Taking to the Air
ALAN ALDA I've never flown a plane in my life. No problem, they
said. With today's automated systems you can land a 747. On
this edition of Scientific American Frontiers, we'll find
out if they were right.
ALAN ALDA (NARRATION) We'll also meet a bird who's teaching a man
how to fly, a sun-powered wing that one day may fly forever,
a fisherman learning how life first took off, and some flying
robots with minds of their own.
ALAN ALDA I'm Alan Alda. Join me now for "Flying High," our special
ALAN ALDA (NARRATION) Dawn in California's Mojave desert. This
is the famous dry lake bed at Edwards Airforce Base. Of the
hundreds of experimental aircraft tested here over the years,
this has to be the strangest. It's a hundred-foot-long flying
wing, powered by the sun. At the edge of the lake bed is NASA's
Dryden Research Center. Bob Curtin is the solar wing project
CURTIN That's a hundred foot wing span.
ALAN ALDA A hundred feet, and it's all wing, right?
CURTIN That's right. It's all wing, there's no surfaces in
back like a normal airplane.
ALAN ALDA Why did you make it all wing?
CURTIN Well it's the optimum shape for something that you
need to, to make very light, and collect a lot of solar energy.
It happens to be a wing.
ALAN ALDA (NARRATION) Every inch of the wing is covered with wafer-thin
solar cells. Even so, there's not exactly power to spare.
ALAN ALDA How much energy are these solar cells collecting?
CURTIN They'll collect at noon about 6,000 watts, which is
about four hair dryers' worth of energy.
ALAN ALDA C'mon. Now wait a minute, wait a minute. You fly this
100 foot long wing with the energy that it takes to run four
CURTIN Exactly, four hair dryers.
ALAN ALDA (NARRATION) There's also a small reserve of battery power.
ALAN ALDA Is that how you keep it closed when it's in flight or
do you --
CURTIN Well, there will be more tape. There's, there will
be tape strips.
ALAN ALDA More tape...
CURTIN That's right, more tape. But you're right, I mean,
there is a lot of tape on this airplane.
ALAN ALDA This is the battery?
CURTIN This is the battery pack, it's, it weighs about 40
pounds, and it'll power the airplane for about three or four
NARRATION A plane of unusual interest is demonstrated at Rosemund
Dry Lake in the Mojave Desert. It is the latest model of the
Northrop Flying Wing...
ALAN ALDA (NARRATION) Forty years ago, the first flying wings were
flown from this same lake bed. They've always been the Holy
Grail of aircraft design, because lifting only the wing into
the air, with no fuselage, offers the ultimate in lightness,
speed and efficiency.
NARRATION ... up to 100 miles an hour. Now a preview of the
flying wing transport of tomorrow...
ALAN ALDA (NARRATION) The cargo or passengers simply travel inside
the wing itself.
NARRATION ... inside the wing. And future air travelers will
really see something. Snug as bugs in their magic carpet,
ALAN ALDA (NARRATION) It was the high cost of development, rather
than technical problems, which led to wings being abandoned
in the early fifties.
ALAN ALDA These are little tiny wheels on this. It looks like the
wheels that you'd find on a stroller.
CURTIN Exactly. Those, they are baby carriage wheels in fact.
ALAN ALDA They're from that?
CURTIN Yeah, that's right.
ALAN ALDA (NARRATION) The wing combines the ultimate in design
with the lightest construction.
ALAN ALDA When you look through this transparent material here,
it's almost like looking at a model airplane.
CURTIN That's right.
ALAN ALDA There's little struts like something like what I used
to carve out of balsa wood when I was a kid.
CURTIN It's very similar to a model airplane. The ribs that
form the wing shape that are made out of Styrofoam. They're
made out of balsa wood in model airplanes, but very similar.
ALAN ALDA (NARRATION) Hollow Kevlar propellers are driven by high-tech
electric motors. Each streamlined cone weighs less than one
ounce. The entire plane, with six motors, the battery pack
and sixty pounds of solar cells weighs under five hundred
pounds. The quest for super-light planes goes back to the
seventies, and the vision of this man, Paul MacCready. He
was struggling to win the valuable Kremer Prize for human-powered
flight. There was a strong incentive -- he was seriously in
MacCREADY Suddenly this light bulb just glowed over my head.
Hey, that prize is just the amount of the debt. How, what
a remarkable coincidence.
ALAN ALDA So all you had to do was come up with what they were
giving a prize for.
ALAN ALDA (NARRATION) The Gossamer Condor did win. MacCready paid
off his debt, and in the process a new kind of flying was
born, tailored to very low power.
ALAN ALDA What do you think is the key ingredient here that helped
you win that prize?
MacCREADY Well, the final configuration key is large and light.
ALAN ALDA (NARRATION) MacCready's next plane crossed the English
Channel, and then another light bulb went off -- almost literally...
Solar power. He realized that because his planes were now
so efficient, maybe he could use just the sun to drive them.
At first, he added solar cells to a human-powered plane. With
this combination, the Solar Challenger also crossed the English
Channel. But now his latest vision does away with the human
component. MacCready's new idea -- the perpetual airplane,
that flies forever. The flying wing is a big step in that
direction, but it can't yet carry enough batteries to power
it through the night, when the sun doesn't shine.
CURTIN We have a bit of a tail wind right now, so I think
we should rotate the airplane around about 180 degrees.
