Mit dem X2-Technologiedemonstrator will Sikorsky die Möglichkeiten für Helikopter mit Koaxialrotoren testen, die bis zu 450 km/h schnell sein sollen.
Coaxial high speed helicopter demonstrator (Versuchshubschrauber für hohe Geschwindigkeiten mit Koaxialrotoren)
Sikorsky Aircraft Corporation
6900 Main Street
Stratford, Connecticut 06497-9129
General (Allgemeine Angaben)
Crew (Besatzung): 2
Power plant (Antrieb): 1 x LHTEC T800 turboshaft, driving both the coaxial rotor and the six-bladed pusher propeller
Power (Leistung): 1080 kW (1450 shp)
No details available
Take-off weight (Startmasse): about 2405 kg
Max. speed (Höchstgeschwindigkeit): about 490 km/h (265 kts)
Max. cruise speed (max. Reisegeschwindigkeit): 460 km/h (250 kts) at about 80 per cent power
Range (Reichweite): 1300 km
No details available. The programme is fully funded by Sikorsky itself.
None. This is just a technology demonstrator
The X2 technology demonstrator is a new coaxial rotor design (counter-rotating rotors) that aims to retain the good hover performance of a helicopter while offering cruise speeds up to 460 km/h (250 kts). The X2 Technology aircraft can hover, land vertically, maneuver at low speeds, and transition seamlessly from hover to forward flight like a helicopter. In a high speed configuration, a 'pusher prop' is part of an integrated auxiliary propulsion system to enable high speed with no need to physically reconfigure the aircraft in flight.
Technologies to be used in the X2 design include:
- new, extremely rigid composite rotor blades with high lift-to-drag ratio, mounted on a compact hub with special fairing to reduce drag. It is controlled to run at 80 per cent rpm in cruise mode to prevent the blades from entering the supersonic regime
- fly-by-wire flight control system with advanced control laws (triple redundant with no mechanical backup)
- transmissions with greater horsepower to weight performance and the ability to seamlessly transfer power from the main rotor to the aft propulsor
- integrated auxiliary propulsion system. The propeller in the rear of the aircraft can get as much as 900 shp during cruise.
- active vibration control.
Key suppliers for the X2 Technology Demonstrator are:
- Aero Composites: six-blade pusher propeller
- Chelton Flight Systems : cockpit displays
- Eagle Aviation Technologies: main rotor blade manufacture, miscellaneous composite hardware
- Goodrich Corporation: SmartProbe(tm) air data system and engineering support
- Hamilton Sundstrand: Flight Control Computers, Active vibration control, engineering support
- Honeywell supplies the fly-by-wire control system
- LHTEC with an T800-801 engine
- Moog, Inc.: Active vibration actuation, Consignment MU/EU components, engineering support
According to Sikorsky, the X2 technology is highly scalable from UAVs to heavy lifters. Examples mentioned in company leafleats in mid 2008 were:
- UAS: 240 kts cruise to station, 4 hour plus endurance at 200 NM radius, full envelope weapons delivery as a growth capability
- high speed attack helicopter: 250 kts cruise, 275 kts dash speed. Full envelope weapons delivery, 600 km radius of action with 60 minutes on station
- commercial intermediate transport: 250 kts cruise, low seat mile-cost, 15 passengers and 2 crew, 250 NM radius
- SAR helicopter: 250 kts cruise speed, 250 NM radius of action, 76 inch wide door
- light military helicopter: 225 kts cruise to 110 NM radius with 230 kts dash speed, 2 crew and 4 soldiers, air transportable by C-130 Hercules
- light commercial helicopter: 2 crew and 4 passengers, 3200 lbs useful load, 220 kts cruise speed, 1700 NM range
In 2005, Sikorsky also mentioned the following possibilites:
- heavy lift crane helicopter with 25 ton external load
- high-speed joint heavy lift transport with 25 ton internal load
On 1 June 2005, at the American Helicopter Society International's annual technical forum in Grapevine, Texas, Sikorsky president Steve Finger 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 also showed scale models of X2 Technology helicopter concepts in various weight classes and configurations. At that time, preliminary design work was already finished and parts fabrication for the aircraft had commenced.
