This article first appeared at AviationWeek.com.
Sikorsky’s futuristic X2 high-speed helicopter technology demonstrator made its first flight today in Horseheads, N.Y., in the hands of chief test pilot Kevin L. Bredenbeck.
The single-engined fly-by-wire aircraft features coaxial rotors and a pusher propeller that Sikorsky believes will revolutionize the helicopter world with cruise speeds of up to 250 kts, some 100 kts faster than current production helicopters.
“This isn’t an airplane we are training to hover. It’s a helicopter that will go very, very fast,” said Sikorsky CEO Jeff Pino. “I think it will get to 260 kts.” (The helicopter world speed record is held by a Westland Lynx at 216.45 kts).
Today’s flight lasted 30 minutes, during which Bredenbeck demonstrated hover, forward flight, and a hover turn.
Current helicopter speeds are limited by rotor aerodynamics. In contrast the X2’s coaxial rotor system is optimized for all regimes of flight by a fly-by-wire control system that will slow the rotors at high forward speeds to prevent their tips going supersonic, while maximizing lift and minimizing drag by adjusting the pitch of the rigid, carbon-fiber blades. The counter-rotating rotors provide equal lift on each side of the aircraft and, unlike a traditional helicopter, are relieved of having to provide all the forward propulsion by a large pusher propeller at the rear of the fuselage.
The rigidity of the blades allows the rotors to be closely spaced only two feet apart, further reducing drag. Sikorsky believes the gap can be reduced even more in the future.
The X2 technology demonstrator is powered by a 1,452 shp, FADEC-equipped T800 turboshaft engine that was previously installed in one of the Comanche helicopter prototypes. It drives both the rotor and the pusher propeller through two gearboxes.
So far the aerospace industry’s solution to high speed, vertical flight has been the hugely complex tiltrotor, a hybrid airplane with rotors. The X2 differs markedly in that it is still a helicopter that can go fast, autorotate, hover, and fly nap of the earth.
The X2 can match the speed of the Bell/Agusta BA609 tiltrotor with far less complexity, according to Steve Estill, Sikorsky’s vice president for worldwide sales. X2 technology is especially well suited to missions such as flying fast to oil rigs, which would call for development of a light to intermediate X2 twin of the same size as the 12-passenger S-76 or 19-passenger S-92.
Read more about this story, see some gouge on the new laser JDAM, read about a new UAV called “saucer” and debate how much time is right for the new KC tanker from our Aviation Week friends at Military.com.
– Christian
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it would be hillarious if they obsoleted the ENTIRE justification for that stupid Osprey in one fell swoop
I wouldn’t bet on it. This may be a better helicopter than the Osprey, but the Osprey is a better airplane than this.
It WILL however be a great Osprey escort (think of a 200+ kt Cobra).
@Moose
Cobra came out of the Huey programme. Imagine the bastard child that would be an Osprey Gunship?!?!
Now that would be an appropriate Osprey escort. A Midget “Spectre”, that hovers if necessary.
Maybe Sikorsky could team up with Kamov Helicopters and apply this technology, along with western avionics & arms, to the KA-50 which already uses counter-rotating rotors. Kamov has previously teamed up with Israeli Aircraft Industries to create the KA-50–2 Erdogan.
Then again, with the stuff Russia is doing in Georgia…maybe we don’t want to upgrade any of their weapons systems.
Bell had a tiltrotor gunship idea that got as far as mockup stage years ago, and indeed it was ‘wicked cool’. (The two words I think of everytime I think of the photos of it).
The problem with helos is at any given time half your wings are going the wrong direction. The helo approach will always be less aerodynamically efficient in the horizontal plane no matter what you do, whereas the tilt-somethings get to put their thrust 100% in the direction they need it.
Pick your ‘complexity’ penalty and balance that against the ‘efficiency’ benefit for each alternative and follow what makes sense for your application.
Wahoo! Gotta love it.
The funny thing is that Horseheads, NY is a little rural town. The factory is rapidly coming the lifeblood of the Elmira/ Horseheads area.
You gotta love when your small home town makes something hi-tech that is national news.
irtusk,
Apples and oranges man, apples and oranges.
Build Commercial & Military models.
Make this Comanche 2 Gunship for Army & new the new MARINE ONE for the White House.
& replace the Huey?
Ideal Gunship, MedEvac, SAR, Cargo, passenger model.
Have computer controlled flt systems means anyone can Fly it.
( have bad coordination for stick, rudder, pedals & hover throttle in std copters).
Must make or use in estd copter systems.
What about stop rotor technology, i.e. the dragonfly, this has the potential for greater speed and efficiency due to using jet propulsion.
The capabilities of these systems could be compared to see which is more capable for a range of missions.
Wasnt there a pre-Apache gunship prototype with a pusher prop that got scuttled due to complexity? Of course it used a pusher, a tail roter, and a standard rotor…
Had 40mm and 20mm turrets in the concept as well IIRC.
What is the concern about rotor tips going supersonic?
