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The Boeing X-50A Dragonfly, formerly known as the Canard Rotor/Wing Demonstrator, was a VTOL rotor wing experimental unmanned aerial vehicle that was developed by Boeing and DARPA to demonstrate the principle that a helicopter's rotor could be stopped in flight and act as a fixed wing, enabling it to transition between fixed-wing and rotary-wing flight.
In the Bell design, Bell Model 301, the whole wingtip pod rotated between horizontal and vertical, with the engine and rotor assembly fixed together within the pod. This simplified the power transmission, but it had more complicated requirements for the engine design and was probably slightly heavier than the Boeing proposal.
The stopped rotor type has a separate system for forward thrust. It takes off like a helicopter but for forward flight the rotor stops and acts as a fixed wing. The gyrocopter is similar except that the rotor continues to spin and to generate a significant amount of lift, and so is classed as a rotorcraft and not a convertiplane.
A rotor wing aircraft has been attempted but is not in wide use. The Boeing X-50 Dragonfly had a two-bladed rotor driven by the engine for takeoff. In horizontal flight the rotor stopped to act like a wing. Fixed canard and tail surfaces provided lift during transition, and also stability and control in forward flight. Both examples of this ...
A tiltrotor is an aircraft that generates lift and propulsion by way of one or more powered rotors (sometimes called proprotors) mounted on rotating shafts or nacelles usually at the ends of a fixed wing. Almost all tiltrotors use a transverse rotor design, with a few exceptions that use other multirotor layouts.
A short input (in control systems terminology an impulse) in pitch (generally via the elevator in a standard configuration fixed-wing aircraft) will generally lead to overshoots about the trimmed condition. The transition is characterized by a damped simple harmonic motion about the new trim. There is very little change in the trajectory over ...
The various types of such rotor wings may be classified according to the axis of the rotor. Types include: [1] [2] Vertical-axis. Conventional rotary wings as used by modern rotorcraft. Spanwise horizontal-axis. Wing rotor: an airfoil-section horizontal-axis rotor which creates the primary lift. Magnus rotor: a rotor which creates lift via the ...
The XV-3 returned to the Ames wind tunnel in October 1958 to collect more data before it could be flown again. As a result of the wind tunnel testing, the rotor diameter was reduced, wing structure was increased and strengthened, and the rotor controls were stiffened. The XV-3 resumed flight testing at Bell's facility on 12 December 1958.