Sikorsky to Build World's Fastest Helicopter

ap2

3rd June 2005 - 11:29 AM

Sikorsky Aircraft today plans to build and test a demonstrator for a new class of coaxial X2 Technology helicopters that maintain or improve on all the vertical flight capabilities of rotorcraft and whose high speed configuration will cruise at 250 knots.

The top cruise speed of helicopters in service today, roughly 150 to 170 knots, are only incrementally better than what they were decades ago due to the fundamental limits of conventional rotor systems.

Sikorsky plans to build and fly its X2 Technology demonstrator helicopter at its Schweizer Aircraft subsidiary by the end of 2006. The X2 demonstrator will feature a coaxial design (two rotors on the same axis) and a "pusher prop" to supply auxiliary propulsion that will enable the aircraft to reach high speeds of 250 knots.

user posted image

kdqq

3rd June 2005 - 04:03 PM

Finally, something matching (and exceeding) Lockheed''s Cheyenne AH56A rigid-rotor helicopter, ca. 1967. It was the first helicopter that could fly upside-down, and used a unique mechanism to control blade pitch during rotation. As a member of Lockheed's Scouts, I got to crawl all through and over one, and helped work on a functional model.

More info: http://www.internetage.com/cartercopters/pics9.htm

NidStyles

3rd June 2005 - 11:18 PM

I hope they get with GE, and use some of those newer more efficient turbines they've been putting out there.

Al M

5th June 2005 - 12:01 AM

When I saw the title "Sikorsky to build World's Fastest Helicopter" I assumed it had a deal to build the Westland Lynx - which is the world's fastest helicopter but no, it just plans to build a helicopter which may beat the record.
Sikorsky must be pretty annoyed with Westland, what with the presidential helicopter contract going to them as well as the Canadian deals and so I can understand that they might try and beat this long established record.
I doubt they will achieve it - they haven't had much success with anything lately.

Leisure Meister

10th June 2005 - 07:15 PM

I hope they build them quick and attach cargo slings to them , then go snatch all the politicians up and drop them ova the ocean! Thankyou for your time.

Body Drop

23rd June 2005 - 04:30 PM

That ain't gonna work!
user posted image

Guest_Paul

30th August 2005 - 06:20 PM

Ok, maybe a very very stupid question. But since we're talking about the fastest helicopter

As a long time fan of the TV series Airwolf I am currently enjoying a heated debate how the rotor/jet system of Airwolf is 'supposed' to work. Now, I know it's only TV, but since 1984 we've come a long way in developing new aircraft.

Would it be possible to build a helicopter that disengages it's rotor system and ignites two additional jetengines and using the mainrotor (that keeps on turning through the airflow) for lift? Or would the rotor be torn off? We're talking speeds here of up to Mach 1.

Probably a really stupid question, but I am just interested in how it might or might not work. Aerodynamically speaking.

Thanks for any usable answers,

Cheers,

Paul.

Tfa

15th April 2006 - 08:50 AM

QUOTE (Guest_Paul+Aug 30 2005, 06:20 PM)

Ok, maybe a very very stupid question. But since we're talking about the fastest helicopter

As a long time fan of the TV series Airwolf I am currently enjoying a heated debate how the rotor/jet system of Airwolf is 'supposed' to work. Now, I know it's only TV, but since 1984 we've come a long way in developing new aircraft.

Would it be possible to build a helicopter that disengages it's rotor system and ignites two additional jetengines and using the mainrotor (that keeps on turning through the airflow) for lift? Or would the rotor be torn off? We're talking speeds here of up to Mach 1.

Probably a really stupid question, but I am just interested in how it might or might not work. Aerodynamically speaking.

Thanks for any usable answers,

Cheers,

Paul.

I know this is an old thread, but I'd also like to know about the feasability of this.

I had always been under the impression that it is due to the rotors approaching the speed of sound which effected this speed limit.

How does a pusher avert this problem?

Interested to here from someone who knows the physics behind this

Confused2

15th April 2006 - 09:55 AM

Like Tfa I thought the speed of sound was the limit on rotor speed.

