• April 1, 2011

    How does a helicopter fly



    A helicopter is one of the most manoeuvrable flying vehicles that exist today. This gives the pilot the possibility to manoeuvre the helicopter into a three-dimensional space like no airplane can do. The pilot can virtually fly the helicopter almost anywhere you can think of. However, the task is not easy. The pilot needs to be able to think in three dimensions and use both pedals; the collective control and the direction stick to maintain the helicopter flying.



    The blades on the main rotor are shaped with airfoils just like you will see it on a normal aeroplane. The shape of these airfoils is the main reason for keeping the helicopter in the air. As the rotors spin, they cut through the air and lifts the helicopter. This makes the main rotor the most important part of the helicopter. By using the collective control, the pilot can adjust the ‘pitch’, meaning that the angle of the blades change to make the helicopter go up or down.



    The tail rotor is crucial to control the helicopter. When the main rotor is spinning, the entire helicopter will try to spin as well leaving no control over the helicopter. By using the tail rotor the pilot can avoid the rotation of the helicopter and hold it in a firm and straight direction. To manage this, the pilot has two foot pedals that control the angle of the tail rotor and thereby the movement of the helicopter. By applying more or less angle on the rotor blades the pilot may turn right or left.



    An important mechanism is the ‘swash plate that is used to control is the angle of the blades. The swash plate is made from two plates where one is fixed and one is rotating. The direction stick pushes one side of the swash plate upwards or downwards to change the pitch angle of the blades unevenly. This will change the angle of the blades depending on where they are in the cyclic rotation. This gives more angle on one side of the helicopter and will make the helicopter tip. By controlling this swash plate the pilot is able to tip the helicopter to go in the direction he wants.