ALAN ALDA (NARRATION) The Pathfinder, as it's called, has so far
flown only at a thousand feet or so. Now the team is preparing
for the first high-altitude flight. In this test, only three
of the six motors are installed. They're running on the sunlight
that's now falling on the wing. Yet it's so light, the engineers
have to hold it back. It'll take off, either from the blowing
wind or the movement of the plane, at just nineteen miles
an hour. Take-offs are always timed for dawn, when the desert
air is at its calmest.
CURTIN We're going to try to fly the airplane as high as it
can, as high as it can fly, basically. And as long as weather
holds - right now the weather isn't looking very good.
ALAN ALDA (NARRATION) On this day, the winds became dangerously
high for the fragile plane. For several days the team rolled
the wing out to the lake bed at dawn.
CURTIN So the wind is blowing at about 7 miles an hour; we're
at our limit. We don't want it to get much higher than this.
ALAN ALDA (NARRATION) And then they rolled it back to the hanger
to wait for the next morning. Finally, with winds no more
than five miles an hour, the first high-altitude flight was
ready for launch. Of course the wing has no pilot, so it will
be flown remotely from the ground. Takeoff will be handled
from a nearby chase van.
Everybody ready? CO-
CURTIN I'm ready.
-- looks good, go for a throttle up.
Four and five, on...
ALAN ALDA (NARRATION) At full power in the morning sun, the wing
accelerates across the lake bed. The nineteen mile-an-hour
lift-off speed is reached within seconds.
Main's lifting off. Nose wheel's lifting off. Ten feet. Airspeed's
27. 60 feet. Airspeed hold on at 27. 30 feet per second.
CURTIN Maybe around 600 feet, 5-600 feet right now. It was
a good climb out.
ALAN ALDA (NARRATION) As the wing gently spirals up from the desert
floor, it's followed with cameras more used to observing the
space shuttle. And that's appropriate, because MacCready's
idea is that perpetual solar wings, circling at high altitude,
can replace space satellites as platforms for observing the
I wonder if we'll ever see it again.
CURTIN I hope so.
ALAN ALDA (NARRATION) Today the crew is going to see how high they
can push the Pathfinder.
CURTIN We're at 33,000 feet, things are going well. No serious
problems right now. In fact we don't have any problems right
ALAN ALDA (NARRATION) They'll work from a control room in an old
CURTIN Now select waypoint 98.
OK. Waypoint 98.
CURTIN We are heading towards a high wind area at 40,000 feet.
ALAN ALDA (NARRATION) Now comes a big hurdle. They have never before
flown the wing through the strong winds of the jet stream.
But the on-board camera shows the flexible structure riding
the turbulence beautifully.
We're going to increase the speed a little bit because we're
not doing so well in the climb.
ALAN ALDA (NARRATION) By late afternoon it's clear that because
of greater than expected winds they won't make their sixty-five
-thousand-feet goal. But it's still been a flight that's broken
the altitude record for solar-powered planes by an enormous
forty thousand feet.
CURTIN The sun is going down now. We still have a climb rate
so we're climbing. But at some point the sun's going to get
low enough that our climb rate goes to zero. And, and when
the climb rate goes to zero, we'll be at our maximum altitude.
There it is, five zero zero zero zero.
CURTIN This is an extraordinary flight; now we've just got
to get it home.
ALAN ALDA (NARRATION) They switch to the onboard batteries to bring
the plane back in the darkness. The next model will store
enough power to stay up here until the sun rises again. We're
back on the lake bed, two hours after sunset.
CURTIN 300 feet.
I guess we're higher than that. OK, you want to slow down
a little ...
ALAN ALDA (NARRATION) MacCready's vision is back on earth. And
that's where his thinking stays firmly planted.
Beautiful, that's the most beautiful thing that I've ever
seen in my life.
ALAN ALDA You know I see a theme running through all the work you've
done, which is doing more with less. What does that mean to
MacCREADY More with less is an absolutely necessary part of
a future world that works. We can't just consume energy, consume
materials at the rate we're doing it here in an advanced country,
while at the same time there are more people around the earth
all the time. And the earth isn't getting any bigger. We have
to do more with less, and we can do so much more with less.
back to top
TO THE AIR
ALAN ALDA (NARRATION) A third of a billion years ago, life on earth
took a giant leap-- into the air. And it was never the same
again. George Ruppel is one of the world's great students
of insect flight. Among his favorite subjects: dragonflies.
RUPPEL Here we have caught a large dragonfly, one of the best
fliers we have.
ALAN ALDA (NARRATION) And dragonflies not only have powerful wings
RUPPEL Always, it will bite me. Ouch.
ALAN ALDA (NARRATION) We met George Ruppel a couple of years ago
in Germany, where this marsh is one of his favorite spots
for stalking dragonflies.
ALAN ALDA How do you look for them? Do you scan with your eyes
or do you --
RUPPEL Yes, I scan with my eyes and then I detect the blue
and black bodies.
ALAN ALDA (NARRATION) Like most scientists who study flying creatures,
Ruppel employs slow motion photography. But George shoots
his movies on location rather than in the laboratory.
ALAN ALDA So what's the idea? Why come out to the pond and shoot?
Why don't you take the dragonflies into the laboratory where
the conditions are controlled?
RUPPEL Yes, controlled, but the dragonflies don't behave normally.
They only show here in natural conditions their full behavior.
And even their full flight behavior. And therefore we have
to go out. Please let, have a look. There is a dragonfly sitting
on the stem. I can, I hope, film it.
