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The Case of the Challenging Flight

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Subido el 28 de mayo de 2007 por EducaMadrid

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NASA Sci Files video containing the following twelve segments. NASA Sci Files segment describing how engineers negotiate the natural factors that affect airplane flight. NASA Sci Files segment describing how airplane designer Burt Rutan takes projects fro

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Hey, you heard me, yeah, you come see our clubhouse and our tree. 00:00:00

We are kids on a mission to educate ourselves about the NASA vision. 00:00:19

Come explore math and science, cause that's what makes our alliance. 00:00:24

All who walk our club, we yearn to learn and want to see 00:00:29

everything that we can be, so come join us on our journey. 00:00:33

Don't you touch that dial, and welcome to the NASA White House. 00:00:38

Yeah! 00:00:46

This is Kids Science News Network, and I'm Ted Toon. 00:00:52

Aviation enthusiasts are all aflutter today with the announcement of the $10 million X Prize. 00:00:55

That's right, ladies and gentlemen, if you can design a reusable aircraft 00:01:01

capable of taking three tourists into space, the $10 million is yours. 00:01:04

Wow, I could buy a lot of air freshener with $10 million. 00:01:09

Oh, sorry, a little closer to home, the annual Extraordinary Airplane Contest 00:01:13

is set to get underway next week. 00:01:19

We have a live report from I Am Listening. 00:01:21

Ted, I'm here at the site of this year's contest. 00:01:24

Only days from now, teams from all over the area will compete to see 00:01:28

which airplane can fly the farthest. 00:01:32

The twist is that each plane must be made completely out of egg cartons. 00:01:35

We'll have to wait and see exactly how each team solves the problems of flight. 00:01:41

Can an airplane made out of egg cartons really fly? 00:01:47

Will the Treehouse Detectives place dead last again this year? 00:01:50

We may never know. Back to you, Ted. 00:01:54

Yeah, we know all about the Extraordinary Plane Competition. 00:01:57

Everyone at the competition knows us as the big losers. 00:02:00

We always come in last place every year. This is the entry from last year. 00:02:03

Looks like a winner compared to my entry from last year. 00:02:08

What did you do? 00:02:10

I just stuck a fuselage through an egg carton. 00:02:12

It doesn't even fly. 00:02:16

My grandmother says you can learn a lot from your failures. 00:02:18

Even the Wright brothers, Wilbur and Orville, had a few failures before they first took flight 00:02:21

on December 17, 1903, in Kitty Hawk, North Carolina. 00:02:26

I found these facts referenced on this flight book and that's Guadal's website. 00:02:30

Did you know that a lot of inventors entered aviation contests? 00:02:34

Like us? 00:02:37

Not exactly like us. 00:02:38

Back in 1927, Charles Lindbergh won the Ortiz Prize of $25,000 00:02:39

for being the first person to cross the Atlantic Ocean in a plane. 00:02:43

That's right. He flew from New York to Paris, France. 00:02:46

You see, without these types of contests, we might not have the advanced technology 00:02:49

or the types of airplanes that we have right now. 00:02:54

Don't forget the race to space. 00:02:57

If we hadn't competed with Russia, NASA might not have sent the first man to the moon. 00:02:59

Now that's true. 00:03:03

I think we need to do more research on the history of flight. 00:03:04

Remember what we learned in class about science is inquiry? 00:03:07

Research is important. Let's surf the Internet. 00:03:10

I'll let you in on something really neat. 00:03:13

NASA has a website on how things fly. 00:03:15

Oh, look. Here's the fun fact about the history of flight. 00:03:17

Let's click here. 00:03:21

And now, Aviation History. 00:03:24

Here's Dr. Textbook. 00:03:27

Hello! 00:03:30

Since the beginning of time, man has looked up at birds with awe and has wondered, 00:03:31

Why can't we fly? 00:03:36

Mythology gives us the story of Icarus, 00:03:40

who flew too close to the sun, melting his wings made of feathers and wax. 00:03:43

In the 15th century, Leonardo da Vinci made over 150 drawings of his ideas for a flying machine. 00:03:48

But it was George Cayley who noticed how a bird's wings kept them in the air. 00:03:55

He made a number of various gliders, testing out different wing shapes and patterns. 00:03:59

Wilbur and Orville Wright wrote letters to Octave Chanute, who was designing his own gliders, 00:04:05

and he helped them to understand the forces of flight. 00:04:09

After many trial runs with various gliders, 00:04:12

the Wright brothers made the first successful control-powered flight with a pilot on board in 1903. 00:04:15

So, as a note to all the people who made the first flight possible, 00:04:21

I will fly across this sand dune in my wings! 00:04:26

Well, not a very good idea. 00:04:40

This has been Aviation History. 00:04:47

That's so cool. It looked like the pioneers of aviation had a lot of different challenges. 00:04:52

I think we need to learn more about our challenges and try to win the Extraordinary Plane Competition. 00:04:56

But how do we do that? 00:05:00

I think we need to learn how planes fly. 00:05:02

The National Air and Space Museum will be the place to start. 00:05:04

Let's see if our parents can take us. 00:05:07

I found a research notebook so we can take plenty of notes. 00:05:09

I also found a get-up-and-go worksheet on the NASA Wi-Fi Earth website. 00:05:13

This will be just what I need to keep track of what we learn on the field trips. 00:05:17

So, let's get up and go. 00:05:21

This is so cool. 00:05:29

Look, there's the original Wright brothers' plane. 00:05:31

Look over there. There's the Spirit of St. Louis. 00:05:34

Oh, yeah. That's the plane that Charles Lindbergh flew to Paris. 00:05:37

He won $25,000. 00:05:41

Hi, can I help you? 00:05:44

We'd need to learn more about the history of flight. 00:05:46

Well, you must be the treehouse detectives. 00:05:49

We most certainly are. 00:05:51

Hi, I'm General Jack Daly, the director of the Smithsonian's National Air and Space Museum. 00:05:53

I want to welcome you here this morning. 00:05:57

Can you tell us a little more about the history of the Wright brothers' plane? 00:05:59

Sure. The Wright brothers were the first ones to solve the technical problems associated with flight. 00:06:02

Many others had tried, but these two brothers, working alone, 00:06:07

developed the fundamental principles of flight that are still in place today, 00:06:10

and they changed our lives completely. 00:06:14

We know that contests play an important part in the history of aviation. 00:06:16

Why is that? 00:06:20

Well, competition is important in life no matter what we're doing, 00:06:21

whether we're playing soccer, competing for the Olympics, or trying to build a better airplane. 00:06:24

If you want to be the number one or the best, you have to work harder. 00:06:29

The Race to Space was another competition? 00:06:33

Sure was. It was a race between the United States and the Soviet Union, 00:06:35

and each country was trying to demonstrate that they were better in space flight. 00:06:40

But what started as a competition has now turned into a partnership 00:06:44

with the United States, Russia, and other countries building an international space station. 00:06:47

We need to learn more about the four forces of flight. 00:06:51

Is there a place here where we can explore? 00:06:54

There sure is. It's called How Things Fly. 00:06:56

Kaylie, this is so neat! 00:07:08

I wonder if these controls have anything to do with lifts. 00:07:10

Use the aileron, elevator, and rudder to control roll, pitch, and yaw. 00:07:27

Hey, Bianca, I can see the four forces of flight working. 00:07:35

We need to go. 00:07:39

I'm having too much fun. 00:07:40

Guess where we went this weekend? 00:07:47

I don't know. Outer space? 00:07:48

Funny, Dr. D. We went to the National Air and Space Museum. 00:07:50

Oh, did you see the White Brothers plane? 00:07:54

Yeah, it was so cool. 00:07:55

Well, did you know that after the last flight, a gust of wind came up and sent the White Brothers flyer tumbling across the sand? 00:07:57

