Sikorsky X2 coaxial heli developments.
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Hi John,
No, neither of them. Nick got to fly the XH-59B and said that he was really impressed.
WOW! Thanks for the response.
My method is to drop the subject and very quickly move on to a different one.
Dave
I am curious, Dave: have you ever seen the ABC up close, in person?
I was therefore wrong in stating that the 61F was a company funded design.
My method is to drop the subject and very quickly move on to a different one.
Dave
Dave,
I saw the ABC from inside and out. The first thing I noted was that the majority of the cabin was taken up with transmission. Maybe Sikorsky could dispell this by showing what is behind the pilot on the X-2. The tilt rotors put less complex transmissions on the wings and free up the entire fuselage for useful load.
The Sultan
I saw the ABC from inside and out. The first thing I noted was that the majority of the cabin was taken up with transmission. Maybe Sikorsky could dispell this by showing what is behind the pilot on the X-2. The tilt rotors put less complex transmissions on the wings and free up the entire fuselage for useful load.
The Sultan
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TS,
Directly behind the rear pilot's area in the X2 are the force generators.
The AeroVantage puts the PropRotors fore & aft and frees up the entire area for downwash.
-
The devil made me do it, 'cause I don't have a large marketing budget. 
Dave
Directly behind the rear pilot's area in the X2 are the force generators.
__________________________
The tilt rotors put less complex transmissions on the wings and free up the entire fuselage for useful load.
-
The devil made me do it, 'cause I don't have a large marketing budget. Dave
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Some interesting technical discussion going on here! 
Good point about ABC fuselage being taken up by transmission. In principle, since each rotor only handles half the torque in hover over conventional, i am not sure why ABC would require a significantly larger transmission. The only reason i can think of is that each rotor would need to handle more torque during high speed manouvre, because advancing and roll upwards side doing more lift. The shaft and hub mechanisms would clearly need to be much stiffer/stronger, but this is true of any high effective hinge offset rotor.
Although inherently good lateral Cm comes naturally with tilt-rotor, i suspect that this would be offset by the need for more power/torque for the higher disc loading. I have no figures to compare on this point.
Dave, that's a handy resource you have there. Any chance of the two technical papers you mention?
1. Aerodynamic Design of the X2 TD Main Rotor Blade - Ashish Bagai (May 2008)
2. Dynamic Design Characteristics of the Sikorsky X2 TD Aircraft - R. Blackwell
(May 2008)
PS: Hardly even get time to check this site out now...
Mart
Good point about ABC fuselage being taken up by transmission. In principle, since each rotor only handles half the torque in hover over conventional, i am not sure why ABC would require a significantly larger transmission. The only reason i can think of is that each rotor would need to handle more torque during high speed manouvre, because advancing and roll upwards side doing more lift. The shaft and hub mechanisms would clearly need to be much stiffer/stronger, but this is true of any high effective hinge offset rotor.
Although inherently good lateral Cm comes naturally with tilt-rotor, i suspect that this would be offset by the need for more power/torque for the higher disc loading. I have no figures to compare on this point.
Dave, that's a handy resource you have there. Any chance of the two technical papers you mention?
1. Aerodynamic Design of the X2 TD Main Rotor Blade - Ashish Bagai (May 2008)
2. Dynamic Design Characteristics of the Sikorsky X2 TD Aircraft - R. Blackwell
(May 2008)
PS: Hardly even get time to check this site out now...
Mart
Dave,
Have you seen this article about the SpeedHawk concept being applied to the Chinook?
Very similar concept to what you offered....but with less colorful drawings.
Patent alert: Chinook augmented by vectored thrusters - The DEW Line
Have you seen this article about the SpeedHawk concept being applied to the Chinook?
Very similar concept to what you offered....but with less colorful drawings.
Patent alert: Chinook augmented by vectored thrusters - The DEW Line
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Mart,
You've got mail.
SASless,
Had not seen. Thanks.
It would be interesting to see a performance comparison between it and this. Boeing 347, Tandem w/ wing
Dave
You've got mail.
SASless,
Had not seen. Thanks.
It would be interesting to see a performance comparison between it and this. Boeing 347, Tandem w/ wing
Dave
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Interesting articles SASless & Ian.
