As mentioned before, the Antonov An-72 / 74 is primarily designed for STOL operations and as a direct replacement for the Antonov An-26. General characteristics of the aircraft include a high-wing config, T-tail, with an upswept rear fuselage for freight access. The ejection of exhaust efflux over the upper wing surface and down over large multislotted flaps gives a considerable increase in lift as well as avoiding foreign object ingestion. Furthermore, low-pressure tyres and a multiwheel landing gear makes operation from unprepared airstrips possible.
Flight Controls The An-72 / 74 is fitted with a conventional assisted flight control system. It includes power-actuated ailerons, with two tabs in the port aileron, one double-hinged rudder, with a tab in the lower portion of the two-section aft panel. During normal, high-speed flight, only the lower rear rudder segment is used while both are being operated in low-speed flight. The forward segment is actuated automatically in order to offset any thrust asymmetry. The elevators are horn-balanced and mechanically actuated. High lift devices include hydraulically actuated full-span wing leading-edge flaps outboard of each nacelle, trailing-edge double-slotted flaps in the exhaust efflux, and triple-slotted trailing-edge flaps between each nacelle and outer wing portion. Four-section spoilers are located forward of the triple-slotted flaps; two outer sections on each side are raised before landing while the remainder are opened automatically on touchdown by sensors actuated by weight on the main landing gear.
Structure
All metal, multispar wings are mounted above the fuselage. The fuselage is of the semi-moncoque type, with a rear loading door, a tapered fairing forward of the T-tail fin, blended into an ogival rear fairing.
Powerplant
The aircraft is powered by two ZMKB Progress/Ivchenko D-36 high-bypass ratio turbofan engines, each capable of producing 14,330 pounds of thrust. Both engines are fitted with thrust reversers.
Accomodation
The aircraft is flown by a crew of three, consisting of a pilot and co-pilot side by side on the flight deck together with a flight navigator. Cockpit windows are heated by the aircraft internal electrical system and are equipped with windscreen wipers. The An-72 has folding seat along the sidewalls of the cabin and removable central seats for a total of 68 passengers. It can carry 57 parachutists, and has provision for 24 stretcher patients, 12 seated casualties and an attendant in ambulance configuration. The Antonov An-74 can carry eight mission staff in combi role, together with tables and bunks. Another visual characteristic of the aircraft are the bulged windows on the port side of the aircraft for both the navigator and hydrologist.
Systems
The An-72 / 74 is fitted with an air conditioning system with independant temperature control in the flight deck and main cabin areas; used mainly to refrigerate perishable goods when carried in the main cabin. Hydraulic system powers the landing gear, flaps and rear cargo ramp while the electrical system powers all auxiliary systems, flight deck equipment, lighting and mobile hoist. A de-icing system is installed for the leading-edges of the wings, tail unit (including the tailplane slat), engine air intakes and cockpit windows. Provision is made for a TA-12 APU in the starboard landing gear fairing which can be used to heat the cabin in cold ambient temperatures. Furthermore, servicing personnel can gain access to major electric, hydraulic and air conditioning components without stepping outside.
Avionics
The aircraft is equipped with navigation and weather radar located in the nose section. It has a Doppler-based automatic navigation system, linked to the onboard computer. The Antonov An-74 has enhanced avionics compared to the An-72 and includes GPS, GPWS and TCAS 2000. Twin Head-Up-Displays which were under development by 2003. |