Mi-26 Halo

The Mil Mi-26 (NATO reporting name: Halo) is a Soviet, later Russian, heavy transport helicopter designed by the Mil design bureau and produced by Rostvertol. Entering Soviet military and commercial service in 1985, it is the largest helicopter ever series-produced, with a 20-tonne payload and a single eight-bladed main rotor.

Development

The programme, designated Izdeliye 90, began in the early 1970s after the abandonment of the Mil Mi-12. The specification required an empty weight of less than half the maximum take-off weight. Design was led by Marat Tishchenko, successor to Mikhail Mil at OKB-329. The aircraft was to replace the Mi-6 and Mi-12 and carry equipment such as 13-tonne amphibious armoured vehicles or mobile ballistic missiles, previously delivered by An-22 or Il-76. The first flight took place on 14 December 1977, the first production example left the factory on 4 October 1980 and development was completed in 1983. In 1982, a Mi-26 set the FAI record for mass lifted to 2,000 metres, at 56,768.8 kg, still standing in 2024. Rostvertol delivered fourteen aircraft between 2012 and 2014, six in 2015, then further examples to the Russian Aerospace Forces in 2016, 2017 and 2019. Development of the PD-12V turboshaft, derived from the PD-14, began in 2016.

Design

The Mi-26 is the first production helicopter fitted with a single eight-bladed main rotor, 32 m in diameter. The tail rotor has a diameter comparable to that of the MD 500's main rotor. Power comes from two ZMKB Progress D-136 turboshafts of 8,500 kW each, coupled to a load-sharing system allowing single-engine flight depending on weight. The VR-26 main gearbox, designed in-house by Mil, weighs 3,639 kg for 14,700 kW absorbed, with a non-planetary split-torque architecture and quill shafts; its casing is of pressed aluminium. Maximum take-off weight reaches 56,000 kg for an empty weight of 28,200 kg. The crew numbers five and the cabin carries 90 troops or 60 stretchers.

Operational History

Thirty Mi-26s took part in the Chernobyl containment operations in 1986, carrying out radiation measurements and dropping insulating materials onto reactor No. 4. In October 1999, one aircraft carried a 23-tonne block containing the Jarkov mammoth. In 2002, civilian Mi-26s operated by Sportsflite recovered two US Army MH-47E and CH-47 helicopters in Afghanistan, the first contract amounting to $300,000. On 19 August 2002, an overloaded Mi-26 was shot down by a surface-to-air missile in Chechnya: 127 dead, the heaviest toll in the history of rotary-wing aviation. A Moldovan Mi-26 of Pecotox Air was shot down in Helmand in July 2009. The Indian Air Force withdrew its last three examples after an accident at Jammu on 14 December 2010. Russian Mi-26s transported reinforcements to Izium and Kupiansk in 2022.

Variants

• Mi-26: Production military transport version, NATO name "Halo-A".
• Mi-26S: Disaster-response version developed for Chernobyl, with a decontaminating-liquid tank and cabin armour.
• Mi-26T: Civil cargo transport version, produced from 1985.
• Mi-26T2: Version fitted with the BREO-26 avionics suite for all-weather, day and night flight, in production since 22 May 2015.
• Mi-26T2V: Russian military version with NPK90-2V avionics, Vitebsk protection system and blast-resistant seats, first flown in August 2018.