Search results
Results from the WOW.Com Content Network
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 Magnus effect. Flettner rotor: a smooth cylindrical Magnus rotor with disc end plates.
A Bell 47 helicopter, an early example of a powered rotorcraft. A rotary-wing aircraft, rotorwing aircraft or rotorcraft is a heavier-than-air aircraft with rotary wings that spin around a vertical mast to generate lift. The assembly of several rotor blades mounted on a single mast is referred to as a rotor.
An example of the effect of rotor blade number is the UH-72 (EC145 variant); the A model had four blades, but the UH-72B was changed to five blades which reduced vibration. [24] Other blade numbers are possible, for example, the CH-53K , a large military transport helicopter has a seven blade main rotor.
Conventional rotary-wing aircraft use a set of complex mechanical gearboxes to convert the high rotation speed of gas turbines into the low speed required to drive main and tail rotors. Unlike powerplants, mechanical gearboxes cannot be duplicated (for redundancy) and have always been a major weak point in helicopter reliability.
The cyclogyro wing resembles a paddle wheel, with airfoil blades replacing the paddles. Like a helicopter, the blade pitch (angle of attack) can be adjusted either collectively all together or cyclically as they move around the rotor's axis. In normal forward flight, the blades are given a slight positive pitch at the upper and forward portions ...
a rotary wing aircraft intermediate in type, hereinafter referred to as "gyrodyne", between a rotaplane (with the rotor free for autorotation and an upward total axial flow through the rotor disc), on the one hand, and a pure helicopter (with the rotor driven, and a downward total axial flow through the rotor disc), on the other hand, that is ...
The A-7 was the first rotary-wing aircraft designed for combat, [22] armed with one 7.62×54mmR PV-1 machine ... only one example was built and it did not enter service.
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.