Sikorsky X2 coaxial heli developments.
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I have not yet flipped through all of the thread pages for the X2..........A pilot associate from rotor space suggested this web site to me.........so I'm a Newby. Anyway, I have seen several pictures of the X2 and my question is does the X2 have adjusable mast incidence....+/- tilt forward or aft?????? Reason I ask is some pics seem to show the bottom rotor blades closer to the forward fuselage than in others? Anyone know? Thanx,
Regards,
D. Hickman
Regards,
D. Hickman
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It looks like the X2 and other high-speed rotorcraft concepts now will have a DOD program of record. According to this Aviation Week article, an Army AMRDEC spokesman stated that the JMR rotorcraft program is funded to produce two different prototype aircraft (likely a tilt rotor and a compound helo) for a fly-off in FY'17. The program will kick-off with concept studies in mid FY'11.
Since the X2 is already flying, Sikorsky has an excellent shot at one of the two TD contracts.
riff_raff
Since the X2 is already flying, Sikorsky has an excellent shot at one of the two TD contracts.
riff_raff
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davh12,
The advantage of X2 is that it seperates out lift and thrust. The main rotor is a fixed incidence design, which means that for emergency autorotation all you need to do is drop collective pitch. This means that despite its speed capability it can still perform all of the tasks a conventional helicopter can - only faster. You pay for the performance benefit with the increased weight of a coaxial rotor system, which means a slight reduction in payload for a given mission. On the other hand, for your line of work, it means the bad guy has less time to react...
The advantage of X2 is that it seperates out lift and thrust. The main rotor is a fixed incidence design, which means that for emergency autorotation all you need to do is drop collective pitch. This means that despite its speed capability it can still perform all of the tasks a conventional helicopter can - only faster. You pay for the performance benefit with the increased weight of a coaxial rotor system, which means a slight reduction in payload for a given mission. On the other hand, for your line of work, it means the bad guy has less time to react...
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yeah..."tandem double stack"...it is tandem right..........two sets of propeller thingys...lol
.........
. That's about as insightful as hoping that God will put a "post it" sticker on your bird when it's time for preventive maintenance
.......... That's about as insightful as hoping that God will put a "post it" sticker on your bird when it's time for preventive maintenance
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I've heard the X2 dubbed an "absolute rigid rotor system"........it may have been discussed in this thread since 2006........been going on a while, but I'm not patient enough to read through every post in the past 3 or 4 years. That being said, if it is an absolute rigigd rotor system, how does it over come dissmmetry of lift?
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Rigid refers to the hub design - implying that there are no flap or lead-lag hinges, only feathering hinges. Flap and lead-lag forces are absorbed by the material in the rotor head.
Good question- I'm in West Palm Beach for a special press thingy on the X-2 tomorrow, and have a ton of questions - it's for an article in Vertical in the very near future!
Good question- I'm in West Palm Beach for a special press thingy on the X-2 tomorrow, and have a ton of questions - it's for an article in Vertical in the very near future!
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Just out of curiosity... with all the fanfare of the X2 breaking the Heli speed record, how does anyone figure the X2, a compound helicopter, can be compared to the current (or previous) record holding Lynx, which achieved the speed record without any thrusting appendages?
And if it did indeed steal the record and non rotor system thrust is allowed, would it not still be trying to catch up the Bell 533, which hit almost 275 knots back in 1969?
Mike
And if it did indeed steal the record and non rotor system thrust is allowed, would it not still be trying to catch up the Bell 533, which hit almost 275 knots back in 1969?
Mike
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Shawn,
You may wish to ask Sikorsky about the mast fairing, which is yet to be installed.
Two patents;
7,607,607 ~ De-rotation system suitable for use with a shaft fairing system, and
7,621,480 ~ De-rotation system for a counter-rotating, coaxial rotor hub shaft fairing
show many potential mechanical and electrical means of limiting its rotation.
Apparently, the uncontrolled rotation of the mast faring is due to the fact that it is located between a clockwise rotating rotorhub and a counter-clockwise rotating rotorhub. It appears that there is nothing stationary to attach mast fairing to.
Dave
P.S. If you want to be mischievous, you can ask them if the Intermeshing-ABC has a mast.
You may wish to ask Sikorsky about the mast fairing, which is yet to be installed.
Two patents;
7,607,607 ~ De-rotation system suitable for use with a shaft fairing system, and
7,621,480 ~ De-rotation system for a counter-rotating, coaxial rotor hub shaft fairing
show many potential mechanical and electrical means of limiting its rotation.
