Compiled by: Gp Capt Kumar Kirinde [retd], SLAF
The Mil V-12 (NATO reporting name: Homer), is the largest helicopter ever built. Construction of the first prototype was completed in 1968. A first flight on 27 June 1967 ended prematurely due to oscillations caused by control problems; one set of main wheels contacted the ground hard bursting a tyre and bending a wheel hub.
The first prototype made its first flight on 10 July 1968 from the Mil factory pad in Panki to the Mil OKB test flight facility in Lyubertsy. In February 1969, the first prototype lifted a record 31,030 kg (68,410 lb) payload to 2,951 m (9,682 ft). On 6 August 1969, the V-12 lifted 44,205 kg (97,455 lb) to a height of 2,255 m (7,398 ft), also a world record.
The second prototype was also assembled at the Mil experimental production facility in Panki but sat in the workshop for a full year awaiting engines, flying for the first time in March 1973 from Panki to the flight test facilities in Lyubertsy.
The prototype V-12s outperformed their design specifications, setting numerous world records which still stand today, and brought its designers numerous awards such as the prestigious Sikorsky Prize awarded by the American Helicopter Society for outstanding achievements in helicopter technology. The V-12 design was patented in the United States, United Kingdom, and other countries.
Despite all of these achievements the Soviet Air Force refused to accept the helicopter for state acceptance trials for many reasons, the main one being that the V-12’s most important intended mission no longer existed, i.e. the rapid deployment of heavy strategic ballistic missiles.
In May–June 1971, the first prototype V-12 made a series of flights over Europe culminating in an appearance at the 29th Paris Air Show.
All development on the V-12 was stopped in 1974. The first prototype remained at the Mil Moscow Helicopter Plant near Moscow. The second prototype was donated to Central Air Force Museum 50 km (31 mi) east of Moscow for public display.
The Mil Mi-26 (NATO reporting name: Halo) is a Soviet/Russian heavy transport helicopter. Operated by both military and civilian operators, it is the largest and most powerful helicopter to have gone into serial (mass) production.
Following the incomplete development of the heavier Mil Mi-12 (prototypes known as Mil V-12) in the early 1970s, work began on a new heavy-lift helicopter, designated as the “Project 90” and later allocated designation Mi-26. The helicopter was designed by Marat Tishchenko, protégé of Mikhail Mil, founder of the OKB-329 design bureau.
The Mi-26 was designed to replace earlier Mi-6 and Mi-12 heavy lift helicopters and act as a heavy-lift helicopter for military and civil use, having twice the cabin space and payload of the Mi-6, then the world’s largest and fastest production helicopter. The primary purpose of the Mi-26 was to transport military equipment such as 13-tonne (29,000 lb) amphibious armored personnel carriers and mobile ballistic missiles to remote locations after delivery by military transport aircraft such as the Antonov An-22 or Ilyushin Il-76.
The first Mi-26 flew on 14 December 197 and the first production aircraft was rolled out on 4 October 1980. Development was completed in 1983 and by 1985, the Mi-26 was in Soviet military and commercial service.
The Mi-26 was the first factory-equipped helicopter with a single, eight-blade main lift rotor. It is the second largest and heaviest helicopter ever constructed, after the experimental Mil V-12. The tail rotor has about the same diameter and thrust as the four-bladed main rotor fitted to the MD Helicopters MD 500.
As of 2016, the Mi-26 still holds the Fédération Aéronautique Internationale world record for the greatest mass lifted by a helicopter to 2,000 metres (6,562 ft) – 56,768.8 kilograms (125,000 lb) on a flight in 1982.
Courtesy: Sources: https://en.wikipedia.org/wiki/Mil_V-12, https://en.wikipedia.org/wiki/Mil_Mi-26 and Google Images