Is that why the Wright flyer never flew again? 00:08:03

That's right, because it was damaged. 00:08:05

Today, planes are built much differently. 00:08:07

When we went to the museum, we learned about the four forces of flight. 00:08:09

What are the four forces of flight? 00:08:12

Let's see. There's lift, that pushes a plane upward. 00:08:14

And weight, which is Earth's gravity pulling down on a plane. 00:08:17

Then thrust, which is the power to push a plane through the air. 00:08:21

Oh yeah, and drag. 00:08:24

Why do you think it's important that we must understand all four forces? 00:08:26

I'm not sure. I would guess you have to have all of them to make a plane fly. 00:08:30

Yes, they're all connected to each other. 00:08:34

For example, changing the thrust also affects the lift and the drag. 00:08:36

We must first examine them individually before we can see how they're related to each other. 00:08:40

Can we start with the force of lift? 00:08:44

Sure. What part of the plane do you think provides the lift? 00:08:47

I would say the wings. 00:08:50

That's right. The wings are designed to push air downward. 00:08:52

The air flowing over top of the wing and the air flowing underneath the wing are both bent downward. 00:08:55

These fan blades are just like a wing. 00:09:02

Look at the blades. See how they're angled? 00:09:05

Yes, why is that? 00:09:07

Well, the blades are angled upward from the direction of motion. 00:09:09

This angle allows the blades to push the air downward. 00:09:12

How do airplane wings compare to fan blades? 00:09:16

As the fan blades spin, they cut through the air like an airplane wing. 00:09:19

Take a look at this airplane that I got many years ago. 00:09:25

Notice how the wing is slanted upward with the front edge higher than the back edge. 00:09:27

Turn on the fan now and see what happens. 00:09:32

Those fan blades are pushing a lot of air. 00:09:38

How can we increase the air pushed down by the fan? 00:09:40

It could spin faster. 00:09:43

Indeed. A faster spinning fan blade is like an airplane wing flying through the air faster, pushing more air down. 00:09:45

Why does a wing need to push air down? 00:09:51

It's what provides lift. 00:09:53

I don't get it. How does pushing air down create lift? 00:09:55

Mr. Isaac Newton said, for every action there is an equal and opposite reaction. 00:10:00

It's called his third law. 00:10:05

So that means when the wing pushes the air downward, the air is pushing up on the wing? 00:10:07

Correct again. 00:10:12

Let's try an experiment. 00:10:13

Tip the fan up like this and put it on these skates. 00:10:15

Now the fan is going to push the air this way, that's the action. 00:10:19

And the air is going to push the fan the other way, that's the reaction. 00:10:23

All right. 00:10:32

Wow. 00:10:33

I bet the problem with our airplane last year was that we didn't have an angle on the wing. 00:10:34

If we don't have an angle on the wing, we can't push the air downward and get an upward lift. 00:10:39

We need to angle the wing up, and it would work better. 00:10:43

I can't believe that the air will push up on this model plane and give it lift, 00:10:46

but it's hard to believe that air can push up and give lift to something as big as those passenger jets. 00:10:50

They do weigh a lot more, but I guess their wings are a lot bigger. 00:10:56

Well, it's almost like magic, but it's real science. 00:11:00

To really understand lift, you need to visit a wind tunnel. 00:11:03

Let's contact Luther Jenkins over at NASA. 00:11:06

Wow. 00:11:12

This is really neat. 00:11:13

Have you ever seen a wind tunnel? 00:11:14

I've never been in a wind tunnel, but I've seen them on TV. 00:11:16

Well, this is one of 30 wind tunnels we have here at the NASA Langley Research Center in Hampton, Virginia. 00:11:18

We found at the National Air and Space Museum that the Wright Brothers built their own wind tunnel in 1901. 00:11:23

They collected data from that wind tunnel and put it in a successful glider. 00:11:28

That's absolutely correct. 00:11:31

What do you use wind tunnels for? 00:11:33

Well, like the Wright Brothers, we use wind tunnels to examine how the air flows over different objects, 00:11:35

like planes, cars, wings, and even tires. 00:11:39

This helps us understand how they will perform and gives us insights so that we can develop new designs. 00:11:43

Is there anything you can show me? 00:11:48

Well, Dr. D showed you how the angle of a wing actually deflects the air downwards to create lift. 00:11:50

I'm going to show you how the air flows over a wing. 00:11:55

This is a different way of looking at the concept of lift. 00:11:58

Come with me. 00:12:00

Okay. 00:12:01

What do you mean to show me how the air goes over the top of the wings? 00:12:03

We can see air? 00:12:06

No, you really can't, so we use smoke to visualize the air. 00:12:07

Can you see how the smoke particles that strike the front edge of the wing? 00:12:10

Some travel over the upper surface and some travel over the lower surface. 00:12:14

It looks like the smoke is going faster over the top of the wings. 00:12:17

You're right. 00:12:20

The curvature of the upper surface actually causes the smoke particles to speed up or travel faster over the upper surface. 00:12:21

The force applied by these faster moving particles on the upper surface is lower than the force that is applied on the lower surface by the slower moving particles. 00:12:27

The difference in forces actually creates a lift and causes the plane to stay in the sky. 00:12:35

That's weird. 00:12:40

I wonder how big airplanes stay in the air. 00:12:41

I mean, they're so large. 00:12:44

That's true. 00:12:45

They are very big, but they also have large wings, and the air has more surface area over which to travel. 00:12:46

That generates more lift and allows them to stay in the sky. 00:12:51

Why is it important to test airplane wings? 00:12:54

Well, we test airplane wings so engineers would know which ones to use for their particular design or application. 00:12:56

That saves time and money. 00:13:02

That was so cool. 00:13:04

I think it was so interesting seeing how the smoke went over the wings. 00:13:06

Well, I hope it helps. 00:13:09

I'm sure you'd do well in the contest. 00:13:10

Thanks. 00:13:11

I made a new plane for the contest. 00:13:14

By the way, if you would like to design your own plane, just click on the problem board inside the treehouse. 00:13:16

Have fun. 00:13:21

This plane looks better than last year's entry. 00:13:22

That's strange. 00:13:26

I wonder why it goes up like that. 00:13:27

We made the exact same plane last year. 00:13:28

It didn't win, but it didn't fly upwards either. 00:13:30

It looks like all the variables are the same. 00:13:33

Do you use scientific inquiry to help you figure out problems? 00:13:35

It really works. 00:13:39

Remember, when you're conducting an experiment, it's very important to keep all the variables the same. 00:13:40

Let me see your plane. 00:13:45

I want to compare it to last year's entry. 00:13:47

I have my notebook right here of the experiments we did last year. 00:13:49

The wings are still small. 00:13:52

Let's use our problem board to get organized. 00:13:54

This is actually fun and easy to use. 00:13:56

You should try it. 00:13:58

We know the airflow underneath the wing moves slower and creates a higher pressure. 00:13:59

We know that the airflow under the wing pushes the wing upward and helps provide lift. 00:14:04

And we need to know if the size of the plane's wings affects lift. 00:14:09

We need to know more about the other forces of flight, thrust, and drag. 00:14:13

Where do we need to go? 00:14:17

Maybe our friends, the Y-Files Kids Club, can help us. 00:14:18

I love talking to other club members. 00:14:22

We are one big team working together trying to solve a problem. 00:14:24

I'll email the club this question. 00:14:28

Has anyone done an experiment on how the size of the wings affects lift? 00:14:30

I would think so. 00:14:34

Just look at history. 00:14:35

The Wright Flyers' wings look a lot different from today's planes. 00:14:36

Yes, the Wright Flyers' wings were very boxy. 00:14:39

I'm receiving a message from the NASA Y-Files Kids Club. 00:14:42

Achievable Dream School in Newport News, Virginia, 00:14:46

is currently doing an experiment on the size of the wings. 00:14:49

Hi, I'm Linda Zaromski from Mr. Tyson's 6th grade class at Achievable Dream Academy in Newport News, Virginia. 00:14:57

