Paul Duffy/MOSCOW
Antonov expects the first An-74 twinjet featuring a re-configured, conventional engine installation to be flown before the end of this year.
The first example of the new model, dubbed the An-74-300, is in final assembly at the Kharkov Aircraft Production Factory in Ukraine. The aircraft retains the fuselage of the An-74-200, but differs in having the engines mounted in a more traditional underwing pylon arrangement rather than the overwing scheme previously used on all An-72/74s.A stretched version, provisionally termed the An-74-400, is being developed for the regional market.
Antonov says the redesign follows requests from operators that wanted improved efficiency and did not require the field performance benefits that the earlier overwing engined design offered.
Although conceived as a light military freighter able to operate from short, unpaved strips, the An-72/74 has proved popular in recent years with freight carriers operating from paved airports.
The Coanda effect produced by the engines thrusting over the wings generates additional lift and reduces take-off and landing distances, but the configuration has disadvantages, including larger, more complex nacelles, high stress loads on the inner wing and greater fuel consumption.
The new engine position is expected to result in fuel consumption being reduced by over 20%, boosting range by 500-1,000km (270-540nm). The new model is expected to require a 1,900m (6,230ft) take-off run, and 1,700m for landing with a full payload in standard conditions. It will be equipped with the Progress D-36-3A turbofan which powers earlier models, but will feature the thrust reverser from the D-436T1.
The An-74-300 is being promoted as an inexpensive solution to commercial operators' needs for new freighters. The aircraft will be offered as a 10t (22,000lb) payload freighter or a 52-seat passenger aircraft. Quick change, VIP and medevac versions are also planned.
Antonov expects the first aircraft to fly in the second half of this year. The company is conscious that CIS airlines lack funding to acquire new aircraft, but believes there may be interest from South and Central America, Africa, the Middle East and Asia.
Source: Flight International