Friend of mine who works there sent me this. I am not a helo guy, but this is pretty cool. They apparently have developed some pretty good ways of dealing with the aeroelastic issues surrounding advancing and retreating airfoils. I bet these things would make good light-attack ships too.

WEST PALM BEACH, Florida - Sikorsky Aircraft Corp.’s X2 Technology demonstrator today successfully achieved a speed of 250 knots true air speed in level flight at the Sikorsky Development Flight Center, accomplishing the program’s ultimate speed milestone. Sikorsky is a subsidiary of United Technologies Corp. (NYSE:UTX). The speed, reached during a 1.1-hour flight, is an unofficial speed record for a helicopter. The demonstrator also reached 260 knots in a very shallow dive during the flight. “The aerospace industry today has a new horizon,” said Sikorsky President Jeffrey P. Pino. “The X2 Technology demonstrator continues to prove its potential as a game-changer, and Sikorsky Aircraft is proud to be advancing this innovative technology and to continue our company’s pioneering legacy.” “Our primary key performance parameter has been met,” said Jim Kagdis, Program Manager for Sikorsky Advanced Programs. “The 250-knot milestone was established as the goal of the demonstrator from its inception. It’s exciting to imagine how our customers will use this capability.” Kevin Bredenbeck, Sikorsky’s Director of Flight Operations and Chief Pilot for the company and for its X2 Technology program, manned the milestone flight. Bredenbeck said the demonstrator has been performing well, meeting expectations of performance predictions and progressing with every test flight. “I’m proud of what the X2 Technology team has accomplished,” Bredenbeck said. “This was truly a collaborative effort that demanded a tremendous sacrifice from the full team. This dedication enabled the demonstrator to hit this historically high mark.”

 

252 mph in 1968



now 203 mph and climbing....

YouTube - Piasecki X-49A Speedhawk flight tests



it's about time.

 

Sikorsky would like this design to replace the V-22. The V-22 can cruise at over 300Kts which gives it an advantage in the cargo-delivered-to-objective metric but if an X-2 design could be built for a lot less money than a V-22 it might be a bargain.

But the marines will still prefer the "cool factor" of the V-22 I suspect.

 

The Commander of the 160th came out to speak to my unit and he kept talking about the X2 and how future variant would one day replace the MH-6 Little Bird (MD 530) because of it´s speed. One of the cool features that he mentioned was that it could go from level cruise to hover in nose-level attitude by fully reversing the pitch of the prop and bring the thing to a stop. That made me think, would there be another control in the cockpit just for the pitch of the prop?

One big advantage over the CV-22 that the X-2 has is the lack of transition period between vertical and horizontal flight. It will be cool to see if the technology goes beyond just a tech demonstrator.

 

That's what I was thinking. You'd (I think) still need a collective and to be increasing pitch during the decel. Normal humans run out of appendages. Maybe the 160th guys are issues a 3rd arm. Seriously though, the only thing that comes to mind is a twist like the 58's throttle.

 

According to this youtube video, the cyclic would also twist and control the yaw, and pedals would control forward speed like in a car. Sounds a little odd to me, I like your idea of twisting the collective to control the rear prop.
YouTube - Sikorsky X2 LTH Mock up

According to FlightGlobal, once at high speed, the computer would slow down the speed of the main rotors and control the pitch of the rotorblades to keep the blades at the correct efficiency.
Sikorsky X2 breaks helicopter speed barrier
Lots of FBW tech.

 

Definitely high tech and complicated. Normal helos are speed-limited to about 160Kt because the advancing rotor blade tip goes supersonic. The X2 has to unload and slow the rotors as forward speed picks up. The winglets (if equipped) carry the lift and aft prop provides forward thrust...both of these vectors are provided by the rotor disc in a normal helo.

I think an early version was flown manually using mechanical linkages (by two pilots) but the workload would be too high for normal ops, to say nothing of combat.

 

Eurocopter just flew their version, it looks just as goofy, has two prop's on mini-wings. It's the X3 I think they called it.

 

I have not been in aerospace academia for several years but when I was I recall a ton of research going on to solve problems with helicopter airfoils. Rotating wings have a bunch of unique issues to deal with involving several disciplines at the same time- material science, aerodynamics, aeroelastics, structures, and system dynamics to name a few. The problem is that few researchers have experience in all these fields, and it is slow going while each advance gets integrated with the others. Helos may seem like simple machines that have been around for decades, but only in the last 10 years has helo theory taken center stage in many research institutions. So I am not surprised to see the envelope being pushed and I believe helos are going to occupy a much larger presence in military and commercial applications as the versatility, safety, and speed increases. Too bad I was not into them in school because they really are the subject to be in right now.

 

Another interesting addition to this area.

Sikorsky Announces Plan To Install Vibration Suppression System On Company Helicopters.

Flight International (10/14, Trimble) reported, "Sikorsky has revealed plans to install an advanced hub-mounted vibration suppression system (HMVS) on a company helicopter in the next 12 months that promises a 'jet-smooth' cabin experience." Jim Kagdis, programme manager for Sikorsky advanced programmes, stated, "We expect to drive this technology into all our products once its commercialisation is complete." "Vibration is a major concern for helicopter makers and owners. The constant buzzing can cause fatigue both to the crew and the cabin structure. Some helicopters use vibration isolators tuned to a predetermined in-plane frequency to passively cancel out vibration from the rotors and blades."