Mil Mi-24,Mi-25, Mi-35 [Hind] Akbar (original) (raw)

Mil Mi-24 is a twin-engined combat helicopter intended for close support of ground forces, destruction of armored targets and transportation of persons or cargo. The Mi-24 is not a direct counterpart to the American AH-64 Apache, since unlike this and other Western attack helicopters it is also capable of transporting up to eight troops. As a combination gunship and troop transport, the Hind combat helicopter has no direct NATO counterpart.


Design

The combat helicopter is a flying infantry fighting vehicle, which blends features of both transport and attack helicopters. Soviet pilots called the aircraft 'letayushiy tank' or flying tank. Another common nickname is 'Krokodil' (Crocodile) - due to the helicopter's camouflage and fuselage shape. A characteristic feature of the Mi-24 is a load cabin connected with the flight-deck, which is 2.83 m long, 1.46 m wide and 1.2 m high. It is capable of accommodating up to armed 8 troops; they can fire from their small arms fixed in mountings on side windows which can be opened. The cabin is accessible by a vertically opening clamshell door on each side of the fuselage.

The development of the helicopter commenced in mid-1960s based on the dynamics, power units and other components of the Mi-8. Other components of the airframe came from the Mi-14 Haze, a shore-based, navalized version of the Mi-8 'Hip' with a float bottom and ASW equipment. The Hind went from drawing board in 1968 to first test-flights in less than eighteen months. The first prototype, still with TV2-117 engines, flew in September 1969. First models were delivered to the armed forces for evaluation in 1970. The Mi-24A (Hind-B) did have a number of problems - lateral roll, weapon sighting problems, and limited field of view for the pilot. A heavy redesign of the aircraft front section solved most of these problems. Mi-24A (Hind-A) is the first version, in serial production since 1972. The Mil Mi-24 is a large combat helicopter gunship and low-capacity troop transport operated from 1976 by the Soviet Air Force, its successors, and over thirty other nations.

The Mi-24 was the first helicopter to enter service with the Russian Air Force as an assault transport and gunship. Additional missions include direct air support, antitank, armed escort, and air to air combat. The helicopter was used extensively in the Afghanistan War, becoming the "signature" weapon of the conflict. The Russians have deployed significant numbers of HINDs in Europe and have exported the HIND to many third world countries.

Its design is a classic one with a five-bladed main rotor and three-bladed tail rotor. The core of the aircraft was taken from the Mil Mi-8 (NATO reporting name "Hip"), two top mounted turboshaft engines driving a mid-mounted 17.3 m five-blade main rotor and a three blade tail rotor. The engine positions give the aircraft its distinctive double air intake. The five-blade main rotor is mounted on top of fuselage midsection, while short, stubby, weapon-carrying wings are mounted at the fuselsage midsection. It is powered by TV3-117 engines (2 x 1638 kW). The two turboshaft engines are mounted above body midsection with two round air intakes located just above the cockpit and exhaust ports on the sides of engines. The Hind A fuselage consists of a large, oval-shaped body with a glassed-in cockpit, tapering at the rear to the tail boom. The swept-back tapered tail fin features a rotor on the right on some models, with tapered flats on a boom just forward of the fin. The flight control system uses conventional helicopter style flight controls with positive mechanical linkage, hydraulic boost, and a limited authority automatic flight control system (designed to improve helicopter stability and control as well as reduce pilot workload).

External stores are mounted on underwing external stores points. Each wing has three hardpoints for a total of six stations. A representative mix when targeting armor formations would be eight AT-6 ATGMs, 750x 30-mm rounds, and two 57-mm rocket pods. The aircraft can store an additional ammunition basic load in the cargo compartment in lieu of carrying troops. Armored cockpits and titanium rotor head able to withstand 20-mm cannon hits. Every aircraft has an overpressurization system for operation in a NBC environment.

Weapon hardpoints are provided by two short mid-mounted wings (which also provide lift), each offering three stations. The load-out mix is mission dependent; the Hind can be tasked with close air support, anti-tank operations, or aerial combat. The body is heavily armored and the titanium rotor blades can resist impacts from 12.7 mm rounds. The Hind has only three known vulnerable points: the turbine intakes, the tail rotor assembly, and an oil tank inexplicably but conveniently located beneath the red star on the fuselage. The cockpit is overpressurized to protect the crew in NBC conditions. It is equipped with a hydraulically retractable tricycle type landing gear with a twin-wheel nose unit.

The Mi-24/25 is primarily an attack helicopter, but may also be outfitted for other missions. As a transport it can carry up to eight passengers. In the transport/cargo role it can not only carry internal loads but is capable of external sling loads up to 3,000 pounds. In the air ambulance role, the Mi-24/25 can carry four stretchers and one attendant. The Mi-24/25 cockpit areas and cargo/passenger areas are sealed, environmentally controlled, over pressurized with the airflow chemically/biologically filtered. The aircraft may be equipped with additional internal fuel tanks to extend the range/endurance of the Hind.