ALAN ALDA (NARRATION) What fascinates George Ruppel about dragonflies
is how they use their flying skills in their everyday life.
For example, male and female dragonflies often fly in tandem
pairs after they mate. The female has to dip her tail into
the water to lay the eggs the male has fertilized. By riding
shotgun like this, the male is keeping his rivals at bay.
Here one of those rivals switches from hovering flight to
full forward thrust in an attempt to dislodge the first male
from his mate. A third male briefly joins the dogfight-- and
in the confusion the first male gets dunked. The attacker
switches to high power backward flight as he pulls away with
the female. The aerobatics continue as the new male flips
the female into a somersault, apparently expelling the eggs
the first male fertilized. Now the newcomer has a chance for
fatherhood. Breaking free of both land and water some 350
million years ago, flying insects became the most successful
life form on the planet. Flying insects make up 60 percent
of all living species known to science-- even if their flying
skills sometimes fail them. But how insects came to fly is
one of the great mysteries of evolution. Where did wings--
and all the complex muscles and nerves needed to operate them--
come from? As the woods and rivers of eastern Pennsylvania
began waking up from their winter deep freeze, we joined biology
professor Jim Marden and his student Melissa Kramer in a hunt
for clues to the origins of insect flight. One of these clues
lies beneath the water, where many insects begin life as swimming
larvae-- like this mayfly.
MARDEN Have you seen him before?
ALAN ALDA (NARRATION) Its gills beat in the water like miniature
oars, and many biologists now see these flapping gills as
the forerunners of flapping wings. But that still leaves the
thorny question of just how oars became wings. If evolution
proceeds in steps, with every step being useful for something,
what use is something halfway between an oar and a wing? It's
a question Jim Marden now believes he may have answered --
thanks to his love of fly fishing.
MARDEN Well in fly fishing you're tying some feathers and
string on a hook in order to imitate an insect; but that's
only half the battle. Because then you have to come out here
in the stream and present it to the fish in the right way.
And so fly fishing made me a real student of the behavior
of insects on water.
ALAN ALDA (NARRATION) And it was while watching insects on water--
especially a group of winged but flightless insects called
stoneflies-- that Jim Marden suddenly saw what good a half-wing
could be. Stoneflies often emerge from their larval form in
the middle of a river, and need to get to shore quickly in
order to find a mate. Stoneflies are drab and uninteresting
even to most biologists-- unless you're planning an experiment
to find out if wings evolved first not to fly in the air,
but to skim across the surface of the water.
MARDEN OK, I'll see if we can get one.
ALAN ALDA (NARRATION) Back in the lab, the Pennsylvania State University
biologists found their stoneflies to be highly cooperative,
behaving in front of a high speed video camera just as they
do in the river.
MARDEN Here she is, and we've just dropped her in the water.
She's struggling to get free of the surface tension. Here
she's raising up and trying to get the tip of her abdomen
pulled off the water there. The trick the surface skimming
is, we've found, they have to really get up on top of the
water. It doesn't work if any of them is touching the water,
except their tips of their legs. There. Now she's ready and
off she goes. And she's nice and stable and off-screen flapping.
You still see her flapping into the shadow. There she goes.
ALAN ALDA (NARRATION) This use of wings to propel an insect across
the surface of water is what Jim Marden believes to be the
missing link in the evolution of flight. Most of the experiments
to test this hypothesis were run by Melissa Kramer.
KRAMER What I'm doing is videotaping these stoneflies surface
skimming from above, with a centimeter (inaudible) underneath,
so that I can get their velocity. I can measure the time that
it takes them to run a certain distance by getting that off
of the videotape.
ALAN ALDA (NARRATION) With the slow-motion replay, Melissa can
count the number of video frames it takes for the stonefly
to skim a certain distance. The insects average about 1 1/2
feet per second. Then she clips the insect's wings with a
pair of nail scissors, and measures the speed again. The insects
are slower-- but not by much. Now here's the critical test.
When she clips the wings to mere nubs-- less than a quarter
of their original length-- the stoneflies can still use them
to skim around on the surface of the water. So even a nub
of a wing-- a wing much too short to allow flight-- can be
useful. And completes an evolutionary pathway along which
gills could have become oars, oars flapping sails, and flapping
MARDEN Well the Darwinian idea of evolution is a gradual,
step-wise process. And so right from the time that Darwin
first proposed his ideas, he was attacked on many fronts.
One front was how do you get highly complex traits that only
work in their full blown and fully-integrated form? "What
good is a nub of a wing?" is a direct quote from one of Darwin's
contemporaries. So one of the things we're out here doing
with these stoneflies is showing what nubs of wings really
are used for.
ALAN ALDA Do you have one started in there now?
HUTCHINS Yeah, they're flying in there now.
ALAN ALDA (NARRATION) I'm at NASA's Ames Research Center near San
Francisco. Ed Hutchins and I are about to go for a spin.
ALAN ALDA So what does this represent? What kind of plane is this?
HUTCHINS This is a 747-400. We're ready to go.
ALAN ALDA Where should I sit here?
ALAN ALDA (NARRATION) Ed's an expert in a subject that affects
every airline passenger -- computerized flying.
ALAN ALDA Is it this tight in a real 747?
HUTCHINS All of the dimensions are the same.
ALAN ALDA (NARRATION) To see what the computers do, I'm going to
try flying this simulator without their help.
