The first version of this helicopter, were twelve V-24 (Hind) prototypes and development aircraft. One such prototype was modified in 1975 as A-10 for successful speed record attempts (having reached 368km/h) with wings removed and faired over and with inertia-type dampers on the main rotor head.
Other early versions were the Mi-24 (Hind-A) armed assault helicopter, which could carry eight combat troops and three crew members. It could also carry four 57-mm rocket pods on four underwing pylons, four 9M17 Falanga (AT-2 Swatter) anti-tank missiles on two underwing rails, free-fall bombs, plus one 12.7-mm machine-gun in the nose. The Mi-24 (Hind-A) was the first production model.
It was followed up by the second production model the Mi-24A (Hind-B). Both the Mi-24 and Mi-24A entered Soviet Air Force service in 1973 or 1974.
The Mi-24U (Hind-C) was a training version without any armament.
The most common variant is the Mi-24D (Hind-D), a purer gunship than the earlier variants, the first to include the electronics for Anti-tank guided missiles 9M17 Falanga (AT-2 Swatter). The Mi-24D has a redesigned forward fuselage, with two separate cockpits for the pilot and gunner. It is armed with a single 12.7-mm four-barrel machine-gun under the nose. It can carry four 57-mm rocket pods, four 9M17 Falanga (AT-2 Swatter) anti-tank missiles, plus bombs and other weapons.
Small numbers of Mi-24Ds were built as Mi-24DU training helicopters.
The Mi-25 is the export version of the Mi-24D.
Later development led to the Mi-24V (Hind-E) which was first seen in the early 1980s. It armed with newer ATGMs, like the (9M114 Kokon, AT-6 Spiral) with tube launchers. Twelve of those missile are mounted on six wing pylons.
The Mi-35 is the export version of the Mi-24V (Hind-E).
The Mi-24P (Hind-F) gunship version, which replaced the 12.7mm machine-gun with a fixed 30-mm cannon.
The Mi-35P is the export version of the Mi-24P (Hind-F).
Other versions of Mi-24 are the Mi-24RKR (Hind-G1) NBC reconnaissance model, which is designed to collect radiation, biological and chemical samples. It was first seen during the 1986 Chernobyl nuclear disaster. Also known as the Mi-24R, Mi-24RR and Mi-24RKh (Rch).
Mi-24K (Hind-G2) : Army reconnaissance, artillery observation helicopter.
Mi-24PS : Civil police or para-military version.
Mi-24E : Environmental research version.
Mi-35U : Unarmed training verion of the Mi-35.
Mi-24M : Night attack version.
Mi-24VP : Mi-24V armed with twin 30-mm cannon in the nose turret.
Mi-24W : Polish designation for the Mi-24V Hind-E.
The newest variant is the 1995 Mi-24VM, with light-weight fibre main and tail rotors to improve all-round performance, updated avionics to improve night-time operation, new communications gear, shorter and lighter wings, and updated weapon systems to include support for the Ataka, Shturm and Igla-V missiles and a 23 mm main gun. Other internal changes have been made to increase the aircraft life-cycle and ease maintenance. The Mi24VM is expected to operate until 2015.
The Russian military has selected the Mi-24PN upgrade to be their primary attack helicopter. The PN version has a TV and a FLIR camera located in a dome on the front of the aircraft. Other modifications include using the rotor blades and wings from the Mi-28 and fixed rather than retractable landing gear. The Russians received 14 Mi-24PNs in 2004 and plan on eventually upgrading all of their Mi-24s.
Since 1978 around 2,000 Hinds have been manufactured, 600 for export. The U.S. Army operates a number of Hinds in Louisiana for adversary training.
Operators
Afghanistan, Algeria, Angola, Armenia, Azerbaijan, Belarus, Bulgaria, Chad, Cyprus, Croatia, Cuba, Czech Republic, East Germany, Equatorial Guinea, Eritrea, Ethiopia, Georgia, Guinea, Hungary, India, Indonesia, Iraq, Kazakhstan, Kyrgizia, Libya, Macedonia, Mexico, Mozambique, Nicaragua, Nigeria, North Korea, Pakistan, Peru, Poland, Russia, Rwanda, Serbia and Montenegro, Sierra Leone, Slovakia, Sri Lanka, Sudan, Syria, Tajikistan, Ukraine, USA, Uzbekistan, Vietnam, Yemen, Zimbabwe.
Source
Wikipedia 
