Airbus' Racer Breaks Speed Target, Moves Toward Eco Mode Tests

LE BOURGET—Airbus Helicopters has achieved its speed target with its Racer compound rotorcraft, successfully flying the experimental aircraft at 240 kt. (276 mph) in April.

The aircraft reached the speed with power margin to spare, test pilots say, and after only 25 flying hours—one-eighth of the flying hours that have been “justified” for the flight-test program—which points to the maturity of the aircraft’s design.

Racer—short for Rapid and Cost-Effective Rotorcraft—broke its initial speed target of 220 kt. after just seven flights last June. While the speed is just 15 kt. short of the record set 15 years earlier by Racer’s predecessor, the Eurocopter X³, test pilots note that Racer achieved the speed while being two metric tons heavier than the X³ and having roughly the same engine power. Airbus has not yet disclosed the maximum takeoff weight of the Racer, but company officials have described it as being in the 7-8 metric ton class.

With Racer, Airbus aims to prove its compound technology can be used to increase helicopter speed, range and endurance without significant increases in the cost of operation.

Now, the aircraft will be prepared for the next phase of testing with the installation of an eco-mode that will allow one of the two Safran Aneto 1X engines to be shut down for more economic cruise flight. Speaking on the fourth day of the Paris Air Show here, Racer Chief Engineer Brice Makinadjian said testing to support the installation of the eco mode already had begun ahead of work starting on the aircraft in September.

Testing has included recording distortion of the engine, confirming that the aircraft can meet the target cruise speed with a single engine by flying at power settings lower than 50% on both engines, as well as flying on a single engine. Like modern automobile start/stop systems, which turn off engines when stopped in traffic, the eco mode will shut down one engine when in cruise. When required, for landing or hover, a 100-kW battery system will quickly spool the shutdown engine up to full power within 5-7 sec. Batteries for the eco mode system will be fitted into the cabin of the aircraft.

Airbus has no plans to try to break the 255-kt. cruise speed record broken by the X³, despite the record being tantalizingly close, although the aircraft did achieve 262 kt. in a dive.

“What we intend to demonstrate is the mission capability … not being the speediest helicopter between two gas stations,” said Hervé Jammayrac, the Racer test pilot who has been flying displays at the air show. “Speed is not the question. For this concept, the optimum speed is 220 kt., otherwise you will only gain very marginally in terms of range and payload,” Jammayrac added.

Beyond the eco mode testing, the company also intends to perform several as-yet-undefined demonstrations that will look at “speed, maneuverability, range performance and the ease of flying the aircraft.”

Racer is one of two high-speed rotorcraft demonstrators funded by the European Union’s Clean Sky 2 initiative, the other being Leonardo’s Next-Generation Civil Tiltrotor Technology Demonstrator. The Leonardo aircraft is expected to take to the air before year's end.