Just a thought.. with one rotor.. as you go faster you have to keep your rotor speed high to get any lift on the 'slow' side so as not to flip over. With two rotors you have a 'fast' sweep on both sides. You get a boost from your forward speed so you can slow the rotors down. Maybe.

This could take us into plane on a conveyor belt territory

. No, please, it isn't!

-C2

.

samwize

29th May 2006 - 10:03 PM

QUOTE (Guest_Paul+Aug 30 2005, 06:20 PM)

Ok, maybe a very very stupid question. But since we're talking about the fastest helicopter

As a long time fan of the TV series Airwolf I am currently enjoying a heated debate how the rotor/jet system of Airwolf is 'supposed' to work. Now, I know it's only TV, but since 1984 we've come a long way in developing new aircraft.

Would it be possible to build a helicopter that disengages it's rotor system and ignites two additional jetengines and using the mainrotor (that keeps on turning through the airflow) for lift? Or would the rotor be torn off? We're talking speeds here of up to Mach 1.

Probably a really stupid question, but I am just interested in how it might or might not work. Aerodynamically speaking.

Thanks for any usable answers,

Cheers,

Paul.

hey i am a 15 year old and i am also a big fan of the 80,s tv show "airwolf". i have often pondered on your question about disingaging the rotor blades from the turbine then using anouther turbine producing thrust to go forward(basicaly turning it into a gyrocopter/gyroplane). in my opinion(considering the advances we have made in both helicopter and gyroplane teknolowgy) that this should be posible. i dont think it would reach mach 1 though. the sound barier would brobably rip the blades apart

Brent

21st June 2006 - 08:35 AM

Hello all,

There are a couple of considerations when dealing with high speed helicopters. It was "theorized" that the top speed possible of a rotary-wing aircraft is 250mph. The Lynx came extremely close with its 249mph run (that was a "slightly modified" Lynx). This speed is based on the fact that as you are traveling forward, with a big spinning airfoil over your head creating lift, you wind up with half of that airfoil going your airspeed plus the speed of the rotor through the air (ascending blade), and the other side (descending blade) going it's rotational speed minus your airspeed through the air.

The other half of the problem is that the ascending blade (side of the blade going the same direction through the air that you are) is going to go sonic, creating a shockwave and reducing usable lift to near zero. So you have one side going so slow, that it's not creating lift, and the other side going so fast that it isn't creating lift. Utilizing the lift vs weight property of flight... this is a formula for turning a helicopter into a cabin in which to skydive.

Now for "push" engines. This is feasible, but probably only for accelerating because of what is stated above. You would have to have a secondary airfoil for creating lift, once you got above 250mph, and then you have to consider the massive amount of drag that huge rotor is going to offer. So above 250mph you won't be able to count on the main rotor for much lift, but you will for a LOT of drag.

The other option it looks like Sikorsky is trying to use is stacking the rotors one on top of the other. In theory you could then cut the size of your rotor in half (area-wise not diameter-wise) to create the same lift. Reducing the size of the rotor makes it easier to not have that ascending blade go sonic (which is good) and also if you counter-rotate them (have them spin opposite directions) you limit the affect of the slower side not producing lift because you stagger that slower side. However, old research (I have heard of, but not seen) showed this idea to be ineffective, because the top blade creates so much turbulence, that it significantly reduces the effectiveness of the bottom rotor.

Last answer, top speed on the raptor with burners lit, is around Mach 2.7 est. Without burners 1.6 est. The SR-71's unclassified speed was "Mach 3.5 plus" The SR-71 still holds the official speed record, but many believe that the Top Secret "Aurora project" is a hypersonic pulse jet that runs on methane. This sounds like a possibility mixed with fantasy to me. You might want to look that up on yahoo or google if you are interested. Lastly, in hypersonic flight you don't have to worry about the "skin of the aircraft melting" like some people think is the problem. The biggest problems are the glass of the cockpit is going to go through a repeated tempering process and eventually break due to heat and pressure, and the expansion of the skin under the heat will cause wrinkles. The SR-71 was designed to deal with these things, so it will most likely hold the record for a while.

Brent

aaronoh

22nd June 2006 - 07:32 AM

Looks more like a submarine. How does 2 rotor help anyway. It look kind of creative.

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