Mil Mi-26

The Mil Mi-26, known by its NATO reporting name “Halo,” stands as a monumental achievement in the field of rotorcraft engineering, representing the pinnacle of Soviet and Russian heavy transport helicopter design. With its product code designated as Izdeliye 90, the Mi-26 has been a vital asset for both military and civilian operators around the globe. It holds the distinction of being the largest helicopter ever to be put into serial production, a testament to its engineering marvel and operational capability.

The origins of the Mi-26 trace back to the early 1970s following the incomplete development of the Mil Mi-12, also known as the Mil V-12 prototypes. The need for a new heavy-lift helicopter was paramount, leading to the initiation of a project known as Izdeliye 90, which later took on the designation Mi-26. The design and development of this helicopter were spearheaded by Marat Tishchenko, a protégé of the legendary Mikhail Mil, who founded the OKB-329 design bureau. The primary design criterion was ambitious: to create a helicopter with an empty weight less than half of its maximum takeoff weight, a challenging feat that underscored the innovative spirit of Soviet aerospace engineering.

The Mi-26 was envisioned as a successor to the earlier Mi-6 and Mi-12 heavy-lift helicopters. It was designed to serve both military and civilian roles, offering twice the cabin space and payload capacity as the Mi-6, which was then the world’s largest and fastest production helicopter. The helicopter’s primary mission was to transport military equipment, including 13-tonne amphibious armored personnel carriers and mobile ballistic missiles, to remote locations. These operations were often conducted in conjunction with military transport aircraft like the Antonov An-22 or the Ilyushin Il-76, which would deliver the payloads to forward bases before the Mi-26 took over for the final leg of the journey.

The Mi-26’s maiden flight took place on December 14, 1977, marking the beginning of a new era in heavy-lift helicopter operations. The first production model was rolled out on October 4, 1980, with development reaching completion by 1983. By 1985, the Mi-26 had entered service with Soviet military and commercial operators, quickly proving its worth in various demanding environments.

One of the Mi-26’s most notable features is its single, eight-blade main lift rotor, which was a pioneering design at the time. This rotor system allows the helicopter to maintain flight even in the event of an engine failure, thanks to an innovative engine load-sharing system. While its empty weight is only slightly greater than that of the Mi-6, the Mi-26 boasts an impressive payload capacity of up to 20 tonnes, making it the second largest and heaviest helicopter ever constructed, surpassed only by the experimental Mil V-12.

The helicopter’s tail rotor is noteworthy as well, possessing a diameter and thrust comparable to the four-bladed main rotor of the MD Helicopters MD 500. The Mi-26’s main gearbox, a critical component of its design, is relatively lightweight at 3,639 kg yet capable of absorbing an astonishing 14,700 kilowatts of power. This was achieved using a non-planetary, split-torque design with quill shafts for torque equalization. The gearbox housing is crafted from stamped aluminum, showcasing the advanced metallurgy and manufacturing techniques employed by the Mil Design Bureau.

As of 2024, the Mi-26 still holds a world record recognized by the Fédération Aéronautique Internationale for the greatest mass lifted by a helicopter to an altitude of 2,000 meters: an astounding 56,768.8 kilograms, achieved during a flight in 1982. This record underscores the helicopter’s unparalleled lifting capabilities and its importance in both military and civilian operations.

In recent years, there have been initiatives to further develop and enhance the Mi-26’s capabilities. In July 2010, a proposal for a joint Russian-Chinese development of a 33-ton heavy-lift helicopter was announced, highlighting the continued interest in expanding heavy-lift rotorcraft technology. By early 2019, Russia’s state corporation Rostec signed an agreement to develop a next-generation 40-ton heavy helicopter, indicating ongoing advancements in this field.

Rostvertol, the renowned Russian helicopter manufacturer, has played a crucial role in the modernization and production of the Mi-26. The company was contracted to refurbish and upgrade the entire fleet of Mi-26s serving in the Russian Air Force, a fleet estimated to comprise around 20 helicopters. This extensive upgrade program was expected to be completed by 2015 and included the production of 22 new Mi-26T helicopters. By January 2012, eight newly built helicopters had already been delivered to operational units, with a total of 17 new-production helicopters delivered by 2014. Between 2012 and 2014, Rostvertol delivered fourteen Mi-26s to both domestic and international customers, followed by six additional helicopters in 2015. Deliveries to the Russian Aerospace Forces continued in subsequent years, reinforcing the Mi-26’s role as a critical asset in Russia’s aerial fleet.

In 2016, development began on the PD-12V, a variant of the Aviadvigatel PD-14 turbofan engine, intended to power future iterations of the Mi-26, further enhancing its performance and reliability.

Over the years, the Mi-26 has seen the development of numerous variants, each tailored to specific operational requirements. These include: