“Pushing the Envelope” with new X3 Flight Testing
Eurocopter, February 14, 2012 - Eurocopter’s X3 hybrid helicopter demonstrator will soon take to the skies for a third phase of testing, further exploring high-speed rotorcraft flight prior to making a tour in the United States for US Army demonstrations.
The X3 previously made headlines in its 2010-2011 flight testing as Eurocopter validated the hybrid configuration’s capabilities, which uses a Dauphin helicopter airframe equipped with two turboshaft engines that power a five-blade main rotor system, along with propellers installed on short-span fixed wings. This creates an advanced transportation system offering the speed of a turboprop-powered aircraft and the full hover flight capabilities of a helicopter.
“Originally, we were thinking of retiring the X3 to a museum, but it then was decided to take advantage of this amazing testbed in exploring such questions as main rotor behavior at high speeds – which has never been investigated before,” said Jean-Michel Billig, Eurocopter's Executive Vice President of Engineering. “Another question is the management of control laws, which we use to prevent the advancing main rotor blade from becoming supersonic by reducing rotor RPM and transferring lift to the wings at high speed.”
While the next evaluation phase could lead to the setting of new speed records, Billig said the goal is to better explore the physics of high-speed flight – ensuring Eurocopter matures the hybrid helicopter concept before it is applied to a future product.
He noted that during testing performed in 2010-2011, the X3 easily surpassed its original speed target of 220 knots – reaching 230 knots with less than 70 percent of the power that Eurocopter thought would be needed. “In the next phase, we’ll take the power as far as we can,” Billig added. “If we break a speed record, then it is icing on the cake.”
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