Interview: Paul MacCready
Engineer of the Century

When did you first get a sense of what you wanted to do in your career?

Paul MacCready: When I was twelve, I wanted to be a doctor, because my father was a doctor. I just assumed that I was going to be. Shortly after that, I got very involved in model airplanes and it became more obvious that it would have something to do with aviation, and maybe physics and engineering. But even when I was in graduate school, I didn't really know what I was going to get into and what happened was very different than what you could have predicted anyhow.

Many of us built model airplanes, but there was something in that that drew you to that, as a life's fascination. What do you think it was?

Paul MacCready: You could concoct a bunch of reasons but that doesn't mean that its necessarily so. So I have to guess at what made me interested in aviation.

I think one thing was that in high school I was always the smallest kid in the class by a good bit, and was not especially coordinated, and certainly not the athlete type, who enjoyed running around outside, and was socially kind of immature, not the comfortable leader, teenager type. And so, when I began getting into model airplanes, and getting into contests and creating new things, I probably got more psychological benefit from that than I would have from some of the other typical school things.

Without thinking about it, I probably found the models more appealing. And, of course, as I look back now I'm delighted that I had these defects or problems back then, and got into models which led to a lot of other things that have been very exciting, rather than just being a football jock, which I certainly would not be at this age.

I somehow got especially interested in a large variety of models. My father was very supportive and that helped, but he wasn't leading me, he was supporting. I found myself instinctively drawn to working on ornithopters, autogyros, helicopters, indoor models, outdoor models, hand-launch gliders, rubber power, gas power, just a big variety. I wasn't as good as some other modelers, but I don't think anybody had the breadth of experience that I had back then. There was something appealing about it, and in a few cases I set some records in some new category, which was fun. It was just plain enjoyable to do something that was new and different that hadn't been done before.

What other experiences or events do you think most influenced you growing up?

Paul MacCready: The culture I was in, the sort of schools I went to, the various people my family was involved with. We all worked hard, and had a good life. You tried to get good marks in school without knowing why you were trying to get good marks. That's just what everybody did. You look back and you're glad you paid that much attention in the schoolroom. It was just the culture of the people who were coming out of the depression era. Life was maybe a little simpler then. You worked hard to try and get some place.

So starting with that was quite comfortable. In the private high school that I went to, everybody who goes there almost automatically goes to Yale. I got a good education at Cal Tech afterwards. I still didn't quite know what I was getting the education for. It was just "that's what you do." Being in the right circumstances, having the privilege to be able to go to some of these things was very helpful.

It sounds like you didn't see a lot of limits on human potential.

Paul MacCready: If you want to move mountains, you just go move mountains. If you don't have a big enough shovel, you get some friends to help you. If you have the enthusiasm to charge ahead, you can do all sorts of things. Some things you can't do. You can't invent a perpetual motion machine. You've got to select your targets. But people can do so much more than they realize.

What is it that makes us often focus on the obstacles rather than the possibilities?

Paul MacCready: It's our whole lives, our education system, our parents, circumstances. You can get away from it by being put in circumstances where everybody else just doesn't even know the word "problems." Challenges they understand. Things aren't barriers. If there is a barrier or a stone wall, you walk around the end, you leap over it. You don't beat your head against it. I've gotten a good bit into the teaching of thinking skills. Thinking skills means many different things to people, but mostly it's an open way of receiving the outside world and being much more open in what you are doing, how you handle problems. You can hugely improve a persons thinking skill in just a few hours, because you haven't had it in school before. If somebody teaches you a few little tricks that can become habits, you are a different thinker, and it only takes a few hours.

You said some of the people you knew growing up were a fairly important influence on your thinking and your sense of what your own potential was.

Paul MacCready: Yes, they were. It wasn't teachers in school. I'm sure they did a good job, but I wasn't a responsive student. I didn't interact with them a lot. Irving Langmuir, a Nobel Prize winner in chemistry was one of the pioneers in weather modification, and he was very helpful to me. I just followed him around, interacting with him. A lot of enthusiasm rubbed off, a feeling of there are no barriers, you just charge ahead. It doesn't matter whether you know anything about that subject. He'd plunge into a new subject and ask lots of questions, make mistakes, and plod ahead. It didn't worry him whether he was right or wrong, as long as he was building toward something worthwhile.

When you were in school, was there a particular subject that you liked better than others?

Paul MacCready: The ones that were easiest. Physics and math were easy because they just involved principles and they were kind of fun, like games. History and English were very difficult, so I didn't enjoy them, but I did pay a lot of attention to them. I figured, I'm not good at them, so I should work a little harder.

As I look back, I realize I probably had some manifestations that would be called dyslexia now. Not a basket case but, certainly in some things, a short attention span. If I would start reading a paragraph of history, by the time I was to the second sentence my mind would be a thousand miles away. And even in physics classes, I would tend to daydream about other things, not getting so much good out of the class.

I still tend to jump between subjects in my mind. Also, if I write down 274, I say 274, I write down 274, and I look at it, and I've written 254, because I'm still mixing up a few numbers. There is some misconnection between one part of the brain and another part, or the motor system. Not enough to be at all troublesome, but it makes you realize how difficult it would be to get by in life if you had a bad case.

Having a brain that works a little differently than what best fits the school system, you learn to cope and emphasize the things -- You sort of do it the way that best suits you. I did most of my learning during the homework rather than the class period. A lot of dyslexics are very creative people. They have some real problems to overcome, and they figure out good ways of overcoming them. In fact, the jails are probably full of dyslexics who are very bright in figuring out how to do crime, which is what they are left with when they can't fit into the school system.

Do you think that's a shortcoming of the school system?

Paul MacCready: Yes, and of our whole culture. People without dyslexia seem like oddballs