What is the problem you're trying to solve? 00:15:03

We wanted to know if the size of the airplane's wings affected its flight. 00:15:05

What was your experiment? 00:15:10

Our teacher, Mr. Tyson, set up the test area. 00:15:11

Let's take a look at it. 00:15:15

The test area has a hinge with a 62-centimeter stick attached with a pushpin on the other end. 00:15:16

The stick should go up and down freely. 00:15:22

Here is our test fuselage. 00:15:25

We will be attaching to it different size wings that we have made. 00:15:27

Why has the propeller been removed? 00:15:32

We are going to be using a fan to create our thrust instead of the propeller. 00:15:34

However, paper clips have been added to replace the weight of the propeller so that we keep our variables the same. 00:15:39

Let's test it and see how it lifts. 00:15:46

Okay, we attached the small wing to the fuselage like this. 00:15:48

Now we turn the fan to a low speed. 00:15:52

I think we need to turn it up to medium because the wing is not lifting much. 00:15:55

Now look at it lift. 00:16:03

It is stable now so add paper clips one at a time until the plane will no longer fly. 00:16:05

Wow, it held five paper clips and each paper clip is about 1.5 grams. 00:16:12

So our total weight added was 7.5 grams. 00:16:18

We decided to do the experiment at least two more times. 00:16:22

Now we need to take an average of all the trials for each wing. 00:16:27

Remember how to get an average? 00:16:32

Just add up all the numbers and divide by the total number of numbers you added. 00:16:34

Now we are ready to test the other wing. 00:16:39

Remember, keep all the variables the same during the experiment. 00:16:42

The only variable that will change is the size of the wing. 00:16:46

Let's take a look at our data. 00:16:50

The small wing held 7.5 grams of paper clips while the larger wing held 18 grams of paper clips. 00:16:52

So that means that since the larger wing lifted the most weight, it has the best lift. 00:16:59

Newport News isn't that far away. Maybe we can test our new hypothesis. 00:17:05

Our new hypothesis is if you change the size of the wings, then it will have the best lift. 00:17:09

We're not seeing any lift here, that's for sure. 00:17:15

We need these planes to soar. That's if we want to win the competition. 00:17:17

We need my man Jackie Chan to be here. He's a human flying machine. 00:17:20

Yeah, right. What could he do? 00:17:24

He's so cool. I just saw him in a movie and he flies right through the air. 00:17:26

I bet he knows all about the force of lift. 00:17:29

That's fake. That's just a movie. 00:17:31

No way. If he was here, he would help us win that competition. 00:17:33

He's so cool. I just saw him in a movie and he flies right through the air. 00:17:36