In September 2005, Sikorsky was awarded two US government contracts to perform conceptual, preliminary design for two X2 Technology heavy-lift coaxial rotorcraft. The Concept Design and Analysis (CDA) awards from the U.S. Army's Applied Aviation Technology Directorate (AATD) were in direct support of evaluating joint requirements and Joint Heavy Lift (JHL) rotorcraft for the armed forces. Sikorsky's efforts focus on applying coaxial rotor X2 Technology to a super heavy-lift coaxial rotor crane that can cruise at 165 knots (305 km/h) and a high- speed super heavy lift configuration capable of cruising at 245 knots (450 km/h). The AATD contracts call for the conceptual and preliminary design of a baseline aircraft with a 250 nm (460 km) 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.
On November 3, 2005 a surrogate helicopter equipped with the new X2 Technology fly-by-wire system made its first flight at Elmira, New York. The Schweizer 333 helicopter demonstrated basic capabilities of the X2 Technology fly-by-wire system during a one half hour flight. "The X2 Technology demonstrator program continues to advance on plan toward first flight before the end of 2006. The Schweizer 333 fly-by-wire flight provides just one indication of the excellent progress the team has made this year," said Carey Bond, Vice President Corporate Strategy and Advanced Programs. At that time, first flight was still targeted for the end of 2006.
By May 2006, construction of the X2 airframe was progressing at Schweizer, and the first round of rotor testing was complete.
At the Farnborough Air Show in July 2006, Sikorsky president Jeff Pino said that the X2 demonstrators forward fuselage, centre fuselage and tailcone had come together and that major system detail design had been completed. He predicted ground testing for the summer.
Ground testing of the X2 began on 3 November 2006, but without the rotor.
By January 2007, no first flight had occurred and Sikorsky was now saying that pressure to put near term programmes and production in order had led to the X2 being put on the back burner.
The X2 re-entered vehicle ground testing in November 2007, “after additional build and subsystem test progress”, according to Sikorsky.
On February 24, 2008, Sikorsky unveiled its X2 Technology Demonstrator at the George R. Brown Convention Center in Houston at Heli-Expo 2008. It was said that some 20 hours of ground runs had been achieved so far and that first flight is now close.
The initial ground test with the “blades-on” was conducted on 13 May 2008 at Horeseheads, New York, and went according to plan, Sikorsky said.
At the Farnborough Air Show in mid-July 2008, Sikorsky gave further details of the X2 programme, now saying that there were 7.5 hours of ground tests without the rotor blades and 8.5 hours with rotor blades on so far. Before first flight, a further 25 hours were needed, plus final system shakedown. The first phase of hover tests without the pusher prop was to take place at Schweizers facility (40 hours), before moving the X2 to West Palm Beach.
Sikorsky successfully completed the first flight of its X2 Technology Demonstrator on 27 August 2008, maneuvering the prototype aircraft through hover, forward flight, and a hover turn, in a test flight that lasted approximately 30 minutes. Sikorsky Chief Test Pilot Kevin Bredenbeck conducted the test flight at Sikorsky's Schweizer Aircraft Corp. rapid-prototyping facility in Horseheads, N.Y.
The second flight took place on 18 September 2008, again with Bredenbeck at the controls. Changes to to fly-by-wire system had been made in the interim, to „desensitise“ control responses.
Sikorsky conducted the first ground testing with the rotating high-speed pusher propeller on 23 January 2009 at Horseheads. The prop produced the expected amount of thrust and the drive system and oil distribution system worked well, the manufacturer said. This milestone effectively completed Phase I of the tests.
Last updated: 3 February 2009