HUTCHINS When I say rotate you will ease back on this yoke.
You'll come back about 3 inches, and that's going to lift
the nose of the airplane off the runway. CONTROLLER NASA 2001,
the wind is calm, you're clear for take-off.
ALAN ALDA We're moving.
HUTCHINS Yes. And there we go, we're going to takeoff thrust.
And rotate -- Alan, bring the yoke back.
ALAN ALDA Oh, what, what? Rotate already?
HUTCHINS Yeah, rotate already. You're doing fine.
ALAN ALDA Too fast?
HUTCHINS No, that's good. Positive rate. Gear coming up. You're
doing great. Bring the nose down just a little bit.
ALAN ALDA Oh no. This is making me sick here.
ALAN ALDA (NARRATION) We're still flying, but now here's San Francisco
ALAN ALDA God, I, I hope we don't land in the water. I don't like
ALAN ALDA What, sink rate?
ALAN ALDA Pull up. Pulling up, pulling up.
ALAN ALDA Oh, I don't like this.
HUTCHINS Now you can see, you've got two runways there. I'll
take either one or between them.
ALAN ALDA You mean I've got to look at it by sight and pick the
HUTCHINS Yeah. This would be a good time to start thinking
Sink rate. Sink rate. Pull up.
ALAN ALDA I'm pulling up, pulling up.
ALAN ALDA Pulling up.
Pull up. Sink rate.
HUTCHINS Now push forward a little bit, we've got to get down
to it. Good, good. There's the runway. Now just put us on
ALAN ALDA Oh sure, easy for you to say. I'm too, I'm too far up,
I've got to go down. Oh, I'm going down nose first. Oh, I
don't... I've got to go down a little more, too, too much...
oh, I think I'm crashing.
HUTCHINS No, you're on it, you're on it. Perfect. Get the
ALAN ALDA I crashed.
HUTCHINS That's, the red means we're dead.
ALAN ALDA We're dead.
ALAN ALDA What did I do wrong?
ALAN ALDA (NARRATION) After a miraculous recovery, we go around
again -- this time with all the automation switched on.
HUTCHINS We now have the runway in sight, and we're clear
ALAN ALDA At this point I was flopping my wings all over the place.
ALAN ALDA This is, this is nice and smooth here. How close are
ALAN ALDA Fifty, oh thank you.
ALAN ALDA Aha. I see, it's moving here.
HUTCHINS Touch down.
ALAN ALDA (NARRATION) A perfect landing. Modern jet liners are
all highly automated. Computers operate the controls, run
the engines, navigate the route and make the landing. Overall,
these kinds of planes are far safer than the old manual types.
But automation brings problems of its own. The crew of this
Airbus thought the computer would protect the plane. The computer
thought they were landing. When humans don't know what the
computer is thinking, it can lead to tragedy. Engineers like
John Hansman at M.I.T. call it "mode confusion," and it begins
right here with the cockpit instrument displays. This one,
from a 747, works fine. The purple line maps the course that
the computer will automatically fly -- through these star-shaped
waypoints. That's called "navigation mode". Or the pilot can
select "heading mode", and have the plane simply fly in a
set direction, represented by this dashed line. Mode confusion
is possible, but not serious in this case.
HANSMAN Even if the pilot were to forget that he or she was
in heading mode here, it's not a very severe case because
once you flew by the turn point or waypoint you would see
in the map in front of you that in fact you weren't going
the way you thought. So you could very quickly catch that
error and correct it.
ALAN ALDA (NARRATION) In contrast, here are the controls for what's
called "vertical navigation" -- going up or down. The computer
can seek a particular altitude, hold at a given height, or
climb or descend at a set rate. But there's no simple visual
display of what the plane's doing -- it's all knobs and numbers.
In the winter of 1988, it was knobs and numbers that got one
of these planes into trouble. An Airbus A320 flew into a mountain
on a night approach to Strasbourg, France, with major loss
of life. Just before the crash, shifting winds had led controllers
to switch the plane from the normal runway to a secondary,
which has no electronic landing aids. So now the pilots had
to fly a standard procedure called a "non-precision approach."
HANSMAN In the non-precision approach what you do is you fly
level until you reach a certain distance from the airport.
And then you basically descend in a series of steps.
ALAN ALDA (NARRATION) The pilots knew that a descent angle of 3.2
degrees would line them up correctly with the steps, clearing
the mountains. So now they had to program that angle into
HANSMAN The way you would do this would be you would enter
3.2 degrees in the flight control unit by turning this knob
we've simulated here, and pulling that knob out.
ALAN ALDA (NARRATION) But the knob does two things. Depending on
the position of this button here, it either controls descent
angle in degrees, or speed of descent in feet per minute.
3.2 degrees is displayed like this, with a period. But 32
hundred feet per minute is displayed like this. The only difference
is the dot. On that night the pilots thought they'd set 3.2
degrees, but in fact had called for a 32 hundred feet per
HANSMAN So they descended at 32 hundred feet per minute, which
is a much steeper angle than 3.2 degrees, and descended them
basically into the mountain short of the runway. Clearly the
flight crew made the mistake. They flew the airplane in the
wrong mode and flew the airplane into the ground. On the other
hand, this is a case of what we would call poor human factors
engineering, in that the same knob and same display was used
for those two modes.
ALAN ALDA (NARRATION) After the Strasbourg crash, Airbus improved
the display in the A320. But the task of improving communications
between pilots and their computers isn't complete. Mode confusion
let to the crash of this Indian Airlines Airbus, and incidents
of mode confusion are reported with all makes of planes.
