The Soviet and later Russian Mil Mi-24 helicopter has been produced in many variants, as described below.
In 1966, Soviet aircraft designer Mikhail Mil created a mock-up design of a new helicopter (derived from the Mil Mi-8) which was made with the intent of fulfilling both the role of a close air support aircraft as well as being able to transport infantry into combat.
The Mi-24 went from the drawing board to the first test-flights in less than eighteen months, with the first models being delivered to the Soviet Armed Forces for evaluation in 1971.
As a result of the speedy development, the initial Mi-24 variants had a number of problems: lateral roll, weapon sighting issues, and a limited field of view for the pilot.
A later redesign of the Mi-24's front section solved most of these problems.