Search results
Results from the WOW.Com Content Network
The number of rotors is also important, many helicopters have two rotors in a single line, and another configuration is 4 rotors. [22] An example of two-blade rotor is the Bell 212 , and four blade version of this helicopter is the Bell 412 . [ 23 ]
The tail rotor is powered by the helicopter's main power plant, and rotates at a speed proportional to that of the main rotor. In both piston and turbine powered helicopters, the main rotor and the tail rotor are mechanically connected through a freewheeling clutch system , which allows the rotors to keep turning in the event of an engine ...
However, the rear rotor works in the aerodynamic shadow of the front rotor, which reduces its efficiency. This loss can be minimized by increasing the distance between the two rotor hubs, and by elevating one hub over the other. [4] [5] Tandem-rotor helicopters tend to have a lower disk loading than single-rotor helicopters. [6]
The Boeing Vertol CH-46 Sea Knight is a medium-lift tandem-rotor transport helicopter, furnished with a set of counter-rotating main rotors in a tandem-rotor configuration. It was typically powered by a pair of General Electric T58 turboshaft engines, which were mounted on each side of the rear rotor pedestal; power to the forward rotor was ...
Tiltrotor design combines the VTOL capability of a helicopter with the speed and range of a conventional fixed-wing aircraft. For vertical flight, the rotors are angled so the plane of rotation is horizontal, generating lift the way a normal helicopter rotor does. As the aircraft gains speed, the rotors are progressively tilted forward, with ...
Sikorsky states that the X2 has the same noise level at 200 knots that a regular helicopter has at 100 knots. Above 200 knots, the rotor speed is reduced from 446 to 360 RPM [35] [36] to keep tip speed below Mach 0.9, the rotor disc is slightly nose-up, and the lift-to-drag ratio is about twice that of a conventional helicopter. Hands-off ...
A coaxial-rotor aircraft is an aircraft whose rotors are mounted one above the other on concentric shafts, with the same axis of rotation, but turning in opposite directions (contra-rotating). This rotor configuration is a feature of helicopters produced by the Russian Kamov helicopter design bureau.
Location of flight controls in a helicopter. Helicopter flight controls are used to achieve and maintain controlled aerodynamic helicopter flight. [1] Changes to the aircraft flight control system transmit mechanically to the rotor, producing aerodynamic effects on the rotor blades that make the helicopter move in a desired way.