 12 pairs of armchairs in rear compartment. Provision for adapting to carry light vehicle, freight, 38 persons in seats along sidewalls and in centre row, or eight stretcher patients.
An-74 ('Coaler-B'): For all-weather operation in Arctic/Antarctic, to assist in setting up scientific stations on ice floes, airdrop supplies to motorised expeditions and observe changes in icefields; flight crew of five; wing, tail unit and engine air intake de-icing; advanced navigation aids, including inertial navigation system; provision for wheel/ski landing gear; much increased fuel capacity; airframe identical with An-72A except for two blister windows at rear of flight deck and front of cabin on port side, and larger nose radome.
An-74A ('Coaler-B'): As An-72A, but with avionics and larger radome of An-74.
An-74AT ('Coaler-B'): Cargo version of An-74A.
An-74S ('Coaler-B'): Executive transport version of An-74A.
An-74-300: Described separately.
'Madcap': AEW&C version.

DESIGN FEATURES: Primary role as STOL replacement for turboprop An-26, with emphasis on freight carrying; ejection of exhaust efflux over upper wing surface and down over large multi-slotted flaps gives considerable increase in lift; special ramp/door as An-26; low-pressure tyres and multi-wheel landing gear for operation from unprepared strips, ice or snow; high-set engines avoid foreign object ingestion; wing leading-edge sweepback 17°; anhedral approx 10° on outer wings; normal T-O flap setting 25-30°, max deflection 60°; sweptback fin and rudder.

FLYING CONTROLS: Power actuated ailerons, with two tabs in port aileron, one starboard; double-hinged rudder, with tab in lower portion of two-section aft panel; during normal flight only lower rear rudder segment is used; both rear segments used in low-speed flight; forward segment is actuated automatically to offset thrust asymmetry; horn balanced and mechanically actuated, aerodynamically balanced elevators, each with two tabs; hydraulically actuated full-span wing leading-edge flaps outboard of nacelles; trailing-edge flaps double-slotted in exhaust efflux, triple-slotted between nacelles and outer wings; four-section spoilers forward of triple-slotted flaps; two outer sections on each side raised before landing, remainder opened automatically on touchdown by sensors actuated by weight on main landing gear; inverted leading-edge slat on tailplane linked to wing flaps.

STRUCTURE: All-metal; multi-spar wings mounted above fuselage; wing skin, spoilers and flaps of titanium aft of engine nacelles; circular semi-monocoque fuselage, with rear ramp/door; tapered fairing forward of T-tail fin/tailplane junction, blending into ogival rear fairing.

LANDING GEAR: Hydraulically retractable tricycle type, made primarily of titanium. Twin wheels on rearward retracting steerable nose unit. Each main unit comprises two trailing-arm legs in tandem, each with a single wheel, retracting inward through 90° so that wheels lie horizontally in bottom of large fairings, outside fuselage pressure cell. Oleo-pneumatic shock absorber in each unit. Low pressure tyres, size 720 x 310 mm on nosewheels, 1,050 x 400 mm on mainwheels. Hydraulic disc brakes. Telescopic strut is hinged downward, from rear of each side fairing, to support fuselage during direct loading of hold with ramp door under fuselage.

POWER PLANT: Initial versions have two Zaporozhye/Lotarev D-36 high bypass ratio turbofans, each rated at 63.74 kN (14.330 lb st). These have been superseded by two Zaporozhye/Lotarev D-436 lurbofans, each rated at 73.6 kN (16,550 lb st). Integral fuel tanks between spars of outer wings. Thrust reversers standard.

ACCOMMODATION: Pilot and co-pilot navigator side by side on flight deck of An-72, plus a flight engineer, with provision for a fourth person: pilot, co-pilot, navigator, radio operator and flight engineer in An-74. Heated windows. Two windscreen wipers. Flight deck and cabin pressurised and air-conditioned. Main cabin designed primarily for freight, including four UAK-2.5 containers or four PAV-2.5 pallets each weighing 2,500 kg (5,511 lb); but An-72 has folding seats for 68 passengers along side walls and on removable central seats. It can carry 57 parachutists, and has provision for 24 stretcher patients. 12 seated casualties and an attendant in ambulance configuration. An-74 is able to carry eight mission staff in combi role, in two rows of seats, with tables, and with two bunks installed, one on each side of cabin aft of seats. Bulged observation windows on port side for navigator and hydrologist. Provision for wardrobe and galley. Movable bulkhead between passenger and freight compartments, with provision for up to 1,500 kg (3,307 lb) of freight in rear compartment. Large downward hinged and forward sliding rear ramp door for loading trucks and tracked vehicles, and for direct loading of hold from trucks, as described under An-26 entry. It is openable in flight, enabling freight loads of up to 7,500 kg (16,535 lb), with a maximum of 2,500 kg (5,511 lb) per individual item, to be airdropped by parachute extraction system. Removable mobile winch, capacity 2,500 kg (5,511 lb), assists loading of containers up to 1.90 x 2.44 x 1.46 m (6 ft 3 in x 8 ft x 4 ft 9½ in) in size, pallets 1.90 x 2.42 x 1.46 m (6 ft 3 in x 7 ft 11 in x 4 ft 9½ in) in size, and other bulky items. Cargo straps and nets are stowed in lockers on each side of hold when not in use. Provision for huilding roller conveyors into floor. Main crew and passenger door at front of cabin on port side. Small emergency exit and servicing door at rear of cabin on starboard side.

SYSTEMS: Air-conditioning system provides comfortable environment to altitude of 10,000 m (32,800 ft), with independent temperature control in flight deck and main cabin areas. It can he used to refrigerate main cabin when perishable goods are carried. Hydraulic system for actuating landing gear, flaps and ramp. Electrical system powers auxiliary systems, flight deck equipment, lighting and mobile hoist. Thermal de-icing system for leading-edges ol wings and tail unit (including tailplane slat), engine air intakes and cockpit windows. Provision for APU in starboard landing gear fairing. This can be used to heat the cabin; and, under cold ambient conditions, servicing personnel can gain access to major electric, hydraulic and air-conditioning components without stepping outside.

AVIONICS: HF com, VHF com/nav, ADF. Large radome over navigation weather radar in nose. Doppler-based automatic navigation system, linked to onboard computer, is preprogrammed before take-off on push-button panel to right of large map display. Failure warning panels above windscreen display red lights for critical failures, yellow lights for non-critical failures, to minimise time spent on monitoring instruments and equipment. 'Odd Rods' IFF standard. An-74 has enhanced avionics, including INS.