The Mil Mi-26 (Russian: Миль Ми-26, NATO reporting name: Halo) is a Soviet/Russian heavy transport helicopter. In service with civilian and military operators, it is the largest and most powerful helicopter ever to have gone into production.
Following the incomplete development of the heavier Mil V-12 (also known as Mi-12) in the early 1970s, work began on a new heavy-lift helicopter, designated Izdeliye 90 ("Project 90") and later allocated designation The Mil Mi-26. The new design was required to have an empty weight less than half its maximum takeoff weight. The helicopter was designed by Marat Tishchenko, protégé of Mikhail Mil, founder of the OKB-329 design bureau.
The Mi-26 was designed as a heavy-lift helicopter for military and civil use, and was to replace earlier Mi-6 and Mi-12 heavy lift helicopters, with twice the cabin space and payload of the Mi-6, then the world's largest and fastest production helicopter. The primary purpose was to move military equipment like 13 metric ton (29,000 lb) amphibious armored personnel carriers, and mobile ballistic missiles, to remote locations after delivery by military transport planes such as the Antonov An-22 or Ilyushin Il-76.
The first Mi-26 flew on 14 December 1977 and the first production aircraft was rolled out on 4 October 1980. Development was completed in 1983, and the Mi-26 was in Soviet military and commercial service by 1985.
The Mi-26, which was seen in public for the first time at the 1981 Paris Air Show, is the result of a specification issued at the beginning of the seventies for a transport helicopter whose empty weight, without fuel, was not to exceed half the maximum take-off weight. It first flew on 14 December 1977 and has two very powerful turbine engines driving a big eight-blade rotor, and a large cargo hold 3.20m wide, 3.15m high and 15m deep with two winches on overhead rails, each capable of lifting 2.5 tonnes. Access to the hold is through a hydraulically-actuated rear loading ramp. The maximum payload is 5000kg or 70-100 passengers. The helicopter has a crew of four, with room for an additional handler, and has a full range of navigational electronics and an automatic hover system.