Page 46 - @ccess 2 Reader´s Book

A WELL-OILED MACHINE

As a result, there is less air pressure on top of the wing; this
causes suction and makes the wing move up.

A helicopter's rotor blades are wings and create lift. An
airplane must fly fast to move enough air over its wings to
provide lift. A helicopter moves air over its rotor by spinning
its blades.

What Can A Helicopter Do?

A helicopter's rotors allow it to do things an airplane cannot.
Unlike an airplane, a helicopter does not have to move
quickly through the air to have lift.

That fact means it can move straight up or down. Most
airplanes cannot do this.
hover
A helicopter can take off or land without a runway. Glossary on
page 92
It can turn in the air in ways airplanes cannot.

Unlike an airplane, a helicopter can fly backwards or
sideways. It also can hover in one spot in the air without
moving. That makes helicopters ideal for things an airplane
cannot do.

For example,
a helicopter
can pick
someone with
a medical
problem up
where there is
no runway. It
can then land
in a small area
on top of
a hospital.

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R e ader's Book 45
Reader's Book