User:BillCJ/Sandbox/Sikorsky X2
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- This is a sandbox for the updated Sikorsky X2 article.
| Sikorsky X2 | |
|---|---|
 Concept of an attack variant X2 aircraft |
|
| Type | Experimental helicopter |
| Manufacturer | Sikorsky Aircraft/Schweizer Aircraft |
| Maiden flight | Projected for late-2007/early-2008[1] |
The Sikorsky X2 is an experimental compound co-axial helicopter under development by Sikorsky.
Contents |
[edit] Development
[edit] Design
[edit] Sikorsky X2
Sikorsky will also incorporate decades of company research and development into X2 Technology helicopters, including: the XH-59A Advancing Blade Concept Demonstrator which showed high speed was possible with a coaxial helicopter and auxiliary propulsion, the Cypher UAV which expanded company knowledge of the unique aspects of flight control laws in a fly by wire aircraft that employed coaxial rotors and the RAH-66 Comanche, which developed expertise in composite rotors and advanced transmission design.[2]
[edit] Text 1
Sikorsky Aircraft today announced 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 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.
Sikorsky plans to build and fly its X2 Technology demonstrator helicopter at its Schweizer Aircraft subsidiary by the end of 2006. Preliminary design work for the demonstrator is finished and parts fabrication for the aircraft has commenced.
X2 Technology refers to a suite of technologies Sikorsky will apply to achieve new levels of speed and performance in coaxial helicopters. Coaxial helicopters feature two counter-rotating rotors on the same vertical axis.
The announcement came at the American Helicopter Society International's annual technical forum in Grapevine, Texas, where Sikorsky unveiled new scale models of X2 Technology helicopter concepts in various weight classes and configurations.
"We initiated X2 Technology convinced that the most productive and flexible helicopter is a helicopter which is capable of a significant increase in speed," said Sikorsky President Stephen Finger. "Customers are demanding greater speed but without sacrificing any of the unique capabilities that make helicopters the ideal platform for countless civil and military missions."
X2 Technology aircraft will hover, land vertically, maneuver at low speeds, and transition seamlessly from hover to forward flight like a helicopter. In a high speed configuration, one or more 'pusher props' are part of an integrated auxiliary propulsion system to enable high speed with no need to physically reconfigure the aircraft in flight.
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.
Previous attempts to develop faster helicopters have resulted in degraded hover performance. Likewise, attempts at fixed wing or hybrid vertical lift aircraft have resulted in aircraft with less hover capability than helicopters.
Sikorsky selected the term X2 Technology in order to: describe a class of helicopters with a coaxial design and to describe the multiplying effects (2X, or times 2) of applying a suite of modern technologies to coaxial helicopters. These technologies include new rotor blade designs, advanced flight control laws, transmissions with greater horsepower to weight performance and the ability to seamlessly transfer power from the main rotor to the aft propulser, and active vibration control.
Sikorsky will also incorporate decades of company research and development into X2 Technology helicopters, including: the XH-59A Advancing Blade Concept Demonstrator which showed high speed was possible with a coaxial helicopter and auxiliary propulsion, the Cypher UAV which expanded company knowledge of the unique aspects of flight control laws in a fly by wire aircraft that employed coaxial rotors and the RAH-66 COMANCHE, which developed expertise in composite rotors and advanced transmission design.
[edit] Text 2
Sikorsky's X2 helicopter programme has a mixed R&D heritage, and could be the model for the next generation of rotorcraft designs
Along with broadening the realm of vertical lift, first flight of Sikorsky's internally funded X2 compound helicopter demonstrator in the fourth quarter this year will also spotlight what may become the best model for introducing new civil and military rotorcraft designs - do it yourself.
DIY models could become widespread in the US rotorcraft industry, with limited amounts of government funding available for research and development and demonstrator vehicles that showcase transformational technologies.
Sikorsky is hoping its X2 technologies will increase helicopter cruise speeds by nearly 100kt
The US government continues to invest in the basic and applied research that helps manufacturers create breakthrough aircraft. However, the prime focus for most funding has become results-oriented incremental component or operational efficiency improvements to aid the US military on the battlefield.
Though the X2 concept is the result of much of that government-funded R&D, the demonstrator itself is 100% Sikorsky funded, and features a frugality and simplicity that reflects who is paying the bill. The aircraft is being built from numerous off-the-shelf components scavenged from near and far to keep costs low so much so that Peter Grant, Sikorsky advanced programmes manager, affectionately refers to the two-seater as a "mongrel". It uses dual rigid counter-rotating coaxial main rotors and a pusher propeller to reach cruise speeds of 250kt (462km/h), well beyond the 170kt maximum speed for conventional helicopters.