Apparently, the uncontrolled rotation of the mast faring is due to the fact that it is located between a clockwise rotating rotorhub and a counter-clockwise rotating rotorhub. It appears that there is nothing stationary to attach mast fairing to.
Dave
P.S. If you want to be mischievous, you can ask them if the Intermeshing-ABC has a mast.
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Chop Chop
the next step ??
the next step ??
"Expect something from Sikorsky inside a couple of months", company manager for advanced programs Jim Kagdis said at the International Powered Lift Conference in Philadelphia on Tuesday. As the X2 program winds down - the demonstrator is designed for a limited life, and Sikorsky plans to place it with the Smithsonian after a couple more sorties - the company is pitching the idea of replacing the Army's Kiowa Warriors and Special Forces AH-6 and MH-6 Little Birds with an X2-technology aircraft.
That is also the goal of the Army's Armed Aerial Scout program, currently in the analysis of alternatives stage with a report due next year.
Sikorsky showed a full-scale mockup of its Light Tactical Helicopter (LTH) design at last year's Association of the US Army convention in Washington DC, but Kagdis would not be drawn on whether the company plans to announce a new initiative at the 2011 event later this month.
Kagdis said that the company sees the LTH as having the most potential for an early transition of the X2 to production. He also stressed that the X2 concept is not just about speed: the program started with four key performance parameters (speed, low workload, low vibration and low noise) and that as the project progressed, the company recognized also that the high power required for speed woulkd translate into much improved hot-and-high performance.
The X2 just completed some acoustic tests with the pusher propeller shut down and the speed of the main rotors reduced. Its remaining tasks include testing a "sail" fairing on the rotor mast - not to increase speed but to reduce drag at speed, critical to achieving long range with a coaxial design.
Kagdis did not hand out copies of his IPLC presentation, but outlined an LTH with a normal takeoff weight of 8950 pounds and a max of 10500 pounds (about the size of a classic AH-1G Cobra), powered by a single 3,000 hp engine. Despite its size, the relatively small rotor diameter (33 feet) and lack of a tail rotor give it an "operating length" between that of the Kiowa Warrior and the Little Bird, while the high installed power allows it to hover at 14,000 feet - today's helicopters, Kagdis says, cannot hover over 40 per cent of Afghanistan, but the LTH can cover 97 per cent of the country.
Small size would make it easier to operate in mountains or urban canyons, the ability to pull 2.9 g turns would cut turn radius, and the X2 layout can (unlike a conventional helicopter) accelerate and decelerate in a flat attitude.
It's an interesting prospect, An early LTH program would depend on the Army's ability to find the money and the politics of a competition - as in the early days of the V-22 program, the problem is that no US company other than Sikorsky has a comparable aircraft at the same maturity level.
But the Connecticut company is clearly preparing to take a shot at jump-starting rotorcraft development. If I was doing it, I'd think about a teaming arrangement, and I'd go with Boeing and its tool-kit of Apache and AH-6 pieces.
That is also the goal of the Army's Armed Aerial Scout program, currently in the analysis of alternatives stage with a report due next year.
Sikorsky showed a full-scale mockup of its Light Tactical Helicopter (LTH) design at last year's Association of the US Army convention in Washington DC, but Kagdis would not be drawn on whether the company plans to announce a new initiative at the 2011 event later this month.
Kagdis said that the company sees the LTH as having the most potential for an early transition of the X2 to production. He also stressed that the X2 concept is not just about speed: the program started with four key performance parameters (speed, low workload, low vibration and low noise) and that as the project progressed, the company recognized also that the high power required for speed woulkd translate into much improved hot-and-high performance.
The X2 just completed some acoustic tests with the pusher propeller shut down and the speed of the main rotors reduced. Its remaining tasks include testing a "sail" fairing on the rotor mast - not to increase speed but to reduce drag at speed, critical to achieving long range with a coaxial design.
Kagdis did not hand out copies of his IPLC presentation, but outlined an LTH with a normal takeoff weight of 8950 pounds and a max of 10500 pounds (about the size of a classic AH-1G Cobra), powered by a single 3,000 hp engine. Despite its size, the relatively small rotor diameter (33 feet) and lack of a tail rotor give it an "operating length" between that of the Kiowa Warrior and the Little Bird, while the high installed power allows it to hover at 14,000 feet - today's helicopters, Kagdis says, cannot hover over 40 per cent of Afghanistan, but the LTH can cover 97 per cent of the country.