I bet he knows all about the force of lift. 00:17:39

That's fake. That's just a movie. 00:17:41

No way. If he was here, he would help us win that competition. 00:17:43

Who's that? Is that who I think it is? 00:17:57

It's him, Jackie Chan. 00:18:00

You mean the martial arts master? 00:18:02

Nice to meet you, Mr. Chan. 00:18:14

Nice to meet you. 00:18:15

Hi. 00:18:16

Hi, hi, hi. I hear you guys need my help. 00:18:17

Uh-huh. 00:18:20

What do you do when you're faced with a challenge? 00:18:21

I just never give up. 00:18:23

Think about it before I do the stunt. 00:18:29

But I'm not going to do it today. I'll do it tomorrow. 00:18:31

Can you help us? 00:18:34

I'm going to help you to build a super-duper airplane. 00:18:35

Okay? 00:18:38

Okay. 00:18:43

Okay. 00:18:51

Wow. 00:18:56

See? 00:18:57

Do you think studying is important? 00:19:05

At 17, I get out of school. 00:19:07

Then slowly, slowly, I find out 00:19:09

education is more important than doing the punch and kicking. 00:19:11

Good luck. I know you guys will be winners. 00:19:15

Okay? Bye-bye. 00:19:17

Bye. 00:19:18

Thank you. 00:19:19

Thank you. 00:19:20

Thank you, Jackie Chan. 00:19:21

That was really him. 00:19:22

It sure was. 00:19:24

You know, I just have those connections. 00:19:25

Yeah, right? 00:19:28

So what's up? 00:19:31

Should the Treehouse Detectives change the size of their wings? 00:19:32

What should they do next? 00:19:35

How can they get more lift? 00:19:37

Tune in next time for another episode of 00:19:38

The Case of the Challenging Flights. 00:19:40

I made the wings on our plane longer. 00:19:46

Look how it flies now. 00:19:48

Wow, what a difference. 00:19:50

Watch this. 00:19:52

I'm trying out an experiment I found on a website. 00:19:53

What experiment did you find? 00:19:56

It's supposed to demonstrate Bernoulli's Principle. 00:19:57

I'm blowing air between these two balloons. 00:20:00

What happens? 00:20:02

The balloons come together. 00:20:03

I wonder what's causing it to do that. 00:20:05

I think it has something to do with airflow. 00:20:07

Remember what we learned from NASA researcher Luther Jenkins 00:20:09

that fast-moving air creates less force? 00:20:12

Air pressure changes with speed. 00:20:14

So blowing between the two balloons 00:20:16

made the air flying between them speed up. 00:20:18

This reduced the pressure in the middle of the balloons. 00:20:21

The reduced air pressure in between the balloons 00:20:23

allows the air pressure on the outside of the balloons 00:20:25

to push the balloons inward towards each other. 00:20:28

And in local news, 00:20:31

the Extraordinary Airplane Contest 00:20:32

is shaping up to be a real nail-biter this year. 00:20:34

Several teams are on the field testing their designs. 00:20:37

And we have a live report from I Am Listening. 00:20:40

I Am? 00:20:42

Ted, history has shown us that aviation science 00:20:43

often advances rapidly due to competitions and contests 00:20:46

not unlike this one. 00:20:51

Teams from all over the country are converging here 00:20:53

at Flying Ace Field 00:20:56

to see if their designs will take home the big prize. 00:20:58

One team from somewhere in Virginia 00:21:02

has constructed a full-scale jet liner 00:21:05

out of nothing but egg cartons. 00:21:08

We'll see if... 00:21:11

Ahh! 00:21:12

It looks like they've got a few bugs to work out, Ted. 00:21:14

From Flying Ace Field, 00:21:19

We learned that from the Air and Space Museum 00:21:21

in Washington, D.C. 00:21:23

I read about a modern-day aviation pioneer. 00:21:24

His name is Burt Rutan. 00:21:27

Wouldn't it be great to talk to him, 00:21:29

a guy who was involved in a real-life challenging flight? 00:21:30

Let's look on the Internet 00:21:33

to research a list of those aviation pioneers. 00:21:34

Here he is, Mr. Burt Rutan 00:21:37

from Scaled Composites in Southern California. 00:21:39

Let's dial him up. 00:21:42

Hello, Mr. Rutan. 00:21:44

You've had a lot of experience designing planes. 00:21:45

Could you please show us one of your unique designs? 00:21:48

Oh, sure. 00:21:51

I love to talk about airplanes. 00:21:52

I've designed some 28 different manned airplanes 00:21:54

and also some unmanned airplanes. 00:21:57

One of the things I love about airplanes 00:22:00

is that they're so easy to design. 00:22:02

They're so easy to build. 00:22:04

They're so easy to build. 00:22:05

They're so easy to build. 00:22:06

They're so easy to build. 00:22:07

They're so easy to build. 00:22:08

They're so easy to build. 00:22:09

They're so easy to build. 00:22:10

One of my favorites is the Boomerang that I'm sitting in. 00:22:12

It is a very safe, long-range, light twin airplane, 00:22:16

and it's the airplane that I fly nowadays. 00:22:20

Behind me is the Proteus, 00:22:23

a high-altitude airplane 00:22:25

that's used for special missions. 00:22:27

Probably my most famous airplane, though, 00:22:30

is the Voyager. 00:22:33

The Voyager, about 16 years ago, 00:22:35

took off at one airport 00:22:38

and flew completely around the world, 00:22:39

taking some nine days, 00:22:42

and landed at the same airport without refueling, 00:22:44

and that set a milestone in aviation. 00:22:47

Do you have to use your imagination 00:22:51

to design these planes? 00:22:52

Oh, yes. 00:22:54

Imagination is extremely important 00:22:55

because with an airplane, 00:22:57

you can look at birds, 00:22:59

you can look at other airplanes, 00:23:02

but if you're going to do anything truly new, 00:23:04

you have to create, 00:23:06

you have to innovate, 00:23:08

and you have to imagine. 00:23:10

Here we are in the office, 00:23:12

and this is where airplanes are designed. 00:23:13

It starts with a sketch, 00:23:16

and a sketch comes from the mind. 00:23:19

It comes from, really, from your imagination. 00:23:21

You imagine what might fly well, 00:23:25

and you think about it real hard, 00:23:28

and you take a pencil to a piece of paper, 00:23:31

and you put on a piece of paper 00:23:35

the creative thoughts that are in your mind, 00:23:38

and that's what imagination is really all about. 00:23:41

Can you show us the Proteus? 00:23:44

Okay, this is Proteus. 00:23:46

Pretty big airplane. 00:23:49

It's designed to do some very interesting things. 00:23:51

It can fly very high. 00:23:54

It can fly more than 10 miles high. 00:23:56

So it's up above where the airliners fly, 00:23:59

and it can stay up there a long time, 00:24:02

and that's very useful for doing things 00:24:04

like studying the atmosphere 00:24:06

or relaying Internet data, 00:24:08

that sort of thing. 00:24:11

So let's take a look at it. 00:24:13

Even though this is a very big airplane 00:24:15

with a wingspan of about 90 feet, 00:24:17

it's actually quite light. 00:24:20

It only weighs as much as two cars, 00:24:22

but if you fill it up with fuel, 00:24:25

it weighs as much as four cars. 00:24:26

The wings are very long and slender and very smooth, 00:24:29

and that's necessary so the airplane can fly a long time. 00:24:33

The wings are filled with fuel, 00:24:38

and the fuel drains down 00:24:41

and is pumped up to jet engines, 00:24:43

and jet engines is what makes the thrust 00:24:46

that makes the airplane climb, 00:24:50

makes it fly, makes it stay up there. 00:24:52

And thrust is a very, very important thing for airplanes, 00:24:55

and thrust will help you win this contest. 00:24:59

I wonder if our plane has too much thrust. 00:25:03

What causes thrust in the plane? 00:25:05

I'd say the winding of the rubber band creates thrust. 00:25:07

The tighter I wind it, the more thrust it gives. 00:25:10

Let me try it. 00:25:13

I wonder if our plane needs more thrust. 00:25:14

What if we have too much power for the plane? 00:25:17

With all these questions, I think we need to go see an expert. 00:25:20

Who would know about this? 00:25:23

What about someone who flies a plane? 00:25:25

Let's talk to a pilot. 00:25:27

That sounds like a great idea. 00:25:28

Let's get up and go. 00:25:30

Wow, so this is a simulator. 00:25:39

I've never seen any simulator like this at the video arcade. 00:25:41

Well, it's not exactly like the arcade. 00:25:44

This is U.S. Airways' new Airbus A320 simulator. 00:25:46

We use it to train our pilots on our new Airbus aircraft. 00:25:48

In fact, we can simulate anything that the real aircraft can do. 00:25:51

I'm one of the treehouse detectives, and we're trying to win a contest. 00:25:54

But first, we need to know more about the force of thrust. 00:25:57

Can you help us? 00:25:59

Well, I hope I can. 00:26:00

We learned that we need to know more about thrust. 00:26:05

Well, thrust is one of the forces acting on the aircraft in flight. 00:26:08

It's produced by the engines, which propel the aircraft through the air. 00:26:11

Why does our plane bank to the left? 00:26:14

The movement of the ailerons creates drag, 00:26:16

and this drag tends to move the nose away from the direction of the turn. 00:26:18

We compensate for this with the rudder. 00:26:22

Wow, the Airbus must be really heavy. 00:26:24

The Airbus is quite heavy. 00:26:26

It can weigh up to 205,000 pounds. 00:26:27

That's 100 tons. 00:26:29

It can carry 169 people, 50,000 pounds of fuel, and 16,800 pounds of cargo. 00:26:30