HANSMAN We're on our way towards Boston, and at some point
here we're going to have to start to descend to get into Boston.
ALAN ALDA (NARRATION) Here's a typical example. We're heading toward
a waypoint called "Milt". It's the town of Milton.
ASO 1, 2, 3; descend and maintain flight level 190 by Milt.
HANSMAN OK. The air traffic controllers just told us that
we have to descend to 19,000.
ALAN ALDA (NARRATION) John Hansman dials in the new altitude, then
tells the computer to stop holding at our cruise height, and
start descending at a particular rate. He dials in the rate
that will get us down to nineteen thousand at Milt. We start
to descend. Here's the altitude dropping through thirty four
thousand. So far, so good. But, we're just about to get into
HANSMAN This is actually a very rapid descent. In flying terms
it's what we call a slam dunk, where the controllers dunked
us right down on top of the airport.
ALAN ALDA (NARRATION) As our plane drops down, it naturally speeds
up. Here's our speed displayed, as we approach three hundred
and thirty miles an hour. Watch what happens. At three thirty
the computer reacts. Let's see that again, just as the speed
gets up to three thirty. Did you get it? One more time. Watch
the box at the top right. As we hit three hundred and thirty
miles an hour, the computer automatically goes into high-speed-protect
mode. That levels the plane out to keep our speed within the
safe range. But now we're going to come in above our assigned
altitude, maybe where there's other traffic. And we might
not have noticed.
HANSMAN Most pilots will catch that type of situation very
quickly and will in fact anticipate that the airplane would
switch modes. The issue really comes in more complicated real
world situations, where you're not just sitting looking at
the screen, but in fact you're trying, maybe trying to get
weather information. You may be dealing with a passenger in
the back having a problem. You may have, be worried about
fuel or things like that.
ALAN ALDA (NARRATION) John Hansman is developing a new cockpit
instrument, to help pilots understand the vertical situation.
In the descent to Milt, for instance, his new instrument alerts
the pilot that the plane will automatically ease-up in the
descent, and that it will be too high when we reach Milt.
It's generally agreed that automated cockpits need this kind
of vertical display. Compared to the old days, computers have
made flying a lot safer. But they've also made being a pilot
a different kind of job.
HANSMAN It used to be that if you were very good and smooth
on the stick you, you were a safer pilot. Nowadays safe pilots
are pilots who really know how to manage the systems and manage
ALAN ALDA (NARRATION) Back at NASA Ames, Ed Hutchins is showing
me his version of a new vertical display. And it was here
during this night simulation that I suddenly understood what
an amazing challenge flying is.
ALAN ALDA I've been in the cockpit of a plane once or twice because
the pilot invited me up. It was always in the daylight.
ALAN ALDA And this is the first time I get a sensation of what
it must be like for a pilot to fly through this inky darkness.
And I realize how totally dependent you are on, on all this
information here. There's nothing to, no possible way, is
there, to guide yourself visually?
ALAN ALDA (NARRATION) Automation has made flying safer. And to
make automation safer, pilots and their computers are learning
to understand each other better.
ALAN ALDA (NARRATION) People wanting to fly have long drawn their
inspiration from birds. Not that it's done them much good.
Only when we swapped flapping wings for fixed ones-- and not
always then -- did we finally get off the ground. In the almost
100 years since those earliest flying machines, planes haven't
changed much in their basic design. Fixed wings, powerful
engines, wheels-- all very un-birdlike. But pilot and biologist
Ken Dial continues to look to birds for inspiration.
DIAL What turns me on about flight is that I get to pretend
to be a bird at least once in a while. But I realize that
I do it in a very stilted fashion and nothing as beautiful
and as elaborate as a bird can fly.
ALAN ALDA (NARRATION) To understand better how a bird can fly,
Ken watches them closely while they do it-- here in a wind
tunnel at the University of Montana. This is a magpie flying
at cruising speed-- about 12 miles per hour. A muscle sensor
reveals how much energy the bird is using.
DIAL OK, let's give it a little more speed.
ALAN ALDA (NARRATION) When the wind speed is cranked up, the magpie
flies faster-- but according to the muscle sensor, with very
little extra effort. Even approaching 30 miles an hour-- its
maximum speed-- the magpie uses energy with great efficiency.
The bird's secret is that it's able to adapt its whole body
to the faster flight.
DIAL When the bird's flying very quickly, the tail will pretty
much take the form of the body to reduce drag. When it wants
to maintain a high speed, it will become horizontal with the
air flow. Its feet will go and retract, beautiful, retractable
gears underneath the feathers. You'll see that it opens its
mouth when it flies faster. We believe that it's actually
ramming air down into the respiratory system and blowing up
like a balloon.
ALAN ALDA (NARRATION) While birds can fly fast very efficiently...
slow flight is much harder work... as the muscle sensor shows.
But here again, the bird adjusts its whole body, flaring its
tail for extra lift, dropping its feet and steepening its
body angle to increase drag. Airplane designers have adopted
a few bird tricks-- flaps for extra lift on take offs and
landings--a retractable landing gear. But by comparison with
a bird's ability to use its whole body, pilots have only a
few moving surfaces to work with-- like ailerons for turning.