The helicopter has a wing with a span of 6.536 m, which can relieve the tail rotor by up to 30 per cent in higher speeds. The HIND's wings provide 22% to 28% of its lift in forward flight. In a steep banking turn at slower airspeeds, the low wing can lose lift while it is maintained on the upper wing, resulting in an excessive roll. This is countered by increasing forward airspeed to increase lift on the lower wing. Because of this characteristic, and the aircraft's size and weight, it is not easily maneuverable. Therefore they usually attack in pairs or multiple pairs, and from various directions.

The HIND is never employed individually -- always in sections of two and where possible in flights of six. The HIND has been used for air to air training. The Russians use balloons as air to air targets for the HIND. Unlike fixed wing aircraft the HIND lives in the helicopter flight environment and can maintain firing parameters on other helicopters for much longer periods of time than the fixed wing. Clutter from terrain flight background or flares will usually distract portable ground fired SAM-7 missiles and the STRAGGER cannot track a target moving much faster than a tank. However, a transport helicopter with a HIND on its tail is a "dead duck."

The core of the aircraft was derived from the Mil Mi-8 (NATO reporting name "Hip"), two top-mounted turboshaft engines driving a mid-mounted 17.3 m five-blade main rotor and a three-blade tail rotor. The engine configuration gave the aircraft its distinctive double air intake. Original versions have an angular greenhouse-style cockpit; Model D and later have a characteristic tandem cockpit with a "double bubble" canopy. Other airframe components came from the Mi-14 "Haze". Two mid-mounted stub wings provide weapon hardpoints, each offering three stations, in addition to providing lift. The load-out mix is mission dependent; Mi-24s can be tasked with close air support, anti-tank operations, or aerial combat.

The body is heavily armored and can resist impacts from .50 caliber (12.7 mm) rounds from all angles, including the titanium rotor blades. The cockpit is an even more heavily armored titanium tub and can resist impact from 37mm cannon rounds. The cockpit and crew compartment are overpressurized to protect the crew in NBC conditions.

Considerable attention was given to making the Mi-24 fast. The airframe was streamlined, and fitted with retractable tricycle undercarriage landing gear to reduce drag. The wings provide considerable lift at high speed, up to a quarter of total lift. The main rotor was tilted 2.5° to the right from the fuselage to counteract dissymmetry of lift at high speed and provide a more stable firing platform. The landing gear was also tilted to the left so the rotor would still be level when the aircraft was on the ground, making the rest of the airframe tilt to the left. The tail was also asymmetrical to give a side force at speed, thus unloading the tail rotor.

A modified Mi-24B, named A-10, was used in several speed and time to climb world record attempts. The helicopter had been modified to reduce weight as much as possible, and among the measures used was to remove the stub wings. The speed record over a closed 1000 km course set on August 13 1975 of 332.65 km/h still stands. As does many of the female specific records set by the all female crew of Galina Rastorgoueva and Ludmila Polyanskaia.[5] On 21 September 1978 the A-10 set the absolute speed record for helicopters with 368.4 km/h over a 15/25 km course. The record stood until 1986 when it was broken by the current record holder, a modified Westland Lynx.

As a combination gunship and troop transport, the Mi-24 has no direct NATO counterpart. While some have compared the UH-1 ("Huey") as NATO's direct counterpart to the Mi-24, this is inaccurate. While UH-1s were used in Vietnam to ferry troops, and were used as gunships, they were not able to do both at the same time. Converting a UH-1 into a gunship meant stripping the entire passenger area to accommodate extra fuel and ammunition, making it useless for troop transport. The Mi-24 was designed to do both, and this was greatly exploited by airborne units of the Soviet Army during the 1980-1989 Soviet invasion of Afghanistan. The closest Western equivalent was the Sikorsky S-67 Blackhawk, which used many of the same design principles and was also built as a high-speed, high-agility attack helicopter with limited troop transport capability; it, like the Mi-24, was also designed using many components from an already existing product, the Sikorsky S-61, itself a close approximation to the Mi-8/Mi-14. The S-67, however, was never adopted for service. Another relatively close western equivalent is the US MH-60L Direct Action Penetrator, a special purpose variant of the UH-60 Black Hawk which is capable of mounting a variety of weapons on its stub wings, including AGM-114 Hellfire missiles and Hydra 70 rockets, in addition to being able to carry up to 14 troops. The MH-60L is also similar in size compared to the Mi-24, but is more utility biased, lacks armor and can carry more troops and payload.


Variants

Mi-24 Hind Variants

Its NATO reporting name is Hind and variants are identified with an additional letter. The export versions, Mi-25 and Mi-35, are denoted as Hind D and Hind E respectively. Versions D and above include a characteristic tandem cockpit with a "double bubble" canopy. Nearly all of the older HIND A, B and C variants have been upgraded or modified to the HIND D or E standard.


In IAF

The IAF currently operates two Mi-25/35 Helicopter Squadrons (No.104 Firebirds and No.125 Gladiators) and has a requirement for at least another unit. SIPRI (Stockholm International Peace Research Institute) reports that 15 helicopters of this type were ordered from Kyrgyzstan in 1994 and were delivered by 1995. The designation is uncertain (Mi-25 or Mi-35) and are apparently second-hand/re-furbished helicopters.

The first unit to fly the Mi-25s was No.125 Helicopter Squadron, "The Gladiators", raised in November 1983. This was followed by No.104 Squadron, "Pioneer Rotarians aka Firebirds", in 1990.


Specifications

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