There may also be a good case for developing ABC tandems, since the powertrain layout is already there. There would be a weight penalty because the high hinge offset rotors would load up the transmission, and the fuselage would also be loaded in torsion. I imagine the loss of payload would still allow a good payload mass-speed product.
Anyone know how much Chinook powertrain weighs? An initial guestimate would be to double powertrain mass (since engine power also goes up), and see how much payload/fuel capability is eaten up...
There may also be a good case for developing ABC tandems, since the powertrain layout is already there. There would be a weight penalty because the high hinge offset rotors would load up the transmission, and the fuselage would also be loaded in torsion. I imagine the loss of payload would still allow a good payload mass-speed product.
Anyone know how much Chinook powertrain weighs? An initial guestimate would be to double powertrain mass (since engine power also goes up), and see how much payload/fuel capability is eaten up...
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Thanks, Dan.
Always interesting to hear the TPs comments.
Some interesting commercial aviation potential there too.
Notice how there is a reducer g/box for the tail prop, with d/shaft coming in along starboard side. I assume/guess the clutch is near the main g/box, while the pitch mech is in the tail g/box. It's always good to get a peak at the powertrain installation...
Always interesting to hear the TPs comments.
Some interesting commercial aviation potential there too.
Notice how there is a reducer g/box for the tail prop, with d/shaft coming in along starboard side. I assume/guess the clutch is near the main g/box, while the pitch mech is in the tail g/box. It's always good to get a peak at the powertrain installation...
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After watching Alexander Korda's 1936 big screen interpretation of H.G. Wells' "Things to Come" on TCM last night, I discover that Sikorsky has been working on the X2 concept for over 70 years now...
Wells/Korda apparently had little faith in the coaxial rotor, preferring a more conventional layout instead. Still, the good news is that the program seems to be ahead of schedule - Wells predicted that the concept wouldn't appear until 2036...
I/C
Wells/Korda apparently had little faith in the coaxial rotor, preferring a more conventional layout instead. Still, the good news is that the program seems to be ahead of schedule - Wells predicted that the concept wouldn't appear until 2036...
I/C
Last edited by Ian Corrigible; 28th Aug 2014 at 15:22.
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X2 Needs runway not heliport for landings!?!?
(Westland sour grapes?)
Historic helicopter venture zooming to town
By STACEY SINGER
Palm Beach Post Staff Writer
Monday, April 13, 2009
In a place where eagles and ospreys soar, a helicopter tarmac awaits an exceptionally rare bird.
Sikorsky Aircraft Corp. is about to truck its one-of-a-kind X2 helicopter prototype to an airfield 12 miles west of West Palm Beach, where the aircraft will try to break the helicopter speed record.
Sikorsky Aircraft's schedule calls for the X2 to pass the 250-knot mark — 287 miles per hour — by year's end. It would make the X2 the fastest helicopter and shatter the belief that helicopters cannot exceed 250 mph without spinning out of control.
The Sikorsky Aircraft Development Flight Center is tucked between the J.W. Corbett Wildlife Management Area and the Beeline Highway, off the radar of most. Despite its low profile, the West Palm Beach-area flight center has become a winner in a difficult economy.
In its 20-year history in South Florida, Sikorsky Aircraft has never employed as many people as it does now. In 2008, the firm added 365 workers, bringing its head count to 878, said General Manager Pete Ladyko.
Part of United Technologies, Sikorsky Aircraft's home is in Stratford, Conn. The addition of the X2 to its local operation will require several Connecticut-based employees to relocate here, at least temporarily, Ladyko said, but it won't add substantially to the number of local workers.
Most local Sikorsky employees are building next-generation Black Hawks and the aircraft that Canada is using to replace its aging maritime helicopter fleet, the CH-148 Cyclone.
Others are test pilots and engineers dedicated to refining and customizing models such as the 19-passenger luxury bus called the S-92, often used to carry workers to oil platforms. Five aircraft development programs are in testing here.
Last week's budget briefing from Defense Secretary Robert Gates suggested the company would continue to grow under the Obama administration. Gates said helicopters are "in urgent demand in Afghanistan."
Thirty to 35 UH60-M Black Hawk helicopters are made each year near West Palm Beach, Ladyko said.
The next-generation Black Hawks, like the X2 and Canada's CH-148, feature a computer technology called "fly-by-wire" that replaces mechanical controls with digital ones. The fly-by-wire software must be refined in test flights.
