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The Helicopter
An Impressive Flying Machine

According to Joakims narration on the Synergy video one important inspration source of Covenants song "Helicopter" was an experience during his childhood: Together with his father little Joakim took a helicopter ride above his hometown and the flight permitted a completly new point of view to him. Obviously that experience was quite formative and he found enough inspration in it to create a song out of it 20 years later. But what made that little adventure possible? In other words what makes the helicopter fly after all?


Although the basic principle is known since the 10th century, its concrete usefulness has not been discovered until 1493, as Leonardo Da Vinci draw some drafts of aircrafts which shall fly by the power of a rotor system. The term "Helicopter" also has its origin in this period of time. It is mainly based on the Greek word for spiral (helix, helikos). Unfortunately at that time it wasn't technically possible to generate enough energy for a capable engine and so the firtst completely operational helicopter was not introduced before 1936.

The most important part of every helicopter is its main rotor making the lift-off possible. The so called rotor blades have a special form and they get slightly tilted. If the rotor rotates, the air above the rotor blades streams faster than below them. So a pull builds up upside the rotor and a pressure builds up under it. This pressure difference creates an ascending force wich enables the helicopter to take off.

At the rear of most helicopters there is an additional rotor called "tail rotor". Because of the rotation of the main rotor the helicopter would normaly also spin around. The tail rotor compensates that and helps to keep the helicopter on course.

To move the flight mashine in a particular direction a complicated technology is requiered. At this the angles of the rotor blades are modified depending on their current position in the rotor circuit: To move the helicopter forward, the blade wich is currently near to the rear of the helicopter is angled to a more tilted position than the blade near the front of the chopper. Thus the ascending force at the rear gets stronger and the helicopter gets pushed forward (picture).

Unlike airplanes the helicopters have the advantage to take off and land vertically without the need for runways. For this reason, helicopters are often used to operate in congested or isolated areas. The helicopter can also be navigated very precise. It can even hover on one position and it can not only fly forwards but also backwards and sidewards.



Image source: classicaviation.net
Information source: swissheli.ch, wikipedia.de, br-online.de