To study how birds turn, Ken Dial's students are setting up
a slalom course for pigeons in a corridor of their University
of Montana laboratory. The pigeons first have to learn the
course. A couple of practice flights, and they skillfully
weave between the barriers. Once again the birds are equipped
with sensors to see how their muscles perform... And the flight
is recorded on slow-motion video.
DIAL One wing beat goes from straight and level to about 120
degree, bang, in one wing beat, which happens in about 100,
120 milliseconds, tenth of a second. In the next wing beat
it rights itself. Now that's pretty impressive for a bird
as big as a pigeon to be able to turn that fast and recover
in two wing beats.
ALAN ALDA (NARRATION) The information he gets from the video and
the muscle sensors inspires Ken to don a pair of wings himself.
DIAL If a bird is going to make a left turn, it's going to
supinate or increase its angle of attack on the outside wing.
And it's going to pronate or decrease the angle of attack
on its inside wing. And it would be able to then develop the
proper angular momentum to make this turn. What complicates
this unfortunately is that it begins all of these twisting
actions of the entire wing to make this turn when the wings
are fully extended up above the bird's back. And so that now
I'm going to make my right turn, I'm going to actually decrease
the angle of attack on this wing, increase the angle of attack
on this wing. And go through my wing beat to make my right
ALAN ALDA (NARRATION) Recently, Ken Dial has begun literally peering
inside his birds as they fly.
DIAL What's interesting this tape (laughter) is first of all
you're looking at x-ray. You're looking through the feathers,
the skin, and seeing some of the outlines of the muscles.
With the retractable gear of his legs really hidden by feathers,
and then its neck which is entirely hidden by feathers and
skin. We think it's a fabulous area of research to, I'm trying
to understand this independent suspension system that birds
have. Now watch the head. Watch how it can sit pretty much
still in space as the body oscillates up and down, providing
the lift and propulsion that this locomotion machinery has
to, while the cockpit has to keep literally an eye on where
it's going and what's it, its intentions are.
ALAN ALDA (NARRATION) Ken's research is now moving into a third
dimension. Pigeons equipped with tape that reflects infrared
light fly in front of an array of infrared cameras. The simplified,
computer-generated 3-D images of the flight-- along with the
X-ray images of flying birds-- will give an unprecedented
insight into how birds achieve such mastery of the air.
DIAL I think once we put the feathers on this it's going to
move right off the screen.
ALAN ALDA (NARRATION) Ken Dial's research into bird flight leads
him right back to what separates birds from airplanes. When
plane designers long ago abandoned birds as practical models
for human flight, they did so because of one huge advantage
rigid planes have over flexible birds: stability
DIAL We're really in a very stable airplane right now. That
is I could pull the power, I could let me hands off of the
controls, and we won't go spiraling out of control. So here
goes the power, here go my hands. Now we're not spiraling
out of control; we're about a mile above the ground so I have
time to recover if I want to. The power is effectively off
right now, I'll pull it a little, even more. And I'm not touching
the plane. Now a bird, if he decided to just shut the computer
off, that is the controls and the thrust, it would tumble
and fall and crash and burn, much like when a hunter shoots
a bird, hits it squarely, the computer is out, and so are
all the flight surfaces. But now I can go take control of
the plane, put in some power, climb back up to altitude, and
you can see we didn't go through any great discomfort or any
ALAN ALDA (NARRATION) For most of aviation's history, the un-birdlike
but stable airplane has been the only way to fly. But today's
newest planes are very different. The X-29 experimental aircraft,
for instance, is so unstable that it simply cannot be flown
without a computer -- but just like a bird it's extraordinarily
agile in the air.
DIAL We're moving into this new arena with fantastic computers,
with sensory receptors. With aircraft that are being built
inherently unstable, but with computers to keep the upright.
Well that's what a bird does but it's got a hundred million,
150 million years head start on them, and I still think we
have a tremendous amount to learn from our feathered friends.
ALAN ALDA (NARRATION) It's taken almost a century-- and our most
sophisticated technology-- but at last we are learning how
to fly like the birds.
ALAN ALDA (NARRATION) Dawn in Atlanta. And competitors-- many exhausted
from working all night-- are gathering at Georgia Tech for
a contest that has never been won. It's a contest between
flying robots. Here's the task. With no one at the controls,
each robot must take off from one corner of a 60 by 120 ft.
field, then find and fly to a ring containing 6 metal disks.
Still without human control it must pick up the discs one
at a time and carry them over a 3 ft. barrier to a second
ring, where the discs are deposited. In five years of competition,
no robot has even come close to completing the mission. First
on the field this year is a blimp from the Technical University
of Berlin, Germany.
ALAN ALDA Have you tried this out on a field back home?
FINKE Yes, but inside.
ALAN ALDA Inside?
FINKE Yeah, it's working very well inside. We still have some
problems with the (inaudible).
ALAN ALDA (NARRATION) Like all the robots here, once it starts,
it's on its own.
STUDENT OK, and we are autonomous.
ALAN ALDA (NARRATION) And at once the Berlin blimp demonstrates
why the contest is so difficult-- especially for blimps. Its
six battery-powered propellers try hard to steer it toward
the ring - but the gentle dawn breeze wafts it away.
ALAN ALDA Has it lost control, do you think it's --
MICHELSON No, not completely.
ALAN ALDA (NARRATION) As Marion dashed off to help rescue her balloon,
I sought out the contest organizer, Rob Michelson.
ALAN ALDA What do you think happened there?
