What is the tail rotor in a helicopter?
The tail rotor is a smaller rotor mounted vertically or near-vertically at the tail of a traditional single-rotor helicopter, where it rotates to generate a propeller-like horizontal thrust in the same direction as the main rotor’s rotation. NOTAR. NOTAR (no tail rotor) is a helicopter system which avoids the use of a tail rotor. It was developed by McDonnell Douglas Helicopter Systems (through their acquisition of Hughes Helicopters).
Why do tail rotors fail?
In contrast, a tail rotor failure involves a significant mechanical breakdown resulting in a total loss of anti-torque. This could be due to the drive shaft breaking, the tail rotor flying off the aircraft, or the tail boom detaching. These failures result in a complete loss of tail rotor functionality. Another example a main rotor-tail collisions, was a EC120 that cut off its own tail during a hard landing caused by autorotation practice. Helicopters can be vulnerable to a tail boom striking its surroundings, especially when near the ground in unfamiliar landing locations.
Can you auto rotate without a tail rotor?
The most common reason for autorotation is an engine malfunction or failure, but autorotation can also be performed in the event of a complete tail rotor failure, or following loss of tail-rotor effectiveness, since there is virtually no torque produced in an autorotation. An autorotation is the ability for a helicopter to land when the engine fails, using only airflow and inertia to keep the blades rotating during descent. An autorotation is a controlled maneuver that requires extreme precision, quick reactions, and has very little room for error.If you loose the tail rotor while landing and you are well below 60k airspeed and close to the ground, you then enter autorotation. Once you remove pitch and go to flight idle on the throttle the aircraft slows or even stops spinning.
Why is the tail rotor so important?
Not only does the tail rotor counteract torque, but its strategic placement also provides additional thrust in the same direction as the main rotor. This careful balancing act contributes to the overall stability of the helicopter. A tandem rotor helicopter has two main rotor systems and no tail rotor. Usually the rear rotor is mounted at a higher position than the front rotor, and the two are designed to avoid the blades colliding, should they flex into the other rotor’s pathway.