High-speed helicopter and the Mi-38T

RUSSIA

The LL PSV technology demonstrator achieved a maximum speed of 218kts (403km/h) thanks to a combination of new-generation rotor blades, powerful engines and sleek low-drag fuselage.
Russian Helicopters
The Mi-38T’s first forward flight on November 23, 2018 was a long-awaited event in the protracted process of fielding the brand-new 15.6-tonne transport helicopter for service with the Russian military.
Russian Ministry of Defence

ACCORDING TO Russian Helicopters director general Andrey Boginsky, the high-speed helicopter concept by the Mil Moscow Helicopter Plant (Mil MHP) has been selected by the Russian Ministry of Defence as the basis for development of new-generation designs for military use.

The conceptual design ofered by Mil MHP featured a classic layout with main and tail rotors, capable of sustaining 216kts (400km/h) maximum speed. It uses new technologies for facilitating highspeed flight evaluated on the LL PSV technology demonstrator, an extensively modiied Mi-24K Hind attack helicopter, which achieved a maximum speed of 218kts (403km/h) during testing in October 2016.

In turn, Kamov ofered a much more radical design concept with co-axial compound layout, combining the company’s trademark rotor system with additional propulsion housed in the tail and wings for high-speed flight.

Mil MHP’s principal cutting-edge technology for achieving high-speed flight is new-generation composite main rotor blades, combined with more powerful engines and lowdrag sleek fuselage.

According to Kyrill Sypalo, director general of Russia’s Central Aero- and Hydrodynamics Institute, his organisation has worked on a number of new technologies, together with Mil MHP, in a bid to facilitate high-speed flight.

The new-generation composite rotor blades feature a tip shape optimised to reduce as much as possible the stall of the retreating main rotor blade, which causes excessive vibrations that can inflict serious rotor damage.

The LL PSV’s flight test programme, undertaken by Mil MHP in 2016 and 2017, was primarily aimed at evaluating vibration and noise levels in high-speed flight using the all-new main rotor blades. These blades feature a high-lift aerofoil and a new shaped tip described as being broadly similar to the British Experimental Rotor Programme design, with a highly swept tip. The novel blade shape is intended to provide considerably higher lift compared to traditional designs, while also dealing with the transonic efects on the advancing side, and high alpha stall on the retreating side.

Mi-38T flight testing

Flight testing of the military Mi- 38T derivative was a long-awaited event in the process of ielding the brand-new 15.6-tonne helicopter in production and testing for its launch customer, the Russian Ministry of Defence. The Mi-38T made its maiden flight in hover on November 3, 2018 and then, on November 23, made its first slowspeed forward flight. Both events took place at the factory airield of Kazan Helicopters in Kazan.

The first machine will be used for several months to pass its factory testing programme undertaken by Russian Helicopters before its handover to the Russian Ministry of Defence for further testing.

Development and production of the Mi-38T is based on the civilcertiied Mi-38, upgraded with new systems in order to meet the Russian military airworthiness and operational requirements. Russian Helicopters invested its own funds in an efort to meet a Ministry of Defence technical speciication, under a July 2017 contract that covers production of two Mi-38Ts. Both cabs are set to be used for testing and evaluation purposes by the Russian Ministry of Defence.

Formal delivery of the first prototype, serial number 38015, to the Russian Ministry of Defence is slated for early 2019. Upon successful conclusion of the testing and evaluation efort, the Russian Ministry of Defence will place a production order for an undisclosed quantity of Mi-38Ts.

The Russian Air and Space Force (RuASF) has already announced preliminary plans to use the Mi-38T for a wide array of special missions, such as electronic warfare, medevac and flying hospital, and SAR in service with the RuASF Army Aviation branch. A Mi-38T sub-version, optimised for operations in harsh Arctic conditions, capable of routine flight operations in extremely low temperatures and poor visibility, is also included in the Russian Ministry of Defence medium-to-long-term procurement plan.

In accordance with Russian military requirements, all systems, parts and assemblies are manufactured and supplied by Russian companies; Mi-38s built for export and for civil customers will still use foreign-made parts and systems, mainly in the avionics suite and the fuel system.

Powered by two Klimov TV7-117V turboshafts – each rated at 3,550shp in one engine inoperative mode for 30 seconds and 2,800shp for takeof – the Mi-38T features a new Russian-made crash-resistant fuel system, foldable lightweight seats, slump pads for the undercarriage legs and an increased fuel capacity thanks to the use of auxiliary tanks in the cabin. The list of the militaryspeciic features also includes a new communication system with HF and UHF/VHF radios and a life support system for the crew members wearing immersion suits for prolonged cold weather operations over water.