The Mil Mi-28 (NATO reporting name "Havoc") is a Russian all-weather, day-night, military tandem, two-seat anti-armor attack helicopter. It is a dedicated attack helicopter with no intended secondary transport capability, better optimized than the Mil Mi-24 gunship for the role. It carries a single gun in an undernose barbette, plus external loads carried on pylons beneath stub wings.
First flown in November 1982, and designed to fulfil the same role as the American AH-64 Apache which it generally resembles, the agile Mi-28 'Havoc' military helicopter was scheduled to enter full service with the CIS forces in 1992, but lost out to the Kamov Ka-50. The three prototypes had a conventional three-bladed tail rotor but this has since been replaced by a 'delta 3' x-configured rotor comprising two independent two-bladed propellers mounted on the same shaft.
The gunner, seated in a heavily-armoured front cockpit ahead of the pilot, controls a 30mm cannon normally used on ground vehicles. This is mounted under the nose, which contains a low light level TV and FLIR night control systems. Stub wings, each fitted with two hardpoints, can carry AT-6 'Spiral' radio-guided ATMs, UV-20 pods, or fuel tanks. Infra-red suppressors and decoy dispensers are also fitted to the 'Havoc', which is designed to offer high survivability in battle.
Development
Origins
In 1972, following completion of the Mil Mi-24, development began on a unique attack helicopter with transport capability. The new design had a reduced transport capability (3 troops instead of 8) and omitted the cabin, to provide better overall performance and higher top speed. Improved performance was important for its intended role fighting against tanks and enemy helicopters and covering helicopter landing operations. Initially, many different designs were considered, including an unconventional project with two main rotors, placed with engines on tips of wings (in perpendicular layout); and in one similarity with the late 1960s-era American Lockheed AH-56 Cheyenne attack helicopter design, with an additional pusher propeller on the tail. In 1977, a preliminary design was chosen, in a classic single-rotor layout. It lost its similarity to the Mi-24, and even the canopies were smaller, with flat surfaces.
Design work on the Mi-28 began under Marat Tishchenko in 1980.In 1981, a design and a mock-up were accepted. The prototype (no. 012) was first flown on 10 November 1982.The second prototype (no. 022) was completed in 1983. Each prototype different: first and second (no. 022) had upward-pointing exhaust diffusers and fixed undernose fairing for electro-optic equipment; first also had conventional three-blade tail rotor; second replaced this with the definitive "Delta-H" configuration. In 1984, the Mi-28 completed the first stage of state trials, but in October 1984 the Soviet Air Force chose the more advanced Kamov Ka-50 as the new anti-tank helicopter. The Mi-28 development was continued, but given lower priority. In December 1987 Mi-28 production in Rosvertol in Rostov on Don was approved. The first Mi-28A (no.032) introduced the definitive downward-pointing exhaust suppressors and flew in January 1988; second Mi-28A prototype (no.042) demonstrated at Moscow in 1992 and represented the intended production configuration. It had the definitive moving E-O sensor turret undernose, downward-pointing exhaust diffusers and wingtip electronics/chaff dispenser pods; small-scale pre-series production planned, but not initiated, by Rostvertol, Rostov-on-Don, which stated in mid-2001 that it was ready to begin series production.
An early production Mi-24 was fitted with an air data boom as an early test for the Mi-28's technologies. Later, a few Mi-24Ds were fitted up with the Mi-28's radome mount for testing the sighting-flight-navigational complex's abilities, and others had redesigned fuselages that closely resemble the future Mi-28, but with rounded cockpits.
Design Features
Conventional gunship configuration, with two crew in stepped cockpits; original three-blade tail rotor superseded by low noise 'scissors' or "Delta-H" type comprising two independent two-blade rotors set as narrow X (35°/145°) on same shaft with self-lubricating bearings; resulting flapping freedom relieves flight loads; agility enhanced by doubling hinge offset of main rotor blades compared with Mi-24; survivability emphasised; crew compartments protected by titanium and ceramic armour and armoured glass transparencies; single hit will not knock out both engines; new composites main rotor can withstand hit from round of up to 30mm calibre; vital units and parts are redundant, widely separated and shielded by the less vital; multiple self-sealing fuel tanks in centre-fuselage enclosed in composites second skin, outside metal fuselage skin; no explosion, fire or fuel leakage results if tanks hit by bullet or shell fragment; energy absorbing seats and landing gear protect crew in crash landing at descent rate of 12m/s; crew doors are rearward-hinged, to open quickly and remain open in emergency; parachutes are mandatory for Russian Federation and Associated States (CIS) military helicopter aircrew; if Mi-28 crew had to parachute, emergency system would jettison doors, blast away stub-wings, and inflate bladder beneath each door sill; as crew jumped, they would bounce off bladders and clear main landing gear; no provision for rotor separation; port-side door, aft of wing, provides access to avionics compartment large enough to permit combat rescue of two or three persons on ground, although it lacks windows, heating and ventilation.
