JOAN CARTAN-HANSEN, HOST: Humans have long wanted to fly, but birds, insects and bats are the only animals that actually can fly.

So for humans to fly, we need a little help.

And we started by trying to figure out how other flying creatures do it.

[MUSIC] CARTAN-HANSEN: Birds can fly because their bones are mostly hollow, air filled tubes, and they have very strong muscles.

Their bodies are designed to fly, especially their wings.

So when humans first tried to fly they copied the birds.

And it didn't work very well.

[MUSIC] Then on December 17, 1903, two brothers, Orville and Wilbur Wright, tried something different.

They were the first ones to actually fly using a powered aircraft.

It only flew for 12 seconds, but it opened the way to air travel for all of us.

PILOT: Good morning, William.

Are you ready to go fly?

STUDENT: Yay.

One question.

How does an airplane fly?

PILOT: Birds and airplanes have to overcome four forces of nature in order to fly.

Weight caused by gravity is overcome by lift of the wings, going through the air through the Bernoulli effect.

Drag, caused by air resistance is overcome by the engine and propeller thrusting the airplane through the air.

STUDENT: What's the Bernoulli effect?

PILOT: Let's take off and I'll show you.

As the plane takes off the wing splits the air into two streams.

The air traveling over the top of the wing flows more quickly than the air under the bottom of the wing.

This causes a difference in air pressure between the top and the bottom.

Because the pressure is greater below the wing than above the wing rises.

That's the Bernoulli effect.

STUDENT: So how do you fly a plane?

PILOT: An airplane flies in three dimensions.

Roll, pitch and yaw.

To roll the airplane you move the yoke to the right or to the left.

To pitch the airplane we pull the airplane back to go up and push the yoke forward to go down.

To yaw the aircraft we use the rudder pedals, pushing the left pedal to yaw left, pushing the right pedals to yaw right.

Also, the rudder pedals control the brakes and the steering of the aircraft on the ground.

PILOT: And we let the flaps down.

You want to try it?

STUDENT: Okay, sure.

PILOT: Go ahead.

Go ahead, make it do something.

STUDENT: Wheeee!

CARTAN-HANSEN: If you want to learn more about flight, check out the Science Trek website.

You'll find it at ScienceTrek.org.

[MUSIC] ANNOUNCER: Presentation of Science Trek on Idaho Public Television is made possible through the generous support of the Laura Moore Cunningham Foundation, committed to fulfilling the Moore and Bettis family legacy of building the great state of Idaho.

By the Idaho National Laboratory, mentoring talent and finding solutions for energy and security challenges, by the Friends of Idaho Public Television and the Corporation for Public Broadcasting.