With all this weight, the Airbus must need a lot of thrust. 00:26:37

You're right. 00:26:40

The Airbus has an incredible amount of thrust. 00:26:41

In fact, each engine can produce up to 32,000 pounds of thrust. 00:26:43

That is a lot of thrust. 00:26:46

I think we need to know about thrust and weight. 00:26:48

Well, you're right. 00:26:51

There's some great experiments you can perform 00:26:52

that will help you to understand that relationship better. 00:26:53

That's a good idea. 00:26:55

I'll see what I can find. 00:26:56

Thanks for letting me see the simulator. 00:26:57

You're welcome, Vic. 00:26:58

Good luck on your contest. 00:26:59

Okay, bye. 00:27:00

I wonder if there are any neat experiments 00:27:02

that would actually demonstrate the force of thrust. 00:27:04

Let's contact the NASA White Files Kids Club 00:27:07

and ask them if they've done any experiments on thrust. 00:27:09

I love the NASA White Files website. 00:27:12

It's awesome trying to solve our problems with other club members. 00:27:14

It's all about being on a team. 00:27:17

I wonder if weight affects thrust. 00:27:19

That's a great question. 00:27:21

I hope one of our club members didn't experiment on thrust. 00:27:22

Look, we have an email from a NASA White Files Kids Club 00:27:25

in Boone, North Carolina. 00:27:28

That's the state of the first flight. 00:27:29

Remember the Wright Brothers had their first flight 00:27:31

on December 17, 1903? 00:27:33

I went there. 00:27:35

See my Daniel Boone hat? 00:27:36

The town was named after Daniel Boone. 00:27:37

He spent a lot of time exploring and trekking 00:27:39

through the beautiful Appalachian Mountains. 00:27:41

Let's click here. 00:27:43

Hi, I'm Jennifer Parsons, 00:27:49

a fifth grader in Ms. Susan Caton's class 00:27:50

at Green Valley Elementary School in Boone, North Carolina. 00:27:52

We performed an experiment on thrust. 00:27:55

My classmates and I asked ourselves, 00:27:58

does weight affect thrust and acceleration? 00:28:00

Our hypothesis is if enough weight is added to the balloon, 00:28:03

then the thrust will not be able to lift the balloon. 00:28:06

Here's what you will need for the project. 00:28:09

A balloon, a straw, a string, 30 paper clips, 00:28:11

masking tape, a cup, 3-ounce size, 00:28:15

scissors, and a hole punch. 00:28:18

First, measure the distance from the ceiling to the floor. 00:28:20

Add 15 centimeters to that measurement 00:28:23

and cut a length of string for that amount. 00:28:25

Tape or tie the string to a spot on the ceiling. 00:28:28

Thread the straw onto the string, 00:28:32

stretch the string taut, and tape it to the floor. 00:28:34

Take the cup, and using a hole punch, 00:28:37

punch three holes evenly spaced around the top of the cup. 00:28:39

Now cut three pieces of string 30 centimeters long. 00:28:43

Tie one string to each hole in the cup. 00:28:47

Load the balloon, but don't tie it off. 00:28:50

Position the cup underneath the balloon 00:28:52

and tape the other end of the strings to the balloon 00:28:54

so that it looks like a hot air balloon with a basket under it. 00:28:57

Tape the balloon to the straw, lower it to the floor, 00:29:00

count down, and release. 00:29:03

Three, two, one, let's go! 00:29:05

Yay! 00:29:09

Mark how high the balloon rose on the string. 00:29:11

Measure and record your data. 00:29:14

Load the balloon up again. 00:29:16

Make sure it's the same size as before, 00:29:18

but this time add five paperclips to the basket. 00:29:20

Lower the balloon, count down, and release. 00:29:23

With each trial, add five paperclips. 00:29:27

What happened to the height of the launch as we added weight? 00:29:30

Here's what we concluded from our data. 00:29:33

As we added more paperclips, our balloon didn't shoot as high. 00:29:35

What did this experiment tell you about thrust? 00:29:38

Take a close look at our data. 00:29:41

As we added more paperclips, our balloon lost a lot of power 00:29:43

and it wasn't able to shoot as high. 00:29:46

We concluded the heavier the plane, the more thrust you need. 00:29:49

Okay, thanks for your help. 00:29:52

We'll ask Dr. D how vertical thrust relates to an airplane. 00:29:54

Bye! 00:29:57

From the Y-Files Kids Club at Green Valley Elementary School 00:29:59

in Boone, North Carolina. 00:30:02

This is all starting to make sense. 00:30:04

We learned that the plane's engine makes thrust, 00:30:06

and thrust moves the plane forward. 00:30:08

Wouldn't you think it would make sense 00:30:10

if a plane was heavier and needed more thrust? 00:30:12

Look at our entry. 00:30:14

If we have more thrust than needed, it could break our plane in half. 00:30:16

Dr. D's neighbor works with a lot of fast planes. 00:30:19

He's stationed aboard the USS Theodore Roosevelt. 00:30:22

He said maybe he could make some special arrangements 00:30:24

for us to come out and visit his ship. 00:30:27

This should definitely be our next stop, the USS Theodore Roosevelt. 00:30:29

Can you believe we are actually flying on a plane to a ship? 00:30:33

It's hard to believe the USS Theodore Roosevelt 00:30:36

is 80 miles off the coast of Virginia. 00:30:38

Can't wait. It's going to be some landing. 00:30:41

That was just an awesome landing. 00:31:04

Can you believe that we landed on an aircraft carrier 00:31:06

while it was moving? 00:31:09

I'm not sure it was so awesome. 00:31:11

My legs still won't stop shaking. 00:31:13

Just look at the size of this ship. 00:31:15

I know. It's huge. 00:31:18

Yeah, but the runway's so short. 00:31:20

I know. 00:31:22

Hi, welcome aboard USS Theodore Roosevelt. 00:31:23

I'm Lieutenant John Oliveira, your escort officer. 00:31:25

You guys must be the treehouse crew. 00:31:28

Lieutenant John Oliveira, your escort officer. 00:31:30

You guys must be the treehouse detectives that I've heard so much about. 00:31:32

Yes, sir, we are the treehouse detectives. 00:31:35

We've never seen such a big ship before. 00:31:37

Well, Theodore Roosevelt is a big ship. 00:31:39

Home to 5,000 sailors. 00:31:41

It weighs 97,000 tons. 00:31:43

If you put it on its end, it'd be as tall as the Empire State Building. 00:31:45

In fact, it has everything we need on board. 00:31:48

Everything? 00:31:50

Everything. 00:31:51

Gyms, hospital. 00:31:52

We even have a dentist. 00:31:54

And Gidon. 00:31:56

What is Gidon? 00:31:57

Gidon's snack food. 00:31:58

You're right. I could live here. 00:32:00

What is this area called? 00:32:02

This is the flight deck, and it's 4 1⁄2 acres. 00:32:03

This is where we launch the 71 airplanes we carry. 00:32:06

You can launch airplanes off this small runway? 00:32:09

He means we're going to be launched off this runway. 00:32:12

We can launch them pretty quick, and we use that to help with some catapults. 00:32:15

That's how we do it. 00:32:18

What are catapults? 00:32:19

Well, catapults are what we use to help launch our airplanes. 00:32:21

But let's go down to V-2 Division and talk to Senior Chief Spinner, 00:32:25

and he can explain that to us in a little bit more detail. 00:32:27

Hello, Senior Chief Spinner. 00:32:35

We need to learn more about the force of thrust. 00:32:37

Can you tell us about your catapults and how they create thrust? 00:32:39

Yes, I can. 00:32:42

A catapult is actually two sets of cylinders that run 300 feet long, 00:32:43

and within each cylinder is a piston. 00:32:48

And connected to the piston is a shuttle that extends above the level of the flight deck. 00:32:51

Not a space shuttle. 00:32:57

No, the shuttle is actually another object that connects to the aircraft 00:32:59

that we use when we're launching airplanes on the flight deck. 00:33:03

The shuttle can actually take an airplane from zero to over 160 miles an hour in about two seconds. 00:33:06

Now that's fast. 00:33:12

And a lot of thrust. 00:33:13

But what makes the shuttle go so fast? 00:33:15

When we want to fire the catapult, steam actually enters the power cylinders 00:33:17

and it pushes the piston, cylinder, shuttle, and the aircraft 00:33:22

to the opposite end of the catapult at a very high rate of speed. 00:33:25

Steam is really powerful stuff. 00:33:28

But where does steam come from on a ship? 00:33:31

Well, on a carrier, the steam comes from the ship's power plant. 00:33:33

That power plant consists of two nuclear reactors. 00:33:37

Nuclear reactors? Wow, they must create major power. 00:33:40

We wonder what it felt like to be launched off such a short runway off the deck. 00:33:48

So we contacted a real F-14 pilot. 00:33:52

It's like a somewhat violent roller coaster ride. 00:33:55

You get thrown back in your seat and in about two seconds you're going from zero to 150 miles an hour. 00:34:00

Bye, thanks. 00:34:05

Thank you. 00:34:06

Bye-bye, enjoy your cat shot. 00:34:07

That's really weird. It couldn't be him. 00:34:10

What? 00:34:14

I think I just shot some video of Dr. D. 00:34:15

Look over there. Call him. 00:34:17

Dr. D! 00:34:19

Huh? What are you guys doing here? 00:34:21

Well, what are you doing here? 00:34:24

Just doing a little research. 00:34:26

So are we, on thrust. 00:34:28

What did you learn? 00:34:30

We learned today that the plane has to be going about 160 miles per hour to get lift 00:34:31

and the catapults help the plane go that fast very quickly because of the short runway. 00:34:36

Dr. D, how does this compare to a regular airport runway? 00:34:40

An airport runway is 10,000 feet long, but a carrier's catapult runway is only 300 feet long. 00:34:44

That means the ratio of the airport runway to the catapult runway would be 10,000 to 300. 00:34:50

If you do the math and divide the airport runway length by the catapult runway length, 00:34:57

you will find that the airport runway is about 33 times longer than the carrier's catapult runway. 00:35:02

On a carrier, the catapult provides immediate thrust for the plane to take off that quickly. 00:35:07

Isaac Newton's laws of motion tell us that if you want to speed an object up, 00:35:12

you have to apply force to it. 00:35:16

That makes sense. 00:35:18

I have to push really hard on the pedals of my bicycle to make it go faster, quicker. 00:35:19

Very good. 00:35:23

But what would happen if you were pulling a wagon with your kid sister in it? 00:35:24

That would be a lot harder. 00:35:28

Isaac Newton also told us it takes more force if you want to speed up more mass. 00:35:30

In math, that's called a direct variation. 00:35:34

Wow, math is everywhere. 00:35:37

Oh, so that means if the plane is bigger or has more fuel or more cargo, 00:35:39

it needs greater thrust to make it to its takeoff speed by the end of the runway. 00:35:44

Watch this. 00:35:48

Wow, your plane really spun. 00:35:51

I don't think we want our plane to do that. 00:35:53

That's called roll. 00:35:55

I don't think we want our plane to do that. 00:35:57

That's called roll. 00:35:59

What many planes do to avoid roll is to have what's called dihedral angle. 00:36:00