MICHELSON They had the props going as hard as they could down,
and they were able to catch it before it went into the power
lines. But that's the problem with a blimp.
ALAN ALDA (NARRATION) Taking a radically different tack is the
next robot. This is the fifth consecutive year the University
of Texas at Arlington has entered what amounts to a flying
ALAN ALDA Just from your previous years' experience, what's it
like once you throw the switch and the thing starts to go
on its own, you can't do anything? All the work you put into
it matters, but you can't do anything at that point.
STUDENT 1 This, this year different from the previous years,
I'm really, really nervous because this is the closest we've
ALAN ALDA (NARRATION) The first year of the contest, the Texas
tailsitter was one of the few machines even to get off the
ground-- briefly. Last year-- after 3 years improving its
control systems-- the tailsitter flew beautifully. The problem
was still the landing.
First thing I need you to (inaudible) show me is how your
emergency set up --
ALAN ALDA (NARRATION) This year, the contests' judges are taking
I want to see the emergency set up first thing --
ALAN ALDA He said he wants to see the emergency procedures. I want
to see your emergency procedures too. I'll be over here.
ALAN ALDA (NARRATION) What had caught my attention was what looked
like a giant inflatable pig. It turned out to be another blimp,
this one from the University of British Columbia.
ALAN ALDA Are you about to take off for the first time now?
STUDENT We were flying earlier. What we're going to try is
a manual flight just to see that the system is working, which
ALAN ALDA Do you know what the problem is?
STUDENT No, I don't, engine trouble.
ALAN ALDA (NARRATION) The engine got fixed. But the navigation
system-- involving a video camera watching the size and shape
of the black spots-- got confused by a glint of sunlight,
and the Canadian robot waltzed off the field. Meanwhile, last
year's best performer-- a helicopter from the University of
Southern California-- was also having a bad morning.
MONTGOMERY We crashed last night about 4 in the morning. It
was flying great, things were looking good. We were, we crashed
and something mechanically is wrong with it. The craft is
not functioning right.
ALAN ALDA (NARRATION) Despite improvised repairs...
MONTGOMERY -- let's reset, start again.
ALAN ALDA (NARRATION) ...and last minute adjustments, the USC 'copter
simply couldn't get off the ground.
MONTGOMERY Aagh! Man! You look at this, you know, you think
"Gees". You go pick up a disk, you carry it across the barrier
and drop it off. That's so simple, what's the problem? But
they don't realize that, you know, what's very easy for humans
is much more difficult for robots. You have sensing problems,
you have to deal with variables such as wind and such and
it's not a very trivial problem at all. It just shows you
just how flexible and adaptive humans are.
ALAN ALDA (NARRATION) I really liked this little device, designed
to pick up the discs when dangling from its helicopter.
MEMBER Pick it up, and we have --
ALAN ALDA That works really smoothly.
ALAN ALDA (NARRATION) The problem was it wasn't quite so smooth
once its helicopter was carrying it. But now the Texas tailsitter
was taking off, guided by scanning laser beams. It seemed
to be flying very nicely, but made no attempt to go pick up
any discs. Everyone seemed very pleased when it landed without
toppling over. I was a bit puzzled by all the excitement.
ALAN ALDA What happened?
STUDENT 2 That was a completely autonomous flight and we took
off, hovered, and landed completely autonomously.
STUDENT 3 That's world history for this competition; that's
the first time that's ever been done in this competition and
I've been here for five years.
STUDENT 2 We're pumped now. The next step is a disk.
ALAN ALDA (NARRATION) But now Stanford University was taking the
field. These guys looked like pros. And they had a navigation
system to prove it, employing the Defense Department's Global
Positioning Satellite System.
ALAN ALDA What is that thing over there?
ROCK That is a GPS antenna. That is our ground station. That
GPS antenna sees satellites in the sky and we basically fly
to that reference station. We have four of those little antenna
on board the helicopter. And the thing that's neat about this
is that with this new GPS technology we're able to tell you
where each one of these little antenna is to within a centimeter.
ALAN ALDA A centimeter?
ROCK A centimeter.
ALAN ALDA (NARRATION) Once the helicopter locked on to the satellite...
CONWAY The flashing red lights on the back of the helicopter
means that everything is working.
ALAN ALDA (NARRATION) The Stanford robot took off without a hitch.
ROCK This is flying under complete computer control right
ALAN ALDA (NARRATION) And unlike the other teams, didn't bother
ALAN ALDA Are you just going for autonomous flight now? Or are
you going to try to go over and get a disk?
ROCK We're going to try to pick up a disk right now. We're
flying the whole trajectory.
ALAN ALDA (NARRATION) To pick up a disc, the machine simply trawls
with a magnet.
ROCK Whoa! We're close. We're going to, he goes into a search
pattern so there'd be a little random motion here where we'll
try to drag it around, hoping that we'll bump onto a disk.
ALAN ALDA (NARRATION) It looked to me as if the helicopter was
flying too low to drag the magnet around the whole circle.
I found myself making an acute observation..
ALAN ALDA So the problem here is that you need to make the string
ROCK Maybe we need, yeah, high tech solution. (laughter) Make
the string a little bit shorter. Whoa, it got one. The robot
had finally got a disk-- but then it picked up another one--
and that's against the rules. But the Stanford team still
had plenty of time. For the Texas team, though, time was running
out-- and their tail-sitter was heading the wrong way.
Four minutes guys.
STUDENT 1 Think quickly.