The X2 has a mixed heritage of government and industry R&D in rotor systems, propulsion, aerodynamics and controls technologies that will help it meet performance goals of high speed and "low" vibration - about the same vibration level as a traditional helicopter at its top speed of 140kt.
The X2's chief predecessor, the XH-59A advancing blade concept (ABC) helicopter, was built by Sikorsky and funded by the US Army, NASA, Sikorsky and others. Two vehicles were built and readied in two years, starting in 1971, a time when the US government funded such experimental aircraft.
The goal was to test the premise that rigid counter-rotating main rotors, where the advancing blade on each side produces lift while both retreated blades are feathered, could be used reduce drag and tip velocities to allow for cruise speeds well above the norm for helicopters. During testing from 1973 to 1977, Sikorsky pilots reached 240kt with the help of two fuel-thirsty auxiliary turbojets.
Though it was successful, the flight-test programme proved that the concept was ahead of its time because the technologies needed to solve key issues - high vibration levels, tedious mechanical control mechanisms and inefficient power management - have only recently become available.
"We believe it now makes this configuration feasible for next generation helicopter flight," says Grant.
The maturation was due in large part to government-funded research on military contracts, among them the Boeing-Sikorsky Comanche advanced light attack helicopter, cancelled by the US military in 2004, and its precursor, the Shadow programme, an S-76 with fly-by-wire (FBW) flight controls. Both provided the knowledge base for the X2's flight controls.
The means to control vibrations came partly from the military-funded UH-60M Black Hawk upgrade programme. Coaxial rotor design expertise came partly from the Cypher programme, a vertical takeoff and landing unmanned air vehicle demonstrator that Sikorsky developed under a US Marine Corps contract.
Solving specific problem areas through directed research, rather than funding whole demonstrator aircraft, continues to be the R&D focus for the US government. Its research is largely provided by the US Army and NASA for basic and applied research, and the Defence Advanced Research and Projects Agency (DARPA) for long-term, high-risk and potentially lucrative projects.
NASA's civil programme
NASA is planning to spend more than $40 million a year for the next four years on rotorcraft research as part of its fundamental aeronautics programme, which has a budget of $890 million.
"We're doing a host of fundamental research geared towards improved utility of civil helicopters," says Juan Alonso, programme director at NASA.
The research includes a programme to reduce rotor tip speed at cruise by 50% from hover to boost speed and reduce noise. NASA is also developing advanced control system design tools, creating new structures that reduce interior noise and vibration, and developing new tools to validate and assess helicopter capabilities and predict behaviour.
US Army investment
The US Army is investing approximately $100 million annually in R&D. This is split between its research labs, and aviation and missile Research, Development and Engineering Center (RDEC). It is focusing most of its funds on applied technologies. The army's primary R&D areas for rotorcraft include mission systems, power and drives, operations support and sustainment, and systems concepts and analysis.
Given the continued conflict in Afghanistan and Iraq, the army is naturally placing a premium on R&D that can lower the operating costs and improve the performance and safety of its helicopters. Projects within RDEC include efforts to reduce blade erosion from sand and preventing brown-out accidents through new cockpit technologies, a project the army is working on with DARPA.
The RDEC is involved in longer term projects as well, including an individual blade control (IBC) programme with Sikorsky to boost future helicopter performance, and decrease noise and vibration. Testing of a full size UH-60 blade with IBC will begin in August at the National Full-Scale Aerodynamics Complex (NFAC) at NASA's Ames Research Centre, a windtunnel facility the army and air force now operate after NASA reduced its testing infrastructure in 2002.
When the IBC testing is finished in the autumn, the army will begin experimenting with a Boeing-built "smart" rotor that uses active flaps on the blade to control vibration and noise, says Barry Lakinsmith, acting director of the RDEC's Aeroflightdynamics directorate. Though progress is being made, Lakinsmith says active rotor control research in the USA lags behind that being done abroad.
"Europe's being more aggressive on full scale active rotors. It's been difficult for us to match that given the war fight," he says.
At the US Army Research Laboratory (ARL), research is more open-ended, and can be applied to helicopters as well as ground vehicles or missiles. The big driver within ARL's vehicle technology directorate (VTD) is the Joint Heavy Lift (JHL) programme, says Mark Nixon, VTD director.
JHL, on which the military recently completed a study phase by four vendors, including Sikorsky, calls for a range of vehicles that can lift as much as 26t of Future Combat System equipment, in some cases at high speeds.
Nixon's team of 80 employees working at two NASA centres has been focusing on the ultra lightweight but protective composite structures that such an aircraft would need to provide safe travel for troops as well as increased performance. The army says it might fund a demonstrator version of the JHL in the 2015 timeframe.
