Turning heads at Le Bourget whenever it takes to the skies is Kamov’s Ka-52 helicopter. Its co-axial rotor blades and comprehensive weapons suite mark it out from the herd and, amazingly for a helicopter, it even has ejection seats. With the Ka-52 now in Russian army service and being touted for export, the design bureau is busy working on a maritime version for the Russian navy.
Researchers at the German Aerospace Center (DLR) in Göttingen may have discovered a way to make helicopters more maneuverable, by reducing the dynamic load on the rotor head control rods.
During rapid forward flight or maneuvering, airflow stalls on the main rotor blade as it retreats (moves backwards), giving rise to a “dynamic stall” and subjecting the rotor head control rods to formidable dynamic loads.
Van Horn Aviation (VHA) of Tempe, Ariz., wants to put more life into legacy helicopters by developing products that increase performance and lower direct operating costs by focusing on composite main and tail-rotor blades. At Heli-Expo’13, VHA is showing five examples of its work, all with different stories: tail-rotor blades for the Bell 206, UH-1 and 212/214; and main rotor blades for the MD Helicopters MD530F and Bell 206B.
Three contenders for the U.S. Army’s as-yet-undefined armed aerial scout (AAS) requirement–Bell Helicopter, Boeing and EADS North America–have just completed a series of flight demonstrations for Army evaluators who are studying alternatives to the aging OH-58D Kiowa Warrior for manned reconnaissance. They reported the results at the Association of the U.S.
Russian Helicopters, the company that parents Russia’s two helicopter design bureaus and five helicopter-manufacturing plants, is moving forward with a new-generation helicopter that is intended to replace the hugely successful Mil Mi-8/17 series. The new project, dubbed Rachel (Russian advanced commercial helicopter), clearly has many military applications.
Composite Technology, a Sikorsky Aerospace Services company based at Dallas/Fort Worth Airport, has opened a $15 million structure to dynamically balance helicopter main rotor blades. It can test main rotor blades that rotate either clockwise or counterclockwise, and its two 3,000-shp, variable-frequency drive motors make it suitable for light to heavy helicopters. A test involves three blades: a precision-balanced master blade and two test blades. One blade can weigh up to 500 pounds.
The fact that Sikorsky’s experimental X2 is a compound helicopter will not exclude it from setting an official helicopter speed record, according to Marcel Meyer, executive officer of records for the Fédération Aéronautique Internationale, the world aviation record sanctioning body.
Sikorsky Aircraft announced the X2 project just over five years ago at the 2005 Paris Air Show. Now the one and only example of what the helicopter maker calls a “technology demonstrator” is poised to break the record as the world’s fastest rotorcraft as it works its way toward a target speed of 250 knots and further proof of concept.
Sikorsky Aircraft’s X2 technology demonstrator achieved a forward speed of 181 knots on a test flight today at the Sikorsky Development Flight Center in West Palm Beach, Fla. The contra-rotating coaxial rotor prototype is designed to demonstrate that a helicopter can cruise at up to 250 knots while retaining excellent low-speed handling and efficient hovering characteristics, as well as a seamless and simple transition to high speed.
Sikorsky’s X2 compound helicopter reached another milestone last month by completing two test flights that included full engagement of the high-speed tail propulsor for the first time. In one hour of testing conducted during the two flights, the aircraft flew at speeds up to 52 knots in one test and 42 knots with the propeller providing forward thrust in the second flight.
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