Small size would make it easier to operate in mountains or urban canyons, the ability to pull 2.9 g turns would cut turn radius, and the X2 layout can (unlike a conventional helicopter) accelerate and decelerate in a flat attitude.
It's an interesting prospect, An early LTH program would depend on the Army's ability to find the money and the politics of a competition - as in the early days of the V-22 program, the problem is that no US company other than Sikorsky has a comparable aircraft at the same maturity level.
But the Connecticut company is clearly preparing to take a shot at jump-starting rotorcraft development. If I was doing it, I'd think about a teaming arrangement, and I'd go with Boeing and its tool-kit of Apache and AH-6 pieces.
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A triple sleeve mast with the centre sleeve stationary and providing support for the other sleeves could serve as an adequate mount point for the mast fairing.
"During forward flight, airflow stabilizes the shaft fairing on the bearing arrangement relative the rotating interconnecting main rotor shaft. During hover and low speed maneuvers, however, frictional forces acting on the bearing arrangement may tend to cause the shaft fairing to undesirably rotate in unison with the main rotor system. Rotation of the shaft fairing may increase drag and reduce the low-observability benefits of the contoured shaft fairing."
This is one of the proposed solutions on US 7,607,607.
Other ideas cover various means of getting the electrical power, plus the sensory and control instructions into this fairing.
Dave
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I had wondered about the fairing rotating with the mast. The solution is obvious: fit a gear to the underside of top rotor and topside of lower rotor and have a differential system in the mounting system for the fairing. These needn't be heavy since no actual load is to be carried other than sticktion in fairing bearings. Of course it would require rotor system to be dismantled with whatever procedures are required for an airworthy machine. Probably we won't see it fitted in flight - a real shame in my opinion.
It would be nice if fairing was fitted when machine is presented in the Smithsonian - if only as an aknowledging nod towards the difference between concept and development.
It would be nice if fairing was fitted when machine is presented in the Smithsonian - if only as an aknowledging nod towards the difference between concept and development.
Last edited by Graviman; 22nd Oct 2010 at 11:47.
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Just back from the demonstration at West Palm Beach. Impressive display.
Sikorsky also unveiled the X-49 as a company funded project for two demonstrators to be flown within 4 years. Gutsy!
More in a not-too-distant issue of Vertical!
Sikorsky also unveiled the X-49 as a company funded project for two demonstrators to be flown within 4 years. Gutsy!
More in a not-too-distant issue of Vertical!
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cattletruck,
Yes, you are basically correct. However, the two patents cover many electric and mechanical means of setting the azimuth of the fairing. Plus, a variety of control methods, since the may want to select different azimuths for different flight conditions.
Dave
Does that mean the mast fairing would be electrically stabilised in its proper position during low forward speed?
Dave
-- IFMU
Sikorsky Commits to Build X2 Technology Prototypes to Advance Military Rotary Wing Operations
Wednesday, October 20, 2010 - Sikorsky
WEST PALM BEACH, Fla.,– Sikorsky Aircraft will design, build and fly two prototype light tactical helicopters as the follow-on advancement to the X2 TechnologyTM demonstrator aircraft that unofficially shattered the helicopter world speed record here in September with a flight speed of 250 knots (287 mph). The decision to continue development of the next-generation rotary wing technology will enable Sikorsky and select suppliers to offer the high speed X2 prototype vehicles for flight test and evaluation by U.S. armed forces. Sikorsky Aircraft is a subsidiary of United Technologies Corp. (NYSE: UTX).
“Having proved the X2 Technology design to ourselves, we have full confidence we can now mature the technology for the U.S. Army’s light armed reconnaissance helicopter size,” said Sikorsky President Jeffrey Pino. “Self funding the design of a brand new light tactical helicopter – the Sikorsky S-97 – and manufacturing two prototypes we have designated as the Raider&™ X2 helicopter will help military aviation evaluate the viability of a fast and maneuverable next generation rotorcraft for a variety of combat missions.”
In March 2010, Sikorsky submitted an X2 aircraft design to the Army’s Armed Aerial Scout (AAS) program in response to a request for information. The AAS program is currently conducting an analysis of alternatives for the Army’s next armed reconnaissance helicopter.
Like the X2 Technology demonstrator that unofficially broke the helicopter speed record, the X2 Raider prototypes will feature twin coaxial counter-rotating main rotors (in place of one main rotor and a tail rotor) and a pusher propeller.
For the armed reconnaissance mission, the X2 Raider helicopter will have space aft of the two-pilot cockpit for armament and auxiliary fuel. In an assault configuration, the cabin affords space to accommodate up to six troops.
