Russian Gunship Helicopters by Yefim Gordon

Author:Yefim Gordon
Language: eng
Format: epub
Tags: Bisac Code 1: JWMV3; HIS027140; HISTORY / Military / Aviation
ISBN: 9781473831391
Publisher: Pen and Sword
Published: 2013-04-10T16:00:00+00:00

As originally envisaged, the Mi-28 was to have been a compound helicopter with side-by-side rotors. Note the pusher propeller and the ventrally mounted cannon.

As reference points the Mil’ OKB took the Mi-24 and the best foreign helicopter in the class – the Hughes (later McDonnell Douglas Helicopters, now Boeing) AH-64 Apache which they aspired to surpass on all major counts. The designers strove to achieve high weight efficiency coupled with the requisite strength, reliability and resistance to battle damage. Numerous structural layout versions were considered, including an unorthodox fuselage configuration featuring a so-called ‘central core’ where all vital parts and systems were placed inside a central longitudinal stressed structure flanked by equipment bays and assemblies of secondary importance. However, calculations showed it would be difficult to achieve the necessary strength and vibration characteristics; besides, the equipment would be too vulnerable. The attractive configuration had to be relinquished in favour of a conventional semi-monocoque fuselage.

To ensure survivability, systems components were duplicated and placed far apart or located in such a way that vital units were protected by less important ones; the same purpose was served by armour-plating arrangements, structural materials and dimensions of structural members carefully chosen in such a way as to exclude catastrophic structural failure in case of battle damage for long enough to allow the chopper to return home. The all-round bulletproof glazing could withstand hits of 12.7-mm armour-piercing bullets and 20-mm high-explosive/fragmentation cannon shells; the main rotor blades were designed to survive hits of 30-mm rounds.

The cockpit layout became a key element of the design. Side-by-side seating was rejected outright because this layout did not afford the necessary field of view for either crewmember and complicated bailing out in an emergency. The engineers opted for a stepped-tandem arrangement which had proved its worth on the Mi-24, with the pilot sitting behind and above the WSO; the individual cockpits had car-type doors.

By the end of 1977 the OKB had completed the advanced development project (ADP) and reached an understanding with the subcontractors responsible for the equipment and armament. The subsequent eighteen months were used for co-ordinating with the customer all aspects of the specification concerning the helicopter and its avionics and armament fit, and in 1979 the OKB started detail design of the helicopter and the testing of the first experimental specimens of assemblies and systems.

In its final form the Mi-28 (izdeliye 280) had a narrow fuselage mated to a low-set slender tailboom terminating in a swept tail rotor pylon with a portside stabiliser at the top. The low location of the tailboom precluded the possibility of the main rotor blades striking it during a violent manoeuvre. Like its predecessor, the Mi-28 had anhedral stub wings with four pylons for carrying external stores; however, the wings had much shorter span (4.88 m; 16 ft 0 in) and lacked vertical endplates. The stub wings could be jettisoned in an emergency. The helicopter had a number of built-in survivability features. For example, the powerplant was basically the same as on

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