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Sikorsky’s X2 demonstrator outpaces conventional helicopters at 208 mph


June 1, 2010

X2 Technology demonstrator reaches 181 knots in flight #12 at West Palm Beach facility

X2 Technology demonstrator reaches 181 knots in flight #12 at West Palm Beach facility

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Sikorsky Aircraft’s goal of producing the fastest helicopter ever built has taken another step towards becoming a reality. Its coaxial X2 Technology demonstrator has achieved a speed of 181 knots (208 mph) in a test flight – faster than the 160-170 knot speeds generally possible with conventional helicopters and edging closer to the eventual aim of delivering 250 knot (288 mph) cruising speeds.

As we’ve reported previously, the X2 demonstrator combines an integrated suite of technologies intended to advance the state-of-the-art, counter-rotating coaxial rotor helicopter. These include fly-by-wire flight controls, counter-rotating rigid rotor blades, hub drag reduction, active vibration control and an integrated auxiliary propulsion system.

After the latest test flight Jim Kaglis, Program Manager, Sikorsky Advanced Programs for Sikorsky, said, “the X2 Technology demonstrator today exceeded average helicopter speeds of a conventional helicopter, generally 160-170 knots.”

“The demonstrator is proving out the technologies very well, from the active vibration control system to the fly-by-wire controls. There are no show stoppers here so far, and now the program turns a corner, as this completes phase three of four. We are flying forward to the 250-knot cruise speed," Kaglis added.

Naturally speed isn’t the only feature Sikorsky is aiming for with its new helicopter technology. Attributes such as excellent low-speed handling, efficient hovering, and a seamless and simple transition to high speed are also desirable, and are all things that were successfully demonstrated on previous test flights.

In case you were wondering, the record of the world's fastest helicopter has been held for over 20 years by the British built Westland Lynx ZB-500, which reached 249.1 miles per hour (400.8 km/h) at a European air show in 1986.

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag. All articles by Darren Quick

Nothing irritates me more than trying to sleep at night, only to be jolted awake by a low flying OUTRAGEOUSLY LOUD police helicopter.

As usual, the important things are left out of your articles. I have petitioned the city council of Los Angeles and the police department about their helicopters. Usually they only come out and fly around looking for the nearest donut shop. After waking everyone up in the neighborhood they insist on hovering over, or flying round and round with this deafening sound, they finally leave, with nothing happening.

Now if your article said that these helicopters were SILENT, wafting through the air with the greatest of ease, well then I would be greatly impressed.

Perhaps you could do a follow up story about this important ingredient in developing helicopters, It is my best guess with the double windmills on top of this sleek new model will be making TWICE the noise of the regular helicopter.

I wish Sikorsky would develop a silent helicopter for the police and the military. Don\'t you think that would be a great idea????

There is much too much noise in this world.


Not only fast but because it has no wasted tail rotor power it\'s more eff, carries a larger load/hp and far less likely to get damaged/crash from the tail rotor, a major cause of helicopter crashes.


Hmmm, very good, but a British Westland Lynx using a rigid rotor head and conventional tail rotor reached a whisker over 249mph (in excess of 400knots) way back in August 1986. What have Sikorsky been doing all this time? ;)

Mike Hallett

@jerryd: I imagine that pusher prop at the back end would consume a fair bit of power, especially as it is presumably used to augment main rotor thrust in straight and level flight at speed. It would also be almost as vulnerable as a conventional tail rotor when hovering in restricted spaces, woodland clearings, cliff faces etc. I can only assume there is some directional control over the prop to achieve lateral manoeuvring in the hover because, as far as I know, there is no resultant torque to \"manipulate\" with contra-rotating main rotors.

Interesting project. I wonder if they\'ll fit it with winglets to off-load the main rotors at high speed. They may as well, \'cos they are going to need somewhere to hang the mini-guns, missiles, bombs and rockets that they undoubtedly have in mind for it... :)

Mike Hallett

What ever happened to the speed records made by the Lockheed model L-286(H-51) rigid rotor demonstrator and AH-56 helicopters, they were flying more than 250 MPH in the 1960s.

Ret. Engineer


What Jerry is talking about to is efficiency. The power consumed by the tail rotor does not add to the speed or lift. It is wasted countering the torque produced by the main rotor.

While you may damage the pusher prop, it will no longer be a major emergency due to loss of yaw control.

Controlling the yaw on a co-axial is done by differentiating the lift produced by each rotor; the collective of one goes up while the other goes down and the combined lift stays the same.

Winglets would compromise hovering performance. One of the aims of the project is to gain higher cruising speeds while maintaining hovering performance.



When I hear a heli fly overhead at night, a flush of calm comes over me and I feel at peace in the world. Luckily for you, though, those many short blades should make it quieter.


How about having the rotor blades auto rotate like an auto-gyro. Also there could be winglets fitted that hang down for take off, and raise horizontally for forward flight.


The limiting factor for helicopter speed is the blade tip velocity reaching mach 1 as it is being driven forward. So the only way for a helicopter to go faster is to have a smaller diameter rotor, and because the lift is so much less that\'s why they need two or more rotors.



Not true. The main limiting factor is retreating blade stall. That doesn\'t matter so much when you have another rotor running the opposite direction since you now have lift from both sides.


Autogyros are slow. The main rotors create huge drag -- they convert forward airspeed into lift.


Autogyros aren\'t that slow, check out Carter Copter http://www.cartercopters.com/


I suspect that the contra-rotating main rotors in the Sikorsky X2 are essentially autorotating when the aircraft is at top speed, with most of the power going into the six-bladed pusher propeller at the tail. This helps avoid the problem of retreating blade stall at high forward speed.

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I think that the Carter Copter has been ignored long enough. For too long the military aviation community has been concerned with getting jobs in the local Congressional district and protecting their archaic doctrine of warfare.

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Lockheed AH-56 Cheyenne minus tail rotor plus a second main rotor.

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