That means having the wings tipped up like this in a V. 00:36:04

That made a big difference. 00:36:10

Looks like our plane's ready to take off. 00:36:14

I can't wait to try the catapult. 00:36:16

It's going to be so awesome. 00:36:18

Let's go. 00:36:20

Hold on. 00:36:23

Here we go. 00:36:24

So what's up? 00:36:30

Do the treehouse detectives still need to investigate drag? 00:36:31

Can they combine all that they've learned so far to make a plane fly faster and farther? 00:36:34

You can find out next time with The Case of the Challenging Flight. 00:36:39

There's something wrong with the plane. 00:36:49

Why does it go down and then turn to the left? 00:36:51

Maybe it has something to do with weight. 00:36:54

We learned that weight is the force opposite of lift. 00:36:56

Let's look at the problem board. 00:36:58

What should we do next? 00:37:00

We know that air flow and air pressure affect lift and lift affects flight. 00:37:02

We know that the size of the wings affects lift. 00:37:07

We need to know how gravity and weight affect flight. 00:37:10

I think we need to see an expert. 00:37:13

We need to go to NASA Langley. 00:37:15

Hey, my mom says they have an electronic classroom where we can talk directly to researchers at one of 10 NASA centers. 00:37:17

Wow, this is so neat. 00:37:26

This must be an electronic classroom. 00:37:28

It certainly is. 00:37:31

I'm Bob Starr. 00:37:32

Have a seat. 00:37:33

We heard you could hook us up with any NASA researcher. 00:37:34

Yes, I can. 00:37:37

In the electronic classroom, we use two-way audio-video communications over the phone lines. 00:37:38

And I found that NASA's Dryden Flight Research Center in California uses experimental planes to test out new futuristic ways of flight. 00:37:44

It tested NASA's first space shuttle before it went into space. 00:37:51

That sounds risky, too. 00:37:55

That must be where they find out if the new designs are going to really work. 00:37:57

Hey, I know a researcher who's an expert in stability. 00:38:01

His name is Al Bowers. 00:38:04

Let me try to contact him. 00:38:06

Hi, I'm Al Bowers, an aerospace engineer at NASA's Dryden Flight Research Center. 00:38:13

I understand you have some questions about airplanes. 00:38:18

We have a lot of them. 00:38:20

Could you tell us about weight, one of the four forces, and how it affects flight? 00:38:22

One way that weight affects an airplane is the way the weight is distributed. 00:38:26

The weight is distributed on an airplane so that there's a balance point, and that balance point is called the center of gravity. 00:38:29

How does the center of gravity help you design planes? 00:38:36

I'm glad you asked, because we use the center of gravity to determine where to place the wings on an airplane. 00:38:39

On a normal airplane, like this one, we place the wings just behind the center of gravity, and that helps to keep the front end of the airplane pointed forwards. 00:38:44

Our plane always flies to the right. 00:38:53

Is there anything we can do to fix this problem? 00:38:55

That's the purpose of the tail. 00:38:57

The tail of the airplane keeps the nose from going up too high or dropping too low or slicing off to the left or right. 00:38:59

Here, let me show you. 00:39:05

This is an F-104 Starfighter aircraft. 00:39:09

It has the center of gravity just in front of the wings where the lift is produced, and the tail is on the back end of the airplane. 00:39:11

All of that makes this a very stable aircraft. 00:39:18

Wow, what kind of plane is that next to you? 00:39:21

I've never seen anything like that before. 00:39:24

Oh, this is the X-29. 00:39:26

I'm sure you noticed right away that the wings are on backwards, and that we put the tail on the front of the airplane. 00:39:29

Backwards? And a tail on the front? 00:39:35

Yes, even backwards we can make it work with the tail on the front of the airplane, just like on Burt Rutan's airplane. 00:39:38

How can it fly like that? 00:39:44

Let me show you with this broomstick. 00:39:46

This broomstick is like a traditional airplane where the center of gravity is in front of the wings, and it's stable. 00:39:49

If we move it to a new position, the broomstick just follows along. 00:39:55

But the X-29 was unstable. 00:39:59

The center of gravity was behind the wings, and so it was like your egg crate airplane, and it didn't fly very well. 00:40:01

But on the X-29, we had advanced technology in the form of very fast computers. 00:40:10

Those computers could compensate for the instabilities in the airplane. 00:40:15

Let's go back to the broomstick for a second. 00:40:20

It's like your hand moving back and forth to compensate for the instability, and that was the way we were able to make the X-29 fly. 00:40:22

Wow, I never thought a plane like that would have been able to fly. 00:40:30

I guess we need to find our center of gravity and make sure it's in front of our lift. 00:40:33

Yeah, that'll make our plane more stable. Thanks for all your help, Mr. Bowers. Bye. 00:40:38

This plane is looking like a winner. 00:40:45

Especially now that we put a rudder on our plane and we moved the wings back. 00:40:47

It doesn't pitch. 00:40:51

And it doesn't bank anymore. 00:40:53

But I wonder if we're still missing something. 00:40:55

Dr. D, we still have a few questions. Do you think you can help us? 00:40:58

Sure. 00:41:01

Thrust is needed even when the plane is going at a constant speed. 00:41:02

Why is that? Does it have anything to do with drag? 00:41:06

Yes. Drag is what we call all the forces that act on an aircraft in a backward direction. 00:41:09

Let's try an experiment. 00:41:14

I'm going to push this cart. What happens? 00:41:16

It looks like it's not slowing down, but you didn't keep pushing it. 00:41:21

I didn't have to. Isaac Newton explained that once an object gets moving, 00:41:24

it stays moving in a straight line at a constant speed unless you apply a force to it. 00:41:28

Watch this other cart. 00:41:32

It slows down right away. There must be some force acting on it. 00:41:34

That's right. An object will only slow down if a force acts on it in the direction opposite to its motion. 00:41:38

What might that force be? 00:41:44

It looks like friction. That's the force when you rub two objects together. 00:41:45

Very good. 00:41:49

Does an airplane experience friction? 00:41:50

An airplane experiences a type of drag called air resistance 00:41:52

because of the air flowing over the wings and other parts of the body. 00:41:55

Have you ever tried to drive your bicycle into the wind? 00:41:58

Yes. It's really not very easy. 00:42:01

You've had some experience with air resistance. 00:42:04

So if the drag is less, we won't need as much thrust to keep it moving at a constant speed. 00:42:06

Correct. 00:42:10

So if we can find a way to reduce the air resistance, we've got it made. 00:42:11

That's not exactly right. 00:42:15

As it turns out, in addition to air resistance, there's another type of drag. 00:42:17

This is getting complicated. 00:42:21

Okay, we'll take air resistance first. 00:42:23

To understand how to reduce air resistance, it would be best to talk to an expert. 00:42:25

Of course, the best expert is nature. 00:42:29

Nature? I wonder what that has to do with drag. 00:42:31

Well, I know someone who observes nature to understand drag, and he can tell you all about it. 00:42:34

His name is Ben Anders. He studies birds, fish, and even insects. 00:42:38

That's our next stop. 00:42:41

Look over there. That man looks like he's studying the fish. 00:42:46

Dr. Anders, we're the treehouse detectives. 00:42:49

Oh, hi. 00:42:51

Dr. D said you could help us. 00:42:52

We're trying to understand the force of drag. 00:42:54

Dr. D says you use insects and marine life to help you in your research. 00:42:56

Yes, I do. 00:43:00

When I look at those shapes, I see airplane wings. 00:43:01

Airplane wings? 00:43:04

I guess I can see a slight comparison. 00:43:06

Why would you want to compare them to airplane wings? 00:43:08

At NASA, we study birds and insects and marine animals 00:43:11

to inspire new research on flight and on ways to reduce drag, 00:43:15

and we call this biomimetics. 00:43:18

Wow, that's a big word. 00:43:20

How do you do that kind of research? 00:43:22

Well, let me ask you this. 00:43:24

What do you think has a lower drag, a smooth surface or one with grooves in it? 00:43:26