Rotorcraft industry advocates have said the R&D needed to realise the development of the JHL is underfunded by about a factor of 10. Most vocal has been Rhett Flater, executive director of the American Helicopter Society, who says a sustained investment of $2 billion a year for the next five to seven years is needed for basic research.
Nixon does not necessarily agree. "I can't say we're so under-funded we just won't get there," he says, noting that the required R&D will depend on the aircraft the military chooses. An entrant like Bell's quad tiltrotor JHL candidate, for example, should not require as much research as other candidates as much of the R&D work has already been accomplished on the V-22 Osprey programme, he says.
X2 joint heavylift
Many key foundation technologies for Sikorsky's JHL entrant, a much larger version of the X2, will be tested when the X2 demonstrator takes flight later this year. Included are active vibration control centralised around the transmission, a method designed to "short circuit vibrations at their origin", says Grant. Sikorsky currently uses distributed active vibration damping systems for its production helicopters.
Once first flight is completed, Grant says his goal will be to get to high speed flight as quickly as possible. The company plans four phases of flight tests, beginning with hover and low-speed work later this year, followed by phases 2 to 4 throughout next year.
For Sikorsky, the benefits of DIY would appear to outweigh the financial risks of going it alone.
"Early on, we wanted to do this independently," says Grant. "It's best for allowing it to proceed that much more quickly."
There's another advantage to 100% internal funding: "If it's important for Sikorsky's future, we want to keep it within the company," adds Grant.
[edit] Text 3
On 01 June 2005 Sikorsky Aircraft announced 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.
Sikorsky plans to build and fly its X2 Technology demonstrator helicopter at its Schweizer Aircraft subsidiary by the end of 2006. Preliminary design work for the demonstrator is finished and parts fabrication for the aircraft has commenced.
X2 Technology refers to a suite of technologies Sikorsky will apply to achieve new levels of speed and performance in coaxial helicopters. Coaxial helicopters feature two counter-rotating rotors on the same vertical axis.
The announcement came at the American Helicopter Society International's annual technical forum in Grapevine, Texas, where Sikorsky unveiled new scale models of X2 Technology helicopter concepts in various weight classes and configurations.
"We initiated X2 Technology convinced that the most productive and flexible helicopter is a helicopter which is capable of a significant increase in speed," said Sikorsky President Stephen Finger. "Customers are demanding greater speed but without sacrificing any of the unique capabilities that make helicopters the ideal platform for countless civil and military missions."
X2 Technology aircraft will hover, land vertically, maneuver at low speeds, and transition seamlessly from hover to forward flight like a helicopter. In a high speed configuration, one or more 'pusher props' are part of an integrated auxiliary propulsion system to enable high speed with no need to physically reconfigure the aircraft in flight.
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.
Previous attempts to develop faster helicopters have resulted in degraded hover performance. Likewise, attempts at fixed wing or hybrid vertical lift aircraft have resulted in aircraft with less hover capability than helicopters.
X2 Technology refers to a suite of technologies Sikorsky will apply to achieve new levels of performance in coaxial helicopters. The X2 Technology Demonstrator is funded by Sikorsky Aircraft with development taking place in collaboration with its Schweizer Aircraft subsidiary. X2 Technology aircraft will hover, land vertically, maneuver at low speeds, and transition seamlessly from hover to forward flight like a helicopter. In a high-speed configuration, one or more 'pusher props' are part of an integrated auxiliary propulsion system to enable high speed with no need to physically reconfigure the aircraft in flight.
Sikorsky selected the term X2 Technology in order to: describe a class of helicopters with a coaxial design and to describe the multiplying effects (2X, or times 2) of applying a suite of modern technologies to coaxial helicopters. These technologies include new rotor blade designs, advanced flight control laws, transmissions with greater horsepower to weight performance and the ability to seamlessly transfer power from the main rotor to the aft propulser, and active vibration control.
Sikorsky will also incorporate decades of company research and development into X2 Technology helicopters, including: the XH-59A Advancing Blade Concept Demonstrator which showed high speed was possible with a coaxial helicopter and auxiliary propulsion, the Cypher UAV which expanded company knowledge of the unique aspects of flight control laws in a fly by wire aircraft that employed coaxial rotors and the RAH-66 COMANCHE, which developed expertise in composite rotors and advanced transmission design.
On 20 September 2005 Sikorsky Aircraft was awarded two US government contracts to perform conceptual, preliminary design for two X2 Technology(TM) heavy-lift coaxial rotorcraft. The Concept Design and Analysis (CDA) awards from the U.S. Army's Applied Aviation Technology Directorate (AATD) are in direct support of evaluating joint requirements and Joint Heavy Lift (JHL) rotorcraft for the armed forces.