Test pilot Rick Becker handled the controls for the first flight of the CH-148 near West Palm Beach in November. The systems had been analyzed for more than 100 hours on the ground before going airborne, Becker said.
"It does have an exhilarating quality to it the first time you lift off, but it's the logical culmination of what we've been doing," he said. "You build up to it."
A similar process is under way for the X2.
The X2's first flight was Aug. 27 at the Sikorsky-Schweizer Hawk Works near Elmira, N.Y. The pilot initially ran the aircraft at slow speeds, assessing stability and basic systems.
The helicopter speed barrier could be breached this summer after the X2's unusual boat-like pusher-propeller is tested.
Most helicopter designs include a tail rotor that counters a helicopter's tendency to rotate opposite the blades' direction. Having twin rotors gives the same balance and means the tail can be freed to push the aircraft forward at high speeds. It also gives maneuverability and enables the aircraft to carry up to 40 tons, according to the journal Aerospace Testing International.
Sikorsky Aircraft says the X2 is designed to "cruise comfortably" at 287 mph. That would be exceptional.
"The speed record for any helicopter is held by the Westland Lynx at 249 mph, or about 220 knots, but this was a one-time record," said helicopter pilot R. Randall Padfield, the editor of Aviation International News.
That Westland Lynx sits in a museum today.
Breaking the helicopter speed barrier would be exciting. Will the market embrace it?
Padfield is skeptical because the X2 needs a runway for landings rather than a heliport.
"I think the market is not as great as helicopter promoters like to say it is," Padfield said.
The X2 is intended to lead to development of a commercial or military aircraft. Its ultimate price is unknown. Sikorsky Aircraft is paying for the X2's development, a company representative said.
http://www.palmbeachpost.com/localnews/content/local_news/epaper/2009/04/12/a1a_sikorsky_0413.html
Historic helicopter venture zooming to town
By STACEY SINGER
Palm Beach Post Staff Writer
Monday, April 13, 2009
In a place where eagles and ospreys soar, a helicopter tarmac awaits an exceptionally rare bird.
Sikorsky Aircraft Corp. is about to truck its one-of-a-kind X2 helicopter prototype to an airfield 12 miles west of West Palm Beach, where the aircraft will try to break the helicopter speed record.
Sikorsky Aircraft's schedule calls for the X2 to pass the 250-knot mark — 287 miles per hour — by year's end. It would make the X2 the fastest helicopter and shatter the belief that helicopters cannot exceed 250 mph without spinning out of control.
The Sikorsky Aircraft Development Flight Center is tucked between the J.W. Corbett Wildlife Management Area and the Beeline Highway, off the radar of most. Despite its low profile, the West Palm Beach-area flight center has become a winner in a difficult economy.
In its 20-year history in South Florida, Sikorsky Aircraft has never employed as many people as it does now. In 2008, the firm added 365 workers, bringing its head count to 878, said General Manager Pete Ladyko.
Part of United Technologies, Sikorsky Aircraft's home is in Stratford, Conn. The addition of the X2 to its local operation will require several Connecticut-based employees to relocate here, at least temporarily, Ladyko said, but it won't add substantially to the number of local workers.
Most local Sikorsky employees are building next-generation Black Hawks and the aircraft that Canada is using to replace its aging maritime helicopter fleet, the CH-148 Cyclone.
Others are test pilots and engineers dedicated to refining and customizing models such as the 19-passenger luxury bus called the S-92, often used to carry workers to oil platforms. Five aircraft development programs are in testing here.
Last week's budget briefing from Defense Secretary Robert Gates suggested the company would continue to grow under the Obama administration. Gates said helicopters are "in urgent demand in Afghanistan."
Thirty to 35 UH60-M Black Hawk helicopters are made each year near West Palm Beach, Ladyko said.
The next-generation Black Hawks, like the X2 and Canada's CH-148, feature a computer technology called "fly-by-wire" that replaces mechanical controls with digital ones. The fly-by-wire software must be refined in test flights.
Test pilot Rick Becker handled the controls for the first flight of the CH-148 near West Palm Beach in November. The systems had been analyzed for more than 100 hours on the ground before going airborne, Becker said.
"It does have an exhilarating quality to it the first time you lift off, but it's the logical culmination of what we've been doing," he said. "You build up to it."