ALAN ALDA What are you trying to come up with?
STUDENT 1 We're just trying to adjust the gyros as the instruments
ALAN ALDA (NARRATION) But the drift problem affecting the tailsitter
proved unfixable. At least this year, the Texas robot didn't
scatter itself across the field. The German team was also
coming down to the wire.
ALAN ALDA So you made it up.
ALAN ALDA You got up just barely. You have to be up off the ground
before you leave that square, huh?
ALAN ALDA (NARRATION) Sailing serenely-- and autonomously-- the
blimp headed in the right direction... Only to overshoot.
ALAN ALDA If it just gets a little calm air it might be able to
settle into that - oh no. Outside.
STUDENT OK. So we can put it again --
ALAN ALDA 45 seconds left. Watch out! Watch out!
ALAN ALDA (NARRATION) The blimp had begun its day battling the
ALAN ALDA 20 seconds.
You want to get it restarted.
ALAN ALDA (NARRATION) And it was the breeze that finally defeated
FINKE I think one could see that we could manage with a little
luck and with less wind.
ALAN ALDA Yeah. Congratulations.
FINKE Thank you.
ALAN ALDA (NARRATION) Another blimp was having similar problems.
But this one-- with a distinctly home-made look-- turned out
to be the work not of a college team but of students from
the Thomas Wooten High School in Rockville, Maryland.
ALAN ALDA When you have school to worry about, how much of your
day can you spend on this?
STUDENT Oh, we would spend until midnight a lot. We would
spend 5, 6 hours a night on it. And, I mean that bag, everything
here is home made. We didn't buy anything, you know, bought.
STUDENT Go that way.
STUDENT I'm going, I'm going.
ALAN ALDA The wind is too strong for you, huh?
STUDENT Yeah, too strong, too strong. Just a slight wind throws
everything off for the blimp at least. That's why a lot of
these college teams have helicopters.
ALAN ALDA Yeah.
STUDENT And you can see the other two blimps have the same
problems we do.
ALAN ALDA Yeah.
ALAN ALDA (NARRATION) Under direct radio control, the high school
blimp wasn't even trying to fly autonomously.
ALAN ALDA You're in, you're in.
STUDENT No, OK. Concentration people. It's not working Mr.
ALAN ALDA (NARRATION) But just by being here and flying, the Thomas
Wooten students have led the contest organizers to consider
a high school version of the contest in the future.
ALAN ALDA What do you think you've learned here?
STUDENT The biggest thing I've learned is that, you know,
even though we're a high school team we can overcome whatever
challenge we need to overcome. It's amazing. I came here thinking,
"Wow, we're out of our league." And coming and see that they
have the same problems we do, it, it's, it's kind of a relief,
ALAN ALDA Yeah, yeah. It gives you confidence.
ALAN ALDA (NARRATION) The high schoolers had devised from a cylinder
and magnet a clever device for picking up and dropping the
discs -- a system that made Stanford's method for snagging
discs look primitive.
STUDENT How much do we want to shorten the string?
CONWAY Oh, about that much.
STUDENT About half, about half a meter?
ALAN ALDA (NARRATION) But now that they'd taken my advice and shortened
their string, Stanford took off again.
ROCK Hands off.
ALAN ALDA Oh you've got it, you've got it, you've got it. (applause)
ROCK OK, let's not get another one. If we can just move it
to the center fence we can get points.
ALAN ALDA (NARRATION) The helicopter, all on its own, did everything
it could to complete its mission.
ROCK All right, that's it whew!
ALAN ALDA (NARRATION) But the one thing its designers didn't have
time to include was a way to drop the disk once it had reached
its target. Ironically, what they'd planned to use was a device
using a magnet and a cylinder.
ALAN ALDA Using that cylinder seems to be the way that the high
school team solved that problem too.
ROCK It's almost an identical solution to the high school
team; I was looking at that earlier. And they've got a real
neat little system and it's the same kind of an idea that
ALAN ALDA Is that as well as that's ever been done?
MICHELSON That's the best it's ever been done in the history
of the competition. And if they just had an intelligent device
to let go of the dog gone thing, they would have totally completed
ALAN ALDA (NARRATION) In the final scores, the Texas tailsitter
took third place, the Berlin blimp was second, and the Stanford
helicopter-- so close to completing the mission-- came in
first. Five years ago, the mission seemed impossible. Next
year it will probably be achieved. And in the future?
ALAN ALDA Do you think 20 years from now there will be some aerial
robot that will be working --
MICHELSON I think so, yes.
ALAN ALDA -- and out there doing something? What do you think it
will be doing?
MICHELSON It will probably be doing what we call D-cubed,
which is Dull, Dirty and Dangerous jobs. The dull jobs are
jobs where you've got to go out and inspect things for hours
on end. They're very expensive to put a man in a helicopter
to go look for beetle damage in pine trees.
ALAN ALDA Yeah.
MICHELSON But you can send one of these vehicles out and let
it fly all day long, taking data, looking for dead pine trees.
The dirty part has to do with going into places where you
don't want to send a man; say into a, an area like Three Mile
Island or Chernobyl to get air samples.
ALAN ALDA Or to rescue somebody.
MICHELSON Or to rescue someone. That's right. And you would
never want to do this with a manned vehicle because you'd
put two people in jeopardy then if it's a rescue mission.
So Dull, Dirty and Dangerous I think embodies the kind of
missions that we'll see unmanned aerial vehicles doing in
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