I'm not sure. I would guess a smooth surface would have less drag, 00:43:30

but what's the right answer? 00:43:33

Well, normally a smooth surface does have lower drag, 00:43:35

but if you make the grooves very tiny and you shape them just right, 00:43:37

the groove surface has lower drag. 00:43:41

And we discovered that the shark's skin has those exact same tiny grooves to reduce his drag. 00:43:43

I wonder what other secrets he's holding. 00:43:48

This is so cool. 00:43:51

I wonder if we need to make some adjustments to our plane to reduce its drag. 00:43:53

Maybe we need to do a little more research. 00:43:56

Let's go back to the treehouse. 00:43:58

Bye. 00:44:00

Bye. 00:44:01

Good afternoon. I'm Ted Toon with this KSNN special bulletin. 00:44:06

Kids Science News Network has learned that the treehouse detectives may have an edge 00:44:10

in this year's Extraordinary Airplane Contest. 00:44:14

Our reporter, I Am Listening, is standing by. 00:44:17

Thanks, Ted. 00:44:20

I'm here in this airplane to show the viewers what the treehouse detectives have learned 00:44:21

that might give them a win in this year's contest. 00:44:26

We have learned that the detectives now know about thrust, lift, drag, 00:44:30

and gravity. 00:44:44

Back to you. 00:44:47

Thanks, I Am, for that exquisite report. 00:44:50

Stay tuned to KSNN to see if the treehouse detectives can solve the mystery of flight 00:44:53

and win the Extraordinary Contest. 00:44:57

You know, we might even have a chance at placing in this contest something other than last place. 00:45:00

Wouldn't that be amazing? 00:45:05

Let's see what else we can do to help us win this contest. 00:45:07

Let's use our problem board. 00:45:09

Well, we know that air resistance affects lift, and lift is one of the main forces of flight. 00:45:11

We also know that planes must overcome the pull of gravity. 00:45:16

We know that thrust pushes an airplane through the air, and different airplanes require different thrusts. 00:45:19

We know that drag is the opposite of thrust. 00:45:24

Drag is the aircraft's resistance to the movement through the air. 00:45:27

We need to know if the materials used in the manufacturing of a plane will affect their drag. 00:45:30

But how can we find out? 00:45:34

We can do a little research on the internet. 00:45:36

I'll just type in NASA Langley. I know they must do a lot of research on planes. 00:45:38

I heard they have a program called Structures and Materials. 00:45:41

Let's go there. I'll email our friends and our parents to let them know we're going. 00:45:44

What are you doing? 00:45:49

I'm just looking at some of our new lightweight materials. 00:45:51

We need to learn about weight. 00:45:54

Well, you just learned that thrust is opposite to drag. 00:45:56

And lift is what makes the airplane go up, and weight pulls it back down to the pull of gravity. 00:45:59

Yes, we just learned about that. 00:46:04

Well, in order for the airplane to fly, the lift force has to be greater than the weight of the airplane. 00:46:06

And the lighter the airplane is, the easier it's going to be to fly. 00:46:11

And the lighter the airplane is, the easier it's going to be to lift the airplane. 00:46:15

So for the same size wings, a lighter airplane will get easier lift? 00:46:19

That's exactly right. But there's another benefit of having a lighter airplane also. 00:46:23

There is? 00:46:27

Sure. For the same amount of force, or thrust, the lighter airplane will actually go farther. 00:46:28

As an example, let's say you're pushing two kids on a swing. 00:46:34

Who's going to go farther, the kid that's lighter or the kid that's heavier? 00:46:38

The lighter kid will go farther. 00:46:41

That's exactly right. So for the same amount of engine or thrust force, a lighter airplane is actually going to fly farther. 00:46:43

Aeronautical engineers say that the airplane has greater range or maximum flight distance. 00:46:49

Cool. 00:46:54

Yeah, and lighter airplanes actually use less fuel too, so they're better for the environment as well. 00:46:55

What research do you do here to make planes lighter? 00:47:00

Well, we're trying to figure out how to make the materials that airplanes are made out of a whole lot lighter. 00:47:03

You see, today, most airplanes are made out of metal, like this piece right here. 00:47:08

It's really strong, but it's also really heavy. 00:47:12

Man, that is heavy. 00:47:16

Yeah, it sure is. Well, we're researching something brand new. It's called composite materials. 00:47:18

Composite materials are really strong, but they're also really lightweight. 00:47:22

Here's a really big piece of composites right back here. Can you help me with this piece? 00:47:26

I don't know if I can help. It looks kind of heavy. I might not be able to lift it. 00:47:31

Give it a try. 00:47:34

Wow, that's really light. 00:47:36

It sure is. Composite materials are already being used in a lot of military airplanes because they're really lightweight, but they're also strong. 00:47:38

We're also looking at another kind of material that's really interesting. 00:47:45

It actually bends and twists when activated, or it can pop up and down when activated too. 00:47:48

What's that? 00:47:53

They're called smart materials. 00:47:54

Smart material? I'm a smart material. 00:47:56

Yes, you are. This is an example of a smart material. This is called nitinol. 00:47:58

And when you bend or twist it, it'll actually go back to being completely flat when you heat it up. 00:48:02

If you want to try bending it up, then I'll heat it up and I'll show you how it works. 00:48:06

There you go. That's great. 00:48:11

Now when we heat it up, it goes back to being completely flat, as you can see. 00:48:13

Wow, that's cool. But how is that going to help an airplane? 00:48:17

Well, you can take this material and put it in the wings of an airplane and make the airplane wings bend or twist, 00:48:21

or even simulate little pop-up feathers like what birds use to fly. 00:48:27

Why would you want smart materials to mimic a bird's flight? 00:48:31

That's a good question. Well, for their size, birds are really good flyers. 00:48:35

And we're hoping that if some of our smaller airplanes can fly more like birds and bend or twist their wings in flight 00:48:40

to adjust to different flight conditions while they're flying along, they can actually be much better flyers. 00:48:47

I don't think we can buy smart materials, but maybe we can make our egg carton lighter. 00:48:52

Maybe we should use a foam carton. 00:48:56

Yes, now we need to test it. 00:48:58

Or experiment. 00:49:00

Look, I bought some foam egg cartons. 00:49:03

Let's find the mass. First we'll find the mass of the paper egg carton. 00:49:06

It's 54.1 grams. 00:49:10

Now we'll find the mass of the foam carton. 00:49:14

It's 15.5 grams. 00:49:17

Wow, it's a little lighter. 00:49:22

That means 15.5 grams makes 38.6 grams less than the other one. 00:49:24

Remember what we learned. 00:49:31

Lighter materials will reduce the amount of weight on a plane and decrease the amount of thrust needed. 00:49:32

And less weight will also decrease the drag. 00:49:37

Wow, that should make our plane fly further. 00:49:40

Let's make another plane out of foam cartons. 00:49:42

Okay, let's throw it. 00:49:46

So what's up? Will the change in material to the foam egg carton help the plane fly farther? 00:49:50

What's the most important force of flight? 00:49:56

What will help the treehouse detectives win the contest? 00:50:00

Don't miss the conclusion of The Case of the Challenging Flight. 00:50:03

That's the best we've had yet. 00:50:13

It's great. Do you think changing to a lighter weight material made a difference? 00:50:15

Maybe the foam carton made a difference. 00:50:19

But we still need to know more. Let's go to the problem board. 00:50:21

We know that lift, weight, thrust, and drag are the main forces of flight. 00:50:25

Yeah, but we also learned about yaw, pitch, and roll. 00:50:31

We need to know how all these forces work together to form a really fast plane. 00:50:34

I think we need to talk to a pilot. 00:50:39

My neighbor is a Young Eagles flight leader. 00:50:41

If you would like to learn where a Young Eagles group is near you, just go to the NASA WIFOWS website. 00:50:43

It's so cool. Every year they give thousands of kids like us a hands-on experience flying planes. 00:50:49

