The second Mi-171A2 prototype has begun flight tests at the Mil Moscow Helicopter Plant, Russian Helicopters reported. The unit of the state corporation Rostec said certification testing also is underway. The latest development of the medium, multi-role Mi-8/Mi-17 series incorporates improved technical features, including twin, 2,700-hp (1,985-kW) VK-2500PS-03 engines equipped with full-authority digital engine controllers, a Safir auxiliary power unit designed to enable the engine to start at altitudes of up to 19,700 ft (6,000 m) and composite main- and tail-rotor blades. The Mi-171A2 also includes the KBO-17 avionics suite, with five multi-function glass displays. Increased automation on the helicopter has reduced the required crew size from three people to two.