Sikorsky's efforts will focus on applying coaxial rotor X2 Technology to a super heavy-lift coaxial rotor crane that can cruise at 165 knots and a high- speed super heavy lift configuration capable of cruising at 245 knots.
AATD describes the CDA activity as defining the "art of the possible, the science of the probable and the design of the affordable" JHL vertical take- off and landing rotorcraft that enables future joint concepts of operations. The CDA will set the technical foundation for joint requirement analysis leading to design concept and performance projections that can reach Technology Readiness Level 6 by 2012.
The AATD contracts call for the conceptual and preliminary design of a baseline aircraft with a 250 nm radius along with eight variations to identify the impact of changes in payload, range, environmental conditions, and shipboard compatibility on aircraft size, performance, operational suitability, cost, schedule, and development risk.
[edit] Text 4
Sikorsky is readying its X2 compound helicopter demonstrator for first flight in late 2007 or early 2008, the U.S. manufacturer announced here at the Paris Air Show. The hybrid design, which looks like a helicopter with two contrarotating coaxial main rotors and one tail propulsor, already had its fly-by-wire system tested in a small Schweizer 333 helicopter. The actual X2 has undergone engine and drive train ground tests.
According to Sikorsky, X2 technology should yield aircraft that retain helicopter capabilities while flying faster and longer. The manufacturer is talking about 250 knots and 500 nautical miles. To attain higher airspeeds, the aft propulsor provides forward thrust while the control system automatically slows down the main rotors to keep blade tips subsonic. Compared to a tiltrotor, the X2 will fly slower but does not need an in-flight reconfiguration.
Hi-tech Sikorsky emphasized that the demonstrator features several advanced technologies. For example, its main rotor blade provides more lift but without additional drag. Similarly, the rotor hub has been designed to have lower drag than other helicopters with contrarotating main rotor systems. An integrated propulsion system controls the way the main rotor and the propulsor share power. Finally, the X2 has active vibration control.
Here at the show, Sergei Sikorsky–Igor’s son–is presenting “Recollections of a pioneer” several times this week at the UTC/Sikorsky chalet. It includes a number of glimpses of the company founder’s career. Igor built the first four-engine air transport while working in Czarist Russia and then a series of flying boats after coming to the U.S. As a young man, in Kiev, he had tried to build a helicopter and failed. The first presentation took place on Monday, the second is planned for today at 2 p.m. and the final one is scheduled for Wednesday at 11 a.m.
[edit] Specifications
This aircraft article is missing some (or all) of its specifications. If you have a source, you can help Wikipedia by adding them.Data from Flug-Revue[4] NOTE: No other specifications have been released by Sikorsky.
General characteristics
- Crew: 2
- Length: ft in (m)
- Rotor diameter: ft in (m)
- Height: ft in (m)
- Disc area: ft² (m²)
- Empty weight: lb (kg)
- Loaded weight: lb (kg)
- Useful load: lb (kg)
- Max takeoff weight: lb (3600 kg)
- Powerplant: 2× LHTEC T800-LHT-801 turboshaft, 1300-1800 shp[5] (1000-1340 kW) each
- Propellers: 1 six-bladed pusher-type propeller
- *Rotor: 2 four-bladed co-axial
Performance
- Never exceed speed: knots (mph, km/h)
- Maximum speed: knots (mph, km/h)
- Cruise speed: 250 knots (mph, 460 km/h)
- Stall speed: knots (mph, km/h)
- Range: nm (mi, 1300 km)
- Service ceiling ft (m)
- Rate of climb: ft/min (m/s)
- Disc loading: lb/ft² (kg/m²)
- Power/mass: hp/lb (W/kg)
[edit] References
- ^ a b Thierry Dubois (2007-6-19). Sikorsky X2 nears flight-testing. AIN Online. Retrieved on 2007-6-25.
- ^ http://www.sikorsky.com/details/0,3036,CLI1_DIV69_ETI2088,00.html
- ^ XH-59A Advancing Blade Concept (ABC) / S-69. Retrieved on 2007-6-22.
- ^ Sikorsky X2. Retrieved on 2007-6-25.
- ^ RR Model 250 Applications
[edit] External links
- Sikorsky X2
- XH-59A Advancing Blade Concept (ABC)/S-69
- "X2 marks the spot for radical rotor designs" FlightGlobal
- Flug-Revue X2 page
[edit] See also
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Related development
Comparable aircraft
Related lists
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Category:Military helicopters Category:VTOL aircraft Category:U.S. experimental aircraft 1970-1979