Recall reading an article about the KA-50 a few years ago, but don’t recall the source (AW&ST?) Author stated that the KA-50 had, at that time, a problem with the upper & lower rotor blades colliding if the pilot attempted too tight a turn at high speed. The result, you can guess, was immediate falling out of the sky.
This wouldn’t be a problem in civilian use, but they’d have to keep the cost down to sell them.
@ hex16 “What is the concern about rotor tips going supersonic“
If the the tip goes super-sonic the resulting shockwave would tear(best description for lay person) the tip off, unless the whole thing was designed ALOT HEAVIER.
In the original teasting of supersonic jets they ended up with massive gouges in the air frame, if this happened in the thin and relatively light rotor blades the tips would tear off because extremely high pressure air would blast it’s way through the metal of the blade.
Kind of like sand blasting, in high speed. And through metal.
You don’t need to bother about having rigid rotors and making them counter-rotate if you go the Fairey Rotodyne route. With that, vertical flight was achieved with tip jets ducted from the main engines to eliminate torque, slow forward flight made the rotor work like an autogyro, and fast forward flight was practical because the wings provided most of the lift and unloaded the rotor enough that the blades didn’t need to adjust so much and the hingeing approach was still good enough. The Rotodyne managed speeds above 200 knots in the 1960s, so a modern development should be competitive even today.
Only one thing to say,
http://www.cartercopters.com/
I believe it will become a cheap version of Ospreys. This does not fly as fast as Ospreys, but cheaper to produce, cheaper to maintain. It would rather fit into the hi-lo mix with the Ospreys. The Ospreys would be the hi (quality approach) and the X-2 offsprings will be the lo (quantity approach). With a high price tag on Ospreys, a less speedy but lower price tag of the X-2 offsprings will provide quantities versus quality of the Ospreys, just like the hi-lo mix of Raptors and Lightning II.
>Now that would be an appropriate Osprey escort.
I had that in mind too. Probably not any other platform would achieve such high speed. It is not fast as Osprey, but faster than any other propelled VTOL excluding Osprey itself. Osprey has difficulties for weapon bays to be added due to the rotor blade being in the way. The X-2 offspring will have more freedom to add on weapon bays just like other helos. Both has advantages and disadvantages. These are not rivals, but something that would cover the weakness of the other.
RE Spencer:
Cartercopter is a joke. They break the mu=1 barrier than destroy their prototype and do nothing in the following 4 years.
You other guys have to realize that this craft is just a technology demonstrator. We created this as a platofrm to study the entire concept to be applied to specific mission profiles. Actually, the army re-funded X2 research for JHL, after they had claimed in 2006 that they were only looking at tilt rotor solutions. The X2 tech package looks promising, and our concepts utilize it in an osprey sized aircraft which, if you may recall, can autorotate…as all X2 based designs can.
I appreciate Sikorsy’s efforts; but if you look at this:
http://www.gizmag.com/falx-to-debut-hybrid-electric-tilt-rotor-aircraft-with-inbuilt-solar-c/9234/
You realize that even with it still on the drawing board, this design is going to make helicopters and the Osprey so much overcomplicated / obsolete junk.….
Sikorsky needs to not make the same mistake the railroads did, they are not in the business of railroads, but of transporting things. With this thought in mind you would think the rail barons would have started truck and aircraft companies.
No, most of them just went out of business.…
I think the helicopter is not long for this world
Dennis, read the opening line of your link which talks about tilt rotors being around since the 50s. Look at how many tilt rotors have been operational during that time vs. helicopters that originated around the same timeframe.
Look at the 900 lb weight of your air vehicle which increases by 200–400 lbs with pilot(s). Look at the measley 100 hp engine to power the batteries driving the electric motors. Show me an electric car or hybrid that weighs the same as the high performance conventional engine.
Finally, check out the powerpoint that I posted in the UH-60M article above and see how aircraft with equivalent power have much different payloads depending on whether helicopter or tilt rotor. Hint.…the tilt rotor never wins.
Now look at this little X2 gem with 8 blades producing lift in a much smaller rotor diameter allowing enhanced lift in a small LZ with similar to tilt rotor speeds. Methinks that rumors of the demise of helicopters are more than a bit exaggerated.
Why not just make an x2 comanche. Then you have an escort for the JHL. Most of the research for the comanche has been paid for. Why not use it in the next generation attack helicopter?
Greg
What makes you think that Comanche tech has not made its way in to X2, S76D, H92, UH60, CH53K etc?
Again, I think a lot of you guys on here keep forgetting that this craft is just a technology demonstrator. It will never be produced in this configuration.
If the goal is to produce prototypes, it seems like Piasecki has already been here and has a leg up on Sikorski. Last year, Piasecki (originator of the dual rotor system that led to the YH-16, CH-46 and the CH-47) under contract to the ARMY completed their phase-one demonstration of a vectored-thrust compound helicopter using a significantly larger, Sikorski UH-60 airframe. For their design, they retrofitted a ducted fan and wing stubs onto an BlackHawk airframe and proved enhanced speed and vibration performance. As for looks and appearance, this airframe looks much closer to what you would expect from a vertical craft too as opposed to having the dual rotors on top of each others.