摘要 |
Rotorcraft wings disposed between tilt-rotor nacelles have particularly high aspect ratios for tilt-rotor rotorcraft, including for example at least 6, 7, 8, or higher. The increase in wing span and aspect ratio is possible because of the use of rigid and semi-rigid rotors, and/or higher modulus of elasticity materials allows increases the stiffness of the wings to the level required for avoiding whirl flutter. Tilt-rotor aircraft having high aspect ratio wings can advantageously further include a controller that provides reduced RPM in a forward flight relative to hover, and/or a controller that provides variable speed, (a so-called “Optimum Speed Tilt Rotor”) as set forth in U.S. Pat. No. 6,641,365 to Karem (November 2003).
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