And it's sponsored by the EAA, an international organization. 00:50:55

No way, a real plane? This is so cool. 00:50:59

I'll go. I've always wanted to fly a plane. 00:51:02

We'll put a rudder on our plane. It helps stabilize the plane. 00:51:07

This looks like it moves. What does it do? 00:51:10

This is an elevator. It helps the airplane go up and down. 00:51:13

When the pilot moves the control yoke inside the airplane, they pull back on it. 00:51:16

This elevator comes up and makes the airplane climb. 00:51:20

If they push forward, the elevator goes down and the airplane is going to descend. 00:51:24

During takeoff, are all four forces of flight being used? 00:51:29

Yes, they are. We always have gravity and drag. 00:51:32

We have to overcome those by creating the thrust and the lift. 00:51:35

We do the thrust with the engine, causing the propeller to turn at maximum power. 00:51:38

And then we use the elevator to create lift on the wings. 00:51:43

The best way to find out is, guess what? 00:51:47

What? 00:51:50

You're going to get your first flying lesson today. 00:51:51

Me, up in the air, flying? 00:51:53

Yep. 00:51:56

All right, I'm ready. Let's go. 00:51:57

That was so cool. I can't believe I was flying the plane. 00:52:07

I have a question. What's the biggest challenge you run into when you're flying a plane? 00:52:11

Seeing the ground when the weather is bad is the biggest obstacle. 00:52:15

I heard NASA Langley is doing some really cool research that will help pilots fly in foggy weather. 00:52:18

I think it's called synthetic vision. Have you ever heard about it? 00:52:23

Yes, I have. 00:52:26

Synthetic vision will give the pilots a clear electronic picture of what's outside. 00:52:27

Even when it's foggy or dark outside? 00:52:31

Yes. There will be a screen that the pilot can look at and see if there are mountains ahead. 00:52:33

Like a video game? 00:52:38

Almost. Synthetic vision uses satellite signals and global positioning systems to give the pilot a very sophisticated map. 00:52:40

And it will definitely help prevent aircraft crashes in the future. 00:52:47

That's so cool. I hope that by the time I become a pilot, synthetic vision will be in every plane. 00:52:50

This will be an experience I will always remember. 00:52:55

I can't believe I was really flying a plane. 00:52:58

You sure were. You did a great job. 00:53:00

Look, there's Dr. D. He made it. 00:53:04

Hi, guys. 00:53:06

Hi, Dr. D. I think we're ready for the competition. 00:53:07

So tell me, what helped you prepare your plane for the competition? 00:53:09

We learned that in order for a plane to have lift, the front edge needs to be higher up than the back edge. 00:53:12

That made a big improvement over last year's plane. 00:53:17

Then we needed to adjust the position of the wing so that the center of gravity was just a little ahead of the center of lift. 00:53:20

Before, we had the wing too far forward. 00:53:26

Don't forget the roll problem that we corrected with the dihedral angle. 00:53:28

That's right. Bending the wings into the V shape made a big improvement. 00:53:32

We learned that thrust was required even when the plane was moving at constant speed. 00:53:35

In order to avoid as much drag as possible, we made sure that there were not any ragged edges. 00:53:39

Yes, and we used larger wings than we did last year because it gave us more lift. 00:53:44

We kept the plane's weight to a minimum because the more weight you have, the more lift you'll need and the more thrust you'll need to keep the plane going. 00:53:48

You've learned a lot and improved your plane so much. 00:53:54

It's a wonder that it flew at all last year. 00:53:57

We are so excited. We think that we are going to win. 00:54:00

But even if you don't win, just remember all the things you've learned about how airplanes fly. 00:54:03

Yes, but winning is so nice. 00:54:08

Seagulls, get ready to yell. Let's get your goals. 00:54:14

Wow, this is exciting. 00:54:18

Yeah. 00:54:20

Today might even be our day. 00:54:21

Yeah, we worked really hard as a team. Who knows, we might even win this contest. 00:54:23

I think so. 00:54:26

I hope so. 00:54:27

Good times. 00:54:28

Welcome, young aviators. 00:54:30

Yeah. 00:54:32

Welcome to the great extraordinary airplane contest. 00:54:35

On this team, we have Mr. Dan Locke. 00:54:39

Yeah. 00:54:41

And the Baron Knights. 00:54:42

And over here, we have Mr. John Livingston. 00:54:44

Yeah. 00:54:46

And the Smith Seagulls. 00:54:47

All right. 00:54:49

The contest rules are simple. 00:54:50

The distance your plane flies will be measured from the point of launch to the point where the plane lands. 00:54:52

The top two teams will move on to the finals. 00:54:59

Are you ready? 00:55:02

Yeah. 00:55:03

Team members, move to the launching pads. 00:55:06

I'm getting a little nervous. 00:55:12

We have to win this trial to be able to advance to the next level. 00:55:13

Here we go. 00:55:16

Yeah. 00:55:27

We made it. 00:55:28

We made it. 00:55:29

Uh-oh. 00:55:30

Look who we're up against. 00:55:31

That team is tough, but we might be able to win. 00:55:32

Let's try. 00:55:34

Yeah. 00:55:35

This might be a tie. 00:55:45

It looks close. 00:55:46

Hand me the meter stick, please. 00:55:47

It looks like the Treehouse Detectives have won by a mere four centimeters. 00:55:50

Yeah. 00:55:55

We did it. 00:55:56

Good job. 00:55:57

Good job. 00:55:58

We won. 00:55:59

We won. 00:56:00

We won. 00:56:01

We won. 00:56:02

Yeah. 00:56:03

We won by four centimeters. 00:56:04

That's like one and a half inches. 00:56:05

Good time. 00:56:06

Good time. 00:56:07

Let's go for it. 00:56:08

All right. 00:56:09

The Treehouse Detectives have pulled off an extraordinary upset here at the airport. 00:56:10

The Treehouse Detectives have pulled off an extraordinary upset here at the airplane contest. 00:56:15

I'm with the winning team right now. 00:56:20

Kids, no one thought you would win today. 00:56:23

How did you do it? 00:56:25

We used a lot of science as inquiry. 00:56:27

This definitely helped us learn about the four forces of flight. 00:56:29

And we used our research notebook to keep a lot of data and notes on our experiment. 00:56:32

And it really worked. 00:56:36

We finally are winners. 00:56:37

It looks like we're all winners, kids. 00:56:39

Thanks for competing. 00:56:42

And good luck next year. 00:56:43

Thanks, IM. 00:56:45

And tell those kids to watch out because I'm already working on my plane for next year. 00:56:46

I'm Ted Toons saying so long from KSNM. 00:56:51

What is it good for? 00:56:56

Absolutely nothing. 00:56:59

I love this song. 00:57:01

Falling down, falling down, my dear lady. 00:57:04

Can you guys say hello? 00:57:26

Say hi. 00:57:27

Hello. 00:57:28

Say good morning, Mr. Chan. 00:57:31

Good morning, Mr. Chan. 00:57:33

Hello. 00:57:36

Alright, alright. 00:57:54

Teachers, check out the free CD-ROM, Exploring Aeronautics, enclosed with a teacher guide. 00:57:56

It's a great introduction to the fundamentals of flight with a timeline, quick time movies, and student activities. 00:58:01

The NASA WIFILES is made possible through the generous support of SeaWorld and Busch Gardens 00:58:11

and the NASA Langley Research Center's Aerospace Vehicle Systems Technology Program Office. 00:58:16

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Autor/es:

Office of Education

Subido por:

EducaMadrid

Licencia:

Reconocimiento - No comercial - Sin obra derivada

Visualizaciones:

448

Fecha:

28 de mayo de 2007 - 15:32

Visibilidad:

Público

Enlace Relacionado:

NASAs center for distance learning

Duración:

58′ 23″

Relación de aspecto:

4:3 Hasta 2009 fue el estándar utilizado en la televisión PAL; muchas pantallas de ordenador y televisores usan este estándar, erróneamente llamado cuadrado, cuando en la realidad es rectangular o wide.

Resolución: