Ми-26: Советский и российский тяжёлый транспортный вертолёт

Soviet/Russian heavy transport helicopter

The Mil Mi 26 (Миль Ми 26, NATO reporting name: Halo) is a Soviet/Russian heavy transport helicopter. Its product code is Izdeliye 90. Operated by both military and civilian operators, it is the largest helicopter to have gone into serial 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 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 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 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 1977 and the first production aircraft was rolled out on 4 October 1980. The Mi 26's unique main gearbox is relatively light at but can absorb , which was accomplished using a non planetary, split torque design with quill shafts for torque equalization. The Mil Design Bureau designed the VR 26 transmission itself, due to Mil's normal gearbox supplier not being able to design such a gearbox. The gearbox housing is stamped aluminum. as of 2016, the Mi 26 still holds the Fédération Aéronautique Internationale world record for the greatest mass lifted by a helicopter to – on a flight in 1982. In July 2010 a proposed Russian Chinese development of a 33 ton heavy lift helicopter was announced. In early 2019, Russia's state corporation Rostec inked a landmark agreement on developing a 40 ton next generation heavy helicopter. Rostvertol, the Russian helicopter manufacturer, was contracted to refurbish and upgrade the entire fleet of Mi 26s serving in the Russian Air Force, estimated to be around 20 helicopters. The upgraded aircraft is comparable to a new variant, the Mi 26T. Contract completion was planned for 2015. The contract also covered 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 were delivered by 2014. In all, Rostvertol delivered fourteen Mi 26s to domestic and foreign customers in the period 201214 and six helicopters in 2015. Deliveries to the Russian Aerospace Forces were continued in 2016, 2017 and 2019. In 2016, Russia started development of PD 12V a variant of the Aviadvigatel PD 14 turbofan engine to power the Mi 26.

The developers of the Buran space vehicle programme considered using Mi 26 helicopters to "bundle" lift components for the Buran spacecraft, but test flights with a mock up showed this to be risky and impractical.

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.

In October 1999, an Mi 26 was used to transport a block of frozen soil encasing a preserved, 23,000 year old woolly mammoth (Jarkov Mammoth) from the Siberian tundra to a lab in Khatanga, Russia. Due to the weight of the load, the Mi 26 had to be returned to the factory afterward to check for airframe and rotor warping caused by the potential of structural over stressing.

As a result of the magnitude 8.0 earthquake in Sichuan province of China on 12 May 2008, many rivers became blocked by landslides, resulting in the formation of so called quake lakes: large amounts of water pooling up behind the landslide formed dams. These dams eventually broke under the weight of the water, endangering those downstream. At least one Mi 26 belonging to a branch of China's civil aviation service was used to bring heavy earth moving tractors to the quake lakes at Tangjiashan mountain, located in difficult terrain and accessible only by foot or air.

In July 2009, a Moldovan Mi 26 was shot down in Helmand province with the loss of six Ukrainian crew members. The aircraft, belonging to Pecotox Air, was said to be on a humanitarian mission under NATO contract.

On 14 December 2010, an Indian Air Force Mi 26 crashed seconds after taking off from Jammu Airport, injuring all nine passengers. The aircraft fell from an altitude of about 50 feet (15 m). The Indian Institute of Flight Safety released an investigation report that stated improper fastening of the truck inside caused an imbalance of the helicopter and led to the crash. The Mi 26 had been carrying machines from Konkan Railway to Jammu–Baramulla line project.

On 11 December 2012, a Westland Sea King from No. 330 Squadron RNoAF experienced undisclosed technical issues and made an emergency landing on Mount Divgagáisá. The landing caused parts of the landing gear to break. The Sea King was prepared by removing rotor blades and fuel before it was airlifted to Banak Air Station by a Russian Mil Mi 26 on 23December 2012.

During the 2022 Ukrainian Kharkiv counteroffensive, Russian Mi 26s helicopters were involved in transfer of reinforcements on the frontline, namely in the vicinity of towns Izium and Kupiansk.