A similar process is under way for the X2.
The X2's first flight was Aug. 27 at the Sikorsky-Schweizer Hawk Works near Elmira, N.Y. The pilot initially ran the aircraft at slow speeds, assessing stability and basic systems.
The helicopter speed barrier could be breached this summer after the X2's unusual boat-like pusher-propeller is tested.
Most helicopter designs include a tail rotor that counters a helicopter's tendency to rotate opposite the blades' direction. Having twin rotors gives the same balance and means the tail can be freed to push the aircraft forward at high speeds. It also gives maneuverability and enables the aircraft to carry up to 40 tons, according to the journal Aerospace Testing International.
Sikorsky Aircraft says the X2 is designed to "cruise comfortably" at 287 mph. That would be exceptional.
"The speed record for any helicopter is held by the Westland Lynx at 249 mph, or about 220 knots, but this was a one-time record," said helicopter pilot R. Randall Padfield, the editor of Aviation International News.
That Westland Lynx sits in a museum today.
Breaking the helicopter speed barrier would be exciting. Will the market embrace it?
Padfield is skeptical because the X2 needs a runway for landings rather than a heliport.
"I think the market is not as great as helicopter promoters like to say it is," Padfield said.
The X2 is intended to lead to development of a commercial or military aircraft. Its ultimate price is unknown. Sikorsky Aircraft is paying for the X2's development, a company representative said.
http://www.palmbeachpost.com/localnews/content/local_news/epaper/2009/04/12/a1a_sikorsky_0413.html
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Having twin rotors gives the same balance and means the tail can be freed to push the aircraft forward at high speeds. It also gives maneuverability and enables the aircraft to carry up to 40 tons, according to the journal Aerospace Testing International.
Maybe the X2 needs a runway when it is loaded up to 40 tons, like it says in the article. That would seem to be a pretty good tradeoff to me. I don't know where they would fit 40 tons though. Time to call in Dr. Who.
Aero-news had a little interpretation of the article too:
Sikorky's X2 Expected To Conduct Speed Trials In West Palm Beach
Funny how they call it a helicopter/airplane hybrid. Where are the wings?
-- IFMU
Aero-news had a little interpretation of the article too:
Sikorky's X2 Expected To Conduct Speed Trials In West Palm Beach
Funny how they call it a helicopter/airplane hybrid. Where are the wings?
-- IFMU
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The Aerospace Testing International article, which was mentioned in the Palm Beach Post article.
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X2 has already demonstrated the ability to hover in flight test.
Much better to stop then land, than land then stop...
When X2 does what it was designed to do i have no doubt that the world will beat a path to Sikorsky/Schweizers door. Take a good design concept, identify the limitations, and evolve the concept. Sounds like a recipe for success to me - i'll certainly be excited when that magic 250kts is reached!
Much better to stop then land, than land then stop...
When X2 does what it was designed to do i have no doubt that the world will beat a path to Sikorsky/Schweizers door. Take a good design concept, identify the limitations, and evolve the concept. Sounds like a recipe for success to me - i'll certainly be excited when that magic 250kts is reached!
Last edited by Graviman; 14th Apr 2009 at 11:50. Reason: Typo
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CEFOSKEY,
I've done some traditional back of envelope calcs to convince myself that scaling up X2 technology is feasible (i did waver earlier in the thread). As the rotor diam goes up 1st flap and torsion frequencies linearly reduce, but so does NR (for constant tip speed). So any offset hinge achievable with X2 would also apply to the scaled up machine. The technology is scalable.
Interesting to see whether faster point-to-point passenger service becomes a driver for the technology...
I've done some traditional back of envelope calcs to convince myself that scaling up X2 technology is feasible (i did waver earlier in the thread). As the rotor diam goes up 1st flap and torsion frequencies linearly reduce, but so does NR (for constant tip speed). So any offset hinge achievable with X2 would also apply to the scaled up machine. The technology is scalable.
Interesting to see whether faster point-to-point passenger service becomes a driver for the technology...
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That looks pretty sweet!
truth is I would love to see a medical version of one of these go screaming by on its way to the Hospital Medical helicopters give me my daily fix
truth is I would love to see a medical version of one of these go screaming by on its way to the Hospital
Medical helicopters give me my daily fix