Mil Mi-24: The flying tank

During the 2nd World War, the Germans had effectively used a battle plan named Blitzkrieg to capture vast amounts of enemy territory in a very short span. They had done so using fast moving mechanized divisions which ran through Europe within weeks. They also employed this tactic against the Soviet Union during the Operation Barbarossa and the Soviets learnt the advantages of this tactic the hard way. They wanted their armed forces to be capable of doing the same as part of the massive arms buildup. Hence a wide variety of armored vehicles were under development or entering service during the 1960s. The rise of helicopters as a potent troop transport and fire support platform meant that a helicopter which could do both was sought after. This led to the development of the iconic Mi-24 (NATO designation-Hind), the helicopter this article is about.

Mikhail Mil, the head of the design bureau named after him, ie the Mil helicopter design bureau was the first to realize the need for such a helicopter in the early 1960s. It could carry troops while carrying armament like gun pods and rocket pods along side ATGMs on stub wings mounted on the sides of the fuselage. This concept was originally nicknamed the flying IFV and hence it would provide close air support to troops on the ground with the weapons or take out targets enroute to the landing zone that pose a threat to the helicopters. The concept was designated as V-24 and the early mockup was pretty similar to the UH-1. The original V-24 could carry 8 fully armed troops in the troop compartment along with weapons on the stub wings. It was similar to the UH-1 as the Soviets were closely following the Vietnam war where the UH-1 a.k.a. the Huey was the workhorse for the US army. It was being used heavily in the theater for search and rescue, medevac, ammo & supplies transport, striking ground targets, recon etc. The Americans in the mid 1960s would start development of a dedicated attack helicopter based on the experience gained while using the UH-1 in that role. It would enter service as the AH-1 and remain in production for a much longer time than originally thought.

wp (23)Original Mil V-24 concept

Mil would successfully convince the Soviet Ministry of Defense for starting the official development of the flying IFV concept. The Mil and the Kamov bureaus which were leading the Soviet helicopter industry, were asked to develop such a helicopter. Mil offered 2 designs, a 7 tonne helicopter with a single turboshaft and another 10.5 tonne design with 2 turboshafts. Kamov offered a land based variant of its iconic Ka-25 naval helicopter. It would have stub wings and a redesigned front fuselage to suite the new role. The Soviet MoD selected the twin engined Mil design in the late 1960s and thus work began on this design.

The Mil bureau followed the foot steps of Bell and used components and design from the under trial Mi-14 ASW helicopter, a derivative of the widely used Mi-8. It used the TV3-117 turbo shafts of the Mi-14 producing close to 1700shp. The rotor was 5 bladed which lifted a slender fuselage, designed ground up to reduce drag. The landing gear was fully retracted during the flight, further reducing drag. The weapons were mounted on stub wings which also produced lift thus reducing rotor disc loading. The helicopter however suffered from slip and bank during forward flight. To reduce this the power-plant and center fuselage is 2º30′ off the center line to the right. This remedied the problem while allowing proper aiming of the weapons. The center fuselage was occupied by the troop compartment which could carry 8 fully armed troops or 1.5 tonnes of cargo. Over 2 tonnes of cargo could be carried externally on the sling. The stub wings could carry nearly 1 tonne of weapons including bombs and napalm.

Mi_24_HIND_GUNSHIP_russian_russia_military_weapon_helicopter_aircraft__61__1680x900This pic of a late model Hind clearly shows the off-center engines and center fuselage.

The design of the front fuselage was unique. It was nicknamed greenhouse as it sported large bullet proof windows. The pilots sat tandem in the cockpit. The cockpit was extended in the B variant to fit the new generation of avionics before receiving a major re-design to its present shape. After the original Mi-24 entered service with the old cockpit, it was realized that the view out of the cockpit was very poor. The WSO and the pilot blocked certain part of each other’s view thus reducing the over all situational awareness. A major redesign was done and the entire front fuselage was redesigned. The redesign resulted in a stepped cockpit design which we are used to seeing. The WSO sits in front of the pilot and his cockpit is slightly lower than that of the pilot. This design entered service as the Mi-24D. The redesigned cockpit also improved the vision of sensors mounted on it. They were placed below the front fuselage in a teardrop housing. The nose also housed sensors. This forced a change in the nose landing gear, the length of the nose gear was increased thus giving it the iconic nose high attitude on the ground. Like the early Mi-8s, the tail rotor was on the starboard side on the early variants, this was changed to port side on the later variants.

mi-24AOld model Hind with the Greenhouse cockpit

There were several experimental variants of the Hind as well. One had a fenestron tail rotor while another had a tail turret, fitted just behind to troop compartment. Tail gun turret concept originated from the request put up by Soviet pilots which were fighting in Afghanistan. They wanted some protection from the rear as 48% of all the damage sustained from ground fire was in the rear half. The Mi-8 however had a door in the rear clam-shell doors for a machine gun but Mi-24 would get badly shot up as they climbed up after a pass. This plan was dropped as it affected the flight characteristics of the aircraft and the turret used to get filled up with exhaust gases making the conditions unbearable for the gunner. Another dedicated variant, designated A-10 was used to break speed records. Measures were taken to reduce its weight. The stub wings, all the avionics were removed ,the rotor head was changed to reduce weight. It set an absolute speed record of 368kph on 21st September 1978. This record stood for nearly 8 years before being broken by Westland Lynx equipped with the BERP rotors.