In addition to flying at nearly twice the speed of a conventional helicopter, the X2 Raider prototype aircraft will incorporate other key performance parameters critical to combat operations — increased maneuverability, greater endurance, and the ability to operate at high altitudes.
Compared to other light military helicopters, the X2 Raider prototypes are expected to significantly reduce turning radius and acoustic noise signature, while significantly increasing the aircraft’s payload, flight endurance and hot and high hover capability.
“These attributes will enable the X2 Raider aircraft to meet or exceed the potential U.S. Army requirements for its next armed reconnaissance helicopter,” said Doug Shidler, Sikorsky’s Light Tactical Helicopter director. “If selected by the Army, the X2 Raider aircraft design will enable high performance flight operations in high altitude regions that currently pose challenges to today’s light military helicopters.”
Sikorsky will conduct its X2 Raider aircraft development program utilizing military standards. The company expects to conduct its first major program milestone — a preliminary design review — in 2011. First flight, projected in four years, could depend in part on the pace of development and customer need.
Wednesday, October 20, 2010 - Sikorsky
WEST PALM BEACH, Fla.,– Sikorsky Aircraft will design, build and fly two prototype light tactical helicopters as the follow-on advancement to the X2 TechnologyTM demonstrator aircraft that unofficially shattered the helicopter world speed record here in September with a flight speed of 250 knots (287 mph). The decision to continue development of the next-generation rotary wing technology will enable Sikorsky and select suppliers to offer the high speed X2 prototype vehicles for flight test and evaluation by U.S. armed forces. Sikorsky Aircraft is a subsidiary of United Technologies Corp. (NYSE: UTX).
“Having proved the X2 Technology design to ourselves, we have full confidence we can now mature the technology for the U.S. Army’s light armed reconnaissance helicopter size,” said Sikorsky President Jeffrey Pino. “Self funding the design of a brand new light tactical helicopter – the Sikorsky S-97 – and manufacturing two prototypes we have designated as the Raider&™ X2 helicopter will help military aviation evaluate the viability of a fast and maneuverable next generation rotorcraft for a variety of combat missions.”
In March 2010, Sikorsky submitted an X2 aircraft design to the Army’s Armed Aerial Scout (AAS) program in response to a request for information. The AAS program is currently conducting an analysis of alternatives for the Army’s next armed reconnaissance helicopter.
Like the X2 Technology demonstrator that unofficially broke the helicopter speed record, the X2 Raider prototypes will feature twin coaxial counter-rotating main rotors (in place of one main rotor and a tail rotor) and a pusher propeller.
For the armed reconnaissance mission, the X2 Raider helicopter will have space aft of the two-pilot cockpit for armament and auxiliary fuel. In an assault configuration, the cabin affords space to accommodate up to six troops.
In addition to flying at nearly twice the speed of a conventional helicopter, the X2 Raider prototype aircraft will incorporate other key performance parameters critical to combat operations — increased maneuverability, greater endurance, and the ability to operate at high altitudes.
Compared to other light military helicopters, the X2 Raider prototypes are expected to significantly reduce turning radius and acoustic noise signature, while significantly increasing the aircraft’s payload, flight endurance and hot and high hover capability.
“These attributes will enable the X2 Raider aircraft to meet or exceed the potential U.S. Army requirements for its next armed reconnaissance helicopter,” said Doug Shidler, Sikorsky’s Light Tactical Helicopter director. “If selected by the Army, the X2 Raider aircraft design will enable high performance flight operations in high altitude regions that currently pose challenges to today’s light military helicopters.”
Sikorsky will conduct its X2 Raider aircraft development program utilizing military standards. The company expects to conduct its first major program milestone — a preliminary design review — in 2011. First flight, projected in four years, could depend in part on the pace of development and customer need.
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Wow - gutsy indeed!
The Advancing Blade Concept is a technology that has come of its time.
I'll be following X2 Raider / S-97 story.
Shawn, i'm looking forward to next issue of Vertical.
The Advancing Blade Concept is a technology that has come of its time.
I'll be following X2 Raider / S-97 story.
Shawn, i'm looking forward to next issue of Vertical.
For the armed reconnaissance mission, the X2 Raider helicopter will have space aft of the two-pilot cockpit for armament and auxiliary fuel. In an assault configuration, the cabin affords space to accommodate up to six troops.
Sorry, I'll get off my soap box now ...
Finally some video
Was reading the register's latest article, some good captions and found there was a youtube video.
-- IFMU
-- IFMU