how many more rotations does a tail rotorblade do ,ore than the main rotorblade?

Answer 1

On a conventional helicopter, that is, one with a single main rotor and one conventional anti-torque main rotor (as opposed to fenestron and NOTAR designs), the tail rotor and the main rotor are connected to each other with a system of driveshafts and gearboxes to the engine. Therefore, the RPM of the main rotor and tail rotor are directly proportional to each other, IE, the ratio is fixed for a particular model of helicopter. The power output of the tail rotor is contolled by the pilot adjusting the angle of attack with the tail rotor pedals (foot pedals) and not by changing the RPM.

Of course, each helicopter design is different, but the ratio of tail rotor RPM to main rotor RPM varies from about 7:1 to 15:1. So the answer to your question is the tail rotor will turn 7 to 15 times for every revolution of the main rotor.

The main rotor RPM on most common light to medium helicopters (2000 to 12,000 lb GW such as Bell 206, 205, 407, Astar 350, EC 120, Agusta 109, and MD 500) is 270 to 450 RPM and tail rotors turn at 1500 to 4000 RPM. The pilot's cockpit indication for rotor RPM is usually called NR and is calibrated in percent and not RPM. In normal powered flight, both of the rotors would spin at a constant 100% NR, the optimum performance speed calculated by the design engineers. Of course, the diameter of the rotor is inversely proportional to the rotor RPM, as strange things begin to happen as the blade tips approach the speed of sound!

In a zero-wind hover, the tail rotor consumes about 17% ot total engine power output.

Answer 2

A few corrections to some answers that have been left so as to prevent confusion:
The cyclic (The stick between the pilots legs) is used for primary directional flight, including hovering, turns, forward, sideways, and backward flight.
The collective ( on the pilots left side that looks like an "emergency brake") is used to change the pitch of the main rotor blades which provide more or less lift. Also on this lever is a twist grip where on a piston powered helo controls the engine power, rpm, manifold pressure... and on a turbine the FADEC system controls that but you must turn the throttle to your selected power setting.
The tail rotor is controlled by the foot pedals and this does not increase or decrease the speed of the tail rotor, rather it changes the pitch or bite of the blades to continue to counteract the torque of main rotor

As far as your question, they vary based on the helicopter and its rotor system, and gear ratio in the transmission/ transfer case. Thanks to all the brilliant people who mentioned the NOTAR system, im sure your question intended that specifically... since their is no tail rotor and your question involved a tail rotor answer

Answer 3

The ratio depends upon the torque and power required for each helicopter, The link I provide here tells you a little about the ratio required for this particular model.
The tail rotor rpm is fixed to the main rotor via a gear box and to rotate the helicopter the pitch of the blades are changed to increase or decrease the thrust.
It takes skill and practise to fly a helicopter as the pilot anticipates the torque action as power is applied. Many new models have computer assisted controls to alleviate the fatigue associated with flying a helicopter.
The tail rotor makes more rotations than the main one.
http://www.helis.com/howflies/tailrot.php

Answer 4

There is no fixed ratio.
To answer this question it is important to understand what the tail rotor is for.
The main rotor of a helicopter provides lift, however Newton’s third law (any action results in an equal and opposite reaction) means that when the aircraft takes off, the airframe reacts to the action of the main rotor and spins in the opposite direction. The tail rotor is located at the extremities of the aircraft and its function is to counteract the airframes reaction to the rotation of the main rotor.
So the main rotor provides lift, and the tail rotor provides direction. If you want to change from a heading of due north to west, you would INCREASE the throttle on the tail rotor until you reach your heading. If you wanted to change from a heading of due north to a heading of due east you would DECREASE the throttle on the tail rotor until you reach your heading.
The collective, which is the big stick between a pilots leg is a simple forward/back/left/ right mainly used in hover flight. The main control is the twin throttles to the left of the pilot (looks like a hand break) up and down for the main rotor, twist grip for the tail rotor. Its the problem of juggling these twin throttles with one hand that make helicopters so difficult to fly.
A last point, tail rotor failure is catastrophic for helicopters, if this happens in flight there is nothing a pilot can do. Some manufacturers have tried to address this by collecting the downdraft of the main rotor and diverting this to where the tail rotor use to be and use the power of the feed air to act in the same way as a tail rotor.

Answer 5

this is dependant of the flight characteristics of the aircraft and the toque created by the main rotor and rotor head all so the all up weight of the aircraft and the gearing in the main rotor gearbox ,tail rotor gearbox , and any intermediate gearboxes fitted so the ratio is different in each aircraft type or mark and can change from aircraft to aircraft of the same type
an aircraft engineer

Answer 6

OK, seems ligit. Some are varible, most are a fixed ratio, and in the case of a hughes "notar", the answer is zero, "no tail rotor" and twin counter rotating ships, ??? get on line, and go to helifun.com, or just start with helicopters, rotorcraft, try Enstrom inc . The question is best answered, I think ,,by them,, If you wish to know how the counter torque is produced ? by single rotor. ...elsewise I myself just hang a pair of ladies pantyhose on the windsheild, and if the are spinning and screaming, you left the lady in them,,,<<

Answer 7

I always thought it was a fixed ratio, determined by gearbox of the particular aircraft.

Answer 8

Way more than 153.

I stopped counting after that.

Answer 9

The ratio is independant

Answer 10

some have the same on both ends