Eurocopter test pilot Hervé Jammayrac and experimental flight test engineer Dominique Fournier were at the Paris Air Show to discuss their record-breaking flight in Eurocopter’s X3 technology demonstrator aircraft. The X3 flew at 255 knots (293 mph) in level flight and 263 knots in a dive, topping the previous Sikorsky X2 record of 250 knots level/260 in decent set in September 2010.
Fournier said that the record attempt was made because the aircraft still had power in reserve when it recorded 232 knots earlier. There were 17 flights between the first flight in September 2010 and the May 12, 2011 232-knot run, with the crew continually looking at different flight regimes and parameters every time they got to fly the X3. “We tried to recommend where to innovate, and where not to innovate to keep the cost low,” said Fournier. “We had in mind where the technology we were testing might have a serial application,” he added. “The maximum high speed turn we achieved was 2G at 210 knots.”
Photos by Andrew Drwiega
Fournier described the transition between aircraft mode and helicopter mode as seamless. As there is little pitch in the rotor, “you point the nose where you want to land, reduce the speed with the trim, and at 40 knots start pulling the collective up.” He added that to autorotate (although they actually only did the steady phase of autorotation in the air, with the flare and the touch-down portion conducted in the sim), the pitch of the props are set to zero thrust and then just flair and land like a normal helicopter.
When demonstrating the aircraft in the United States, where they flew 55 hours, they said that pilots were amazed that the aircraft could be so steady in a dive without increasing speed or vibration.
Fournier said that an experienced helicopter pilot would require around four hours in the simulator and one flight hour to convert to the X3. Unfortunately none will get the opportunity as there are only around 10 hours left until the program has run its course, with nothing further planned after that.