Mi-24_fenestron_01Old model Mi-24 with a Fenestron 

Mi-24,35 (6)The tail turret can be seen just below the Soviet star, aft of the wings.

Mi-24 entered service with the Soviet air force in the early 1970s but the Soviets only got an effective tank killer when the Mi-24D entered service. The official role was to provide fire support to the Mi-8s and the troops carried on them during their mission. They were also used to strike ground targets. The Hind was sluggish with a payload in the troop compartment and hence it was rarely used as a transport. It mostly flew as a dedicated attack helicopter. Another interesting role given to the helicopter was destruction of aerial targets flying at medium and low altitudes. In a dogfight the Mi-24 was very good in the vertical but bad at horizontal maneuvering. The Hind’s primary enemy before the arrival of the AH-64 was the AH-1 and there have been several dogfights between the two during the Iran-Iraq war. Both sides for sure have killed helicopters of the other side using machine guns and missiles but the results have been widely disputed. A rare incident occurred on 27th of October 1982 when a Hind shot down an Iranian F-4 using anti tank missiles.

Mi-24,35 (6)A Hind with 2 R-60 IR guided AAMs (Credits-On the pic)

In service experience made it pretty clear that this helicopter was a flying tank and could absorb large amounts of damage. The helicopter had armor in the cargo compartment and the cockpit. Important systems had back ups while the entire chopper could operate in NBC environment with ease. Helicopters of that era lacked retractable landing gear and pilots at times forgot to retract them or even worse deploy them while landing. The helicopter suffered several belly landings and yet it was ready for flight after repairs. On many occasions the chopper returned with badly damaged blades and shot up engines. The engines kept running after ingesting birds, foliage, branches and a lot of other stuff not meant to be in there. A case worth mentioning happened in Schchit-79 (Shield-79) a WarPac exercise during which a Hind flew under artillery fire by mistake and got its engine shot up by shrapnel. The pilots could hear that the engines were producing abnormal sound but they didnt fail and bought the helicopter back safely. The cockpit windows were bulletproof and not a single case of them being penetrated by AA fire is known.

The helicopter was baptized by fire in the African conflicts but its major test was the Afghan conflict. The hot and high conditions reduced payload and maneuverability. It would carry just 2 ATGMs and 2 rocket pods. The pilots developed several new maneuvers, some of which were banned as they fell outside the operational envelope. The designers were shocked to see these maneuvers and exclaimed that they thought they knew everything about the helicopter they had designed. As mentioned above, they were rarely used for transport instead they usually escorted Mi-8 and Mi-6 to the landing sites and back. They also provided top cover to friendly convoys and assaults by friendly troops. During the Afghan campaign, Stinger along with captured Strelas became major threat to Soviet helicopters. The Soviets modified their helicopters with flare launchers and IR jammers to reduce loses still several Hinds were shot down during the conflict. The last Hind was shot down while covering the Soviet pullout from the theater.

Mi-24 (5)A Hind fitted with exhaust suppressors over a Soviet convoy.

The weapons suite of the Hind family varies a lot with variants. Some variants had a 12.7mm Gatling gun in the nose while later model Hinds had a dual barrel Gsh-30K gun on the starboard side of the cockpit. The Gsh-30 is well known for its devastating fire power and hence it was preferred over the Gatling even though the Hind only carried around 750 rounds for the cannon as opposed to nearly twice that for the Gatling. The wing mounted hardpoints could be used for external tanks, S-5 rocket pods, 500kg bombs etc. The wing tips also had a couple of hardpoints on each side which were used to deploy ATGMs and AAMs only. The gun pods carried included the GUV-8700. This massive gun pod had 2 configurations, one had 3 Gatlings one 12.7mm and two 7.62mm with 750 rounds for the bigger gun and 1500 for the 2 smaller ones. In this configuration, the pod had massive rate of fire, over 12000 rounds per minute. The other configuration had a single 30mm grenade launcher fed by a magazine consisting of 300 rounds.

Mi-24 (5)Both the configurations of GUV-8700 pod are seen in this picture.

The future of this attack helicopter is not so promising. It still remains in production in Russia with several countries buying new built Hinds. The Russians themselves have been buying them, using them as trainers for the new generation of attack helicopters entering service. These new helicopters, like the Mi-28 lacked a dedicated trainer variant and hence Hinds are used to fill up the role. With the arrival of Mi-28U, they might stop buying new Hinds. Iraq has ordered both the Hinds and Mi-28 and has been actively using them during the recent conflicts. They have suffered loses as well. The new variant presently in production lacks retractable landing gear while the length of the wings has been reduced. The avionics however have been thoroughly upgraded along with the weapons suite. This variant has been designated as the Mi-35M by the Russians.  It can carry the traditional rockets along with modern ATGMs like Vikhr and Ataka. The nations which operate these have no plans to retire them and are upgrading them with new avionics to improve their combat proficiency. The Hind isn’t going to give up its job soon.

Mi-24,35 (2)Mi-35M of the Russian air force.

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