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Eurocopter X3 hybrid helicopter combines rotor system and two wing-mounted propellers; exceeds speed challenge at 232 knots

Eurocopter’s X3 hybrid helicopter demonstrator has achieved a speed milestone on 12 May during stable, level flight, delivering a true airspeed of 232 knots (267 mph, 430 km/h) for several minutes; its original speed target was 220 kts. This occurred during only the third mission after a scheduled upgrade that integrated the X3’s definitive gearboxes, enabling it to operate at full power.

The X3. Click to enlarge.

The X3 utilizes a Eurocopter Dauphin helicopter airframe equipped with two turboshaft engines that power a five-blade main rotor system and two propellers which are installed on short-span fixed wings. This hybrid configuration creates an advanced transportation system offering the speed of a turboprop-powered aircraft and the full hover flight capabilities of a helicopter.

Eurocopter began X3 flight testing last September in a program that combines the excellent vertical takeoff and landing capabilities of a helicopter with aircraft-type fast cruise speeds of more than 220 kts. After the X3 achieved the initial true airspeed goal of 180 kts (333 km/h) in November at a reduced level of engine power, the X3 underwent its planned gearbox upgrade and safety inspection.

Since returning to flight last week, the X3 demonstrated its performance at full engine power, including climb and descent rates, as well as maneuverability, while also confirming the hybrid propulsion system’s capabilities for acceleration and deceleration.

In the test program to date, the X3’s basic handling characteristics and stability have been validated throughout the aircraft’s flight envelope without the need of a stability augmentation system, which has been confirmed in testing performed with the autopilot disengaged and engaged. In addition, the hybrid aircraft has low vibration levels without the use of passive or active anti-vibration systems, providing flight characteristics comparable to those of the best traditional design helicopters currently in service.

The company envisions a wide range of utilizations for this concept, including long-distance search and rescue (SAR) missions, coast guard duties, border patrol missions, passenger transport, offshore operations and inter-city shuttle services. It also could be well-tailored for military missions in special forces operations, troop transport, combat SAR and medical evacuation – benefitting from the hybrid aircraft’s combination of higher cruise speeds with excellent vertical takeoff/landing performance.

Flight testing of the X3 is being performed from the DGA Flight Test Center in Istres, France. The flight test program will continue throughout 2011 to explore the hybrid helicopter’s full flight envelope and evaluate all of the possibilities offered by this new technology.

Future helicopters incorporating the X3 configuration will offer our customers about 50 percent more cruise speed and range at very affordable costs, therefore defining the future of high productivity rotary-wing aircraft.

—Lutz Bertling, Eurocopter’s President & CEO


Maximum speed: 260 knots[18] (299 mph, 481 km/h)
Cruise speed: 250 knots (287.5 mph, 460 km/h)


ai_ the S-69 co-axial rotor with turbojets looks to even more fun:

322 mph, 518 km/h (184 mph, 296 km/h)


Counter rotating eliminates a tail rotor. The jet engine thrust is a good idea as well. I would prefer one of these over an Osprey any day.


Why not drive a generator with the axial turbine prop and drive the wing mounted props with electric motors fed from the generator?


I like the hybrid idea, instead of auto rotation you can actually land where you want. Now that you have electricity and storage, run the forward thrust props from that and while you are at it make them counter rotating as well.


Yes Reel, I know about the S-69's higher maximum speed, but I didn't mention it because the stated goal in this article was "cruising speed."


It seems like lift is a major factor for troop movements. With dual rotor blades, I would think that there would be plenty of lift and speed.


MD had a small one with thrust out the tail and no rotor. I do not know if that would work on a larger design, but I thought it was good.

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