Making a Paper Helicopter
This shows the way air flows over the blades of a helicopter.
What you need
Download and print off the attatched PDF for your helicopter cut-out.
What to do
1. Fold A in the middle.
2. Fold B in the middle.
3. Fold C up.
4. Fold E forwards and D backwards.
5. Launch the helicopter by dropping it from a height.
The weight of our paper helicopter applies a downward force in the air, which then pushes the air back. This provides an equal and opposite upward force on the helicopter wings which slows the helicopter's fall.
The wings do not trap the air, it flows past them. This is why the helicopter continues to fall rather than hanging in the air.
As the helicopter falls, air is forced away from the wings and gets pushed towards the centre of the helicopter. The air pushes on the square area of paper (the folds D and E) in the centre of the helicopter. This happens on both wings, so both sides of the square receive the same force. The force combined with air resistance and the inward movement of the air to the centre of the helicopter makes the helicopter spin.
The helicopter circles clockwise or anticlockwise depending on which wing you fold forwards and which one you fold backwards.
To take off, a helicopter stands still and makes its 'wings' (the big overhead blades) spin, rushing through the air. The faster they spin the more lift they create. However just spinning the blades will not get the helicopter off the ground. It is only when the pilot tilts the blades at a specific angle that they put enough force on the air to get lift (the force needed for take off). The air is forced downwards and this causes the helicopter to rise. Unlike planes which are sucked up into the air because of the shape of their wings and their speeds, helicopters actually push the air down by forcing themselves up.
The pilot steers the helicopter by tilting the blades in the direction they want to go.
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