The Mil Mi-26 (Russian: Миль Ми-26, NATO reporting name: Halo), given the product code izdeliye 90, is a Soviet/Russian heavy transport helicopter. In service with civilian and military operators, it is the largest and most powerful helicopter to have gone into series production.
Design and development
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 Izdeliye 90("Project 90") and later allocated designation Mi-26. The new design was required to have an empty weight less than half its maximum takeoff weight. The helicopter was designed byMarat 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.
Aeroflot Mi-26 at the 1984 Farnborough Air Show
The Mi-26 was the first factory-equipped helicopter with a single, eight-blade main lift rotor. It is capable of flight in the event of power loss by one engine (depending on aircraft mission weight) thanks to an engine load sharing system. While it is only slightly heavier than the Mi-6, the Mi-26 can lift up to 20 metric tons (44,000 lb). It is the second largest and heaviest helicopter ever constructed, after the experimental V-12. The tail rotor has about the same rotor diameter and thrust of the four-bladed MD 500 main rotor.
The Mi-26's unique main gearbox is relatively light at 3,639 kg (8,022.62 lb) but can absorb 19,725 shp, which was accomplished using a non-planetary, split-torque design with quill shafts for torque equalization. Because Mil's normal gearbox supplier said that such a gearbox could not be designed, the Mil Design Bureau designed the VR-26 transmission itself. The gearbox housing is stamped aluminum. A split-torque design is also used for the 12,500 lb (5,670 kg) gearbox on the three-engine CH-53K.
As of 2013, the Mi-26 still holds the FAI record of greatest mass lifted to 2,000 metres - it lifted 56,768.8 kg in 1982.
In July 2010 a proposed Russian-Chinese development of a 33-ton heavy-lift helicopter was announced.
The Russian helicopter manufacturer, Rostvertol, is in the process of refurbishing and upgrading the entire fleet of Mi-26s serving in the Russian Air Force. The fleet is estimated to total around 20 helicopters. The upgraded aircraft will be comparable to a new variant, the Mi-26T. Contract completion is planned for 2015. The contract also covers the production of 22 new Mi-26T helicopters. Eight new-built helicopters were delivered to operational units by January 2012. Under the 2010 contract, 17 new-production helicopters have been delivered through 2014.
A Mi-26 in a military parade over Caracas, Venezuela
The developers of the Buran space vehicle programme considered using a couple of Mi-26 helicopters to "bundle" lift components for the Buran spacecraft, but test flights with a mock-up showed how risky and impractical that was.
The Mi-26S was a disaster response version hastily developed during the containment efforts of the Chernobyl nuclear accident in 1986. Thirty Mi-26 were used for radiation measurements and precision drops of insulating material to cover the damaged No. 4 reactor. It was also equipped with a deactivating liquid tank and underbelly spraying apparatus. The Mi-26S was operated in immediate proximity to the nuclear reactor, with a filter system and protective screens mounted in the cabin to protect the crew during delivery of construction materials to the most highly contaminated areas.
World Team skydiving
For three weeks in September 1996, the Russian military loaned four fully crewed Mil Mi-26 helicopters and granted the use of its Anapa airbase to the World Team for its skydiving free fall formation world record attempt. The World Team was made up of top-tier skydivers from over 40 countries and led by Hollywood aerial stunt performer B. J. Worth. With the goal of setting a new 300-way free fall formation record and using the high altitude and high capacity performance of the Mi-26, the World Team quickly flew 300 participants, plus aerial judges, photographers, and cinematographers up to 6,700 metres (22,000 ft), then simultaneously dropped them in a tight formation. The Mi-26 helicopter crews and equipment performed flawlessly in their first experience with close formation flying, and flew away with an assist in the new 297-way world record set on 27 September 1996, just three shy of the objective.
Siberian Woolly Mammoth recovery
In October 1999, a Mi-26 was used to transport a 25-ton block of ice encasing a well-preserved, 23,000-year-old Woolly Mammoth from the Siberian tundra to a lab in Khatanga, Taymyr, where scientists hoped to study the find and perhaps attempt to clone it. The weight was reportedly so great that the Mi-26 had to be returned to the factory immediately thereafter to check for airframe and rotor warping caused by the potential of structural over-stressing from such a heavy load.
Afghanistan Chinook recovery
In the spring of 2002, a civilian Mi-26 was leased to recover two U.S. Army MH-47E Chinook helicopters from a mountain in Afghanistan. The Chinooks, operated by the 160th Special Operations Aviation Regiment, had been employed in Operation Anaconda, an effort to drive al Qaeda and Taliban fighters out of the Shahi-Kot Valley and surrounding mountains. They ended up stranded on the slopes above Sirkhankel at altitudes of 2,600 metres (8,500 ft) and 3,100 metres (10,200 ft). While the second was too badly damaged to recover, the first was determined to be repairable and estimated to weigh 12,000 kilograms (26,000 lb) with fuel, rotors, and non-essential equipment removed. That weight exceeded the maximum payload of 9,100 kilograms (20,100 lb) at an altitude of 2,600 metres (8,500 ft) of the U.S. military's Sikorsky CH-53E.
The Mi-26 was located through Skylink Aviation in Toronto, which had connections with a Russian company called Sportsflite that operated three civilian Mi-26 versions called "Heavycopters". One of the aircraft, doing construction and firefighting work in neighboring Tajikistan, was leased for $300,000; it lifted the Chinook with a hook and flew it to Kabul, then later to Bagram Air Base, Afghanistan to ship to Fort Campbell, Kentucky, U.S. for repairs. Six months later, a second U.S. Army CH-47 that had made a hard landing 100 miles (160 km) north of Bagram at an altitude of 1,200 metres (3,900 ft) was recovered by another Sportsflite-operated Mi-26 Heavycopter.
On 19 August 2002, Chechen separatists hit an overloaded Mi-26 with a surface-to-air missile, causing it to crash-land in a minefield and killing 127 of the people on board.