The first prototype of Russian Helicopters' Mi-171A2 medium twin made its maiden flight today, one month after hover testing started. This followed ground runs of the prototype and flight-testing of the rotor system and engine on a Mi-171LL “flying laboratory.” The ground tests suggested a 20-percent increase in cruise and maximum speeds, 1,700 pounds more main rotor thrust and reduced vibration, Russian Helicopters said. The Mi-171A2's maximum speed of 150 knots was subsequently confirmed during the first flight.

The A2's main rotor has composite blades and improved aerodynamics, according to the Russian helicopter manufacturer. It is powered by “more powerful and more economic” Klimov VK2500PS-03 turboshafts, it said, while the avionics suite is based on an open-architecture Radioelectronic Technologies KBO-17.

A higher level of automation allows for a reduction from three to two required crewmembers. The second prototype is being assembled with new main and tail rotors, smoother vertical and horizontal fins, an external sling, air conditioning, energy-absorbing seats for 24 passengers and anti-dust equipment. Russian Helicopters expects the Mi-171A2 to be certified by Russian authorities later next year.