Hand crank, inserted into end of each stub-wing, enables stores of up to 500kg to be winched on to pylons without hoists or ground equipment; current 30mm gun is identical with that of RFAS army ground vehicles and uses same ammunition; jamming averted by attaching twin ammunition boxes to sides of gun mounting, so that they turn, elevate and depress with gun; main rotor shaft has 5° forward tilt, providing tail rotor clearance; transmission capable of running without oil for 20 to 30 minutes; main rotor rpm 242; with main rotor blades and wings removed, helicopter is air-transportable in An-22 or Il-76 freighter.
Structure
Five-blade main rotor; blades have very cambered high-lift section and sweptback tip leading edge; full-span upswept tab on trailing-edge of each blade; structure comprises numerically controlled, spirally wound glass fibre D-spar, blade pockets of Kevlar-like material with Nomex-like honeycomb core, and titanium erosion snip on leading-edge; each blade has single elastomeric root bearing, mechanical droop stop and hydraulic drag damper; four-blade GFRP tail rotor with elastomeric bearings for flapping; rotor brake lever on starboard side of cockpit; strong and simple machined titanium main rotor head with elastomeric bearings, requiring no lubrication; power output shafts from engines drive main gearbox from each side; tail rotor gearbox, at base of tail pylon, driven by aluminium alloy shaft inside composites duct on top of tailboom; sweptback mid-mounted wings have light alloy primary box structure, leading- and trailing-edges of composites; no wing movable surfaces; provision for countermeasures pod on each wingtip, housing chaff/flare dispensers and sensors, probably RWR; light alloy semi-monocoque fuselage, with titanium armour around cockpits and vulnerable areas; composites access door aft of wing on port side; swept fin has light alloy primary box structure, composites leading- and trailing-edges; cooling air intake at base of fin leading-edge, exhaust at top of trailing-edge; two-position composites horizontal stabiliser.
Armament
The Mi-28 is equipped with a chin-mounted 30 mm Shipunov 2A42 autocannon. The cannon is select fire, and has a dual-feed, which allows for a cyclic rate of fire between 200 rounds per minute to 550 rounds per minute. Its effective range varies from 1,500 meters for ground vehicles to 2,500 meters for air targets. Rounds from High Explosive Incendiary (HEI) to Armour-Piercing Discarding Sabot (APDS) can be used. Stated penetration for the 3UBR8 is 25 mm of RHA at 1,500 meters.
One common Mi-28 armament are a pair of 8 Ataka missile racks along with 2 B-13L rocket pods, each able to carry 5 S-13 rockets. Other rocket options include two B-8 rocket pods, each able to carry up to 20 S-8 rockets.
There are four variants of the Ataka missile for different tasks. The 9M120 Tandem High Explosive Anti-Tank (HEAT) warhead variant is used against tanks fitted with Explosive Reactive Armor (ERA), its penetrative ability is stated at 800 mm Rolled Homogeneous Armour (RHA).The 9M120F Thermobaric variant is used against infantry, buildings, bunkers, and caves. The 9M120O expanding rod warhead variant is used against other helicopters. All the variants have a range of 6 km. The 9M120M improved version has a longer range (8 km) and better penetration (900 mm of RHA).All of the variants use SACLOS missile guidance.
The S-8 and S-13 rockets used by the Mi-28 are usually unguided. In the most common configuration, one can expect 40 S-8 rockets or 10 S-13 rockets. Both rockets have their variants, from HEAT warheads to a Thermobaric warhead. The S-8 has a shorter range and smaller warhead than the S-13, but compensates with numbers. Currently, the Russian Air Force are upgrading their S-8 and S-13 rockets to laser guidedmissiles with the proposed Ugroza ("Menace") system. Rockets upgraded under Ugroza would receive designations S-8Kor and S-13Kor, respectively.
System
Cockpits air conditioned and pressurised by engine bleed air. Duplicated hydraulic systems, pressure 152 bar. 208V AC electrical system supplied by two generators on accessory section of main gearbox, ensuring continued supply during autorotation. Low-airspeed system standard, giving speed and drift via main rotor blade-tip pitot tubes at -50 to +70km/h in forward flight, and ±70km/h in sideways flight. Main and tail rotor blades electrically de-iced. Ivchenko AI-9V APU in rear of main pylon structure supplies compressed air for engine starting and to drive small turbine for preflight ground checks.
Avionics
Comms: UHF/VHF nav/com; small IFF fairing each side of nose and tail.
Instrumentation: Conventional IFR instrumentation, with autostabilisation, autohover, and hover/heading hold lock in attack mode; pilot has HUD and centrally mounted CRT for basic TV; aircraft designed for use with night vision goggles.
Mission: Radio for missile guidance in nose radome. Daylight optical weapons sight and laser range-finder in gyrostabilised and double-glazed nose turret above gun, with which it rotates through ±110°; wiper on outer glass protects inner optically flat panel.
Self-defence: Two fixed IR sensors on initial basic production Mi-28; IR suppressors, radar and laser warning receivers standard; optional countermeasures pod on each wingtip, housing chaff/flare dispensers and sensors, probably RWR. Mi-28N has integrated Vitebsk DASS with Pastel RWR, Mak IR warning system, Platan jammer and UV-26 flare dispensers.
Power plant
Two Klimov TV3-117VMA turboshafts, each 1,636kW, in pod above each wingroot; three jetpipes inside downward-deflected composites nozzle fairing on each side of third prototype shown in Paris 1989; upward deflecting type also tested. Deflectors for dust and foreign objects forward of air intakes, which are de-iced by engine bleed air. Internal fuel capacity 1,720 litres. Provision for four external fuel tanks on underwing pylons.
Landing Gear
Non- retractable, tailwheel type; single wheel on each unit; mainwheel tyres size 720x320, pressure 5.40 bar; castoring tailwheel with tyre size 480x200.
Fire control and surveillance
The pilot uses a helmet-mounted target designator, which allocates the target to the navigator's surveillance and fire control system. The navigator / weapons officer is then able to deploy guided weapons or guns against the target. The targeting system follows the direction of the pilot's eyes.
The integrated surveillance and fire control system has two optical channels providing wide and narrow fields of view, a narrow-field-of-view optical television channel, and laser rangefinder. The system can move within 110° in azimuth and from +13° to -40° in elevation.
Hydraulically powered mechanical type; horizontal stabiliser linked to collective; controls for pilot only.
Current versions
Mi-28: First two prototypes with 1,434kW TV3-117BM engines and VR-28 gearbox.
Mi-28A (Type 280): Basic version, as described in detail, Third and fourth aircraft built.
Mi-28N: (Nochnoy: Night): Unofficial names: Night Hunter and Night Pirate. Added night/all-weather operating capability. Russian Army funding announced January 1994; demonstrator (014) modified from first Mi-28 prototype (012); first hover 14 November 1995; formal roll-out 16 August 1996; first flight 30 April 1997. Mast-mounted 360° scan millimetre wave Kinzhal V or Arbalet radar (pod soon enlarged in vertical plane); FLIR ball beneath missile-guidance nose radome and above new shuttered turret for optical/laser sensors, including Zenit low-light-level TV. EFIS cockpit. Armament of production version to include 9M114 Shturm (AT-6 'Spiral') or 9M120 Vikhr/Ataka (AT-12 'Swinger') ASMs and Igla (SA-16 'Gimlet') AAMs and R-73 AAMs. New composites rotor with sweptback blade tips added subsequently. Mi-28N introduced uprated VR-29 transmission and IKBO integrated flight/weapon aiming system, with automatic terrain-following and automatic target search, detection, identification and (in formations of Mi-28Ns) allocation; Ramenskoye Breo-28N mission control system.
Second prototype Mi-28N due for completion in first quarter of 2003 and will undertake bulk of state testing, which expected to occupy minimum of three and maximum of five years, after which it is intended to begin quantity production for the Russian armed forces and export customers.
Total of five trials Mi-28Ns to be built by Rostvertol; TV3-117VMA engines initially, but 1,839kW Klimov VK-2500s to be installed later. Second helicopter funded jointly by Rostvertol and Southwest Sberbank.
Versions projected for naval amphibious assault support and air-to-air missions.
Mi-28NEh: (Nochnoy, Ehksport: Night, Export): Version of above offered to South Korea in 2000. Evaluated by Swedish Army in 2001 against Boeing AH-64 Apache and Eurocopter Tiger.
Technical data for Mi-28
Crew: 2, engine: 2 x Klimov TV3-117VM turboshaft, rated at 1620kW, main rotor diameter: 17.2m, length with rotors turning: 21.6m, height: 3.82m, take-off weight: 11200kg, empty weight: 7000kg, fuel: 1337kg, max speed: 300km/h, cruising speed: 270km/h, rate of climb: 13.6m/s, service ceiling: 5800m, hovering ceiling: 3500m, range with max fuel: 460km
