Russian Helicopters plans to perform the maiden flight of its new developmental high-speed rotorcraft towards the end of the decade as it eyes the fledgling market for advanced vertical-lift aircraft.

Development of the airframer's Russian Advanced Commercial Helicopter - or RACHEL - was first revealed at Farnborough air show in 2012. The company is now targeting first flight in 2018, says chief executive Dmitry Petrov.

A flying testbed is being built around a Mil Mi-35 to validate systems that Petrov believes will translate into a 10t-class machine capable of carrying 21-24 people at a cruise speed of 195-205kt (360-380km/h). Comparatively, AgustaWestland's 30-passenger AW101 boasts a cruise speed of 150kt.

Critically, says, Petrov, the aircraft must go into large-volume serial production, rather than exist as an expensive niche product.

In addition to the basic passenger transport model with convertible cabin suitable for offshore operations, Russian Helicopters envisions special variants for search and rescue, patrol and medevac missions.

At this point the company is giving away no clues as to the configuration of RACHEL, although its Mil and Kamov design bureaux in 2011 both fielded concepts for a high-speed helicopter. In addition, when it outlined the RACHEL programme in 2012 Russian Helicopters said it had decided to follow a "twin track" development approach.

Kamov's Ka-92 concept echoes Sikorsky's X2, with coaxial main rotors and a single rear-mounted pusher prop. Mil's Mi-X1 takes a different tack, with a single main rotor and pusher prop with steering vane.

The latter design offers an interesting blend of the X2 or Ka-92 with Eurocopter's X3 hybrid concept, which features a single main rotor and twin pusher props mounted laterally on short wings that provide some lift in forward flight.

The speed parameters Petrov outlined at an August briefing at his Moscow offices fall well below the speeds in excess of 240kt achieved by the Eurocopter and Sikorsky demonstration programmes.

But Petrov believes that while technologies such as those being evaluated at Eurocopter or Sikorsky "will eventually be used", he does not see any market breakthrough for at least five to seven years, during which time conventional rotorcraft will dominate.

RACHEL is being designed to replace the long-standing Mi-8/17 family, and sit alongside the heavier Mi-38. Meanwhile, a flying testbed has been evaluating the upgraded avionics, rotors and engines that will go into serial production with the Mi-171A2.

According to Petrov, this aircraft will "bridge the gap" to RACHEL, and should have a market up to 2025. Talks are ongoing with prospective launch customers, he adds.

Source: Flight International