How Do Helicopters Fly?

They're essentially spinning wings.

So first, think about an airplane wing.

Think about the wings on an airplane.

As air flows over it, its shape creates an upward force called lift.

We've talked about lift before on the show.

Lift is what holds the aircraft up against gravity.

A helicopter's rotor blades work the same way, except instead of the whole aircraft moving forward to push air over the wings, the blades themselves spin fast enough to do the same job.

As the rotor spins, each blade, which is shaped much like a wing, pushes air downward, and the air pushes back up against the blade.

That reaction is what lifts the helicopter off the ground.

You've probably felt a milder version of this while standing near a very powerful fan.

You can feel it pushing air toward you.

A helicopter's rotor does something similar, just on an even bigger scale.

When the upward force from the rotor exceeds the helicopter's weight, it climbs into the air.

Imagine pointing one of those big box fans at the ground.

That's a lot like what a helicopter is doing to lift itself up off the ground.

If the box fan's blades were spinning fast enough that it could actually lift off the ground if you pointed it at the ground, that's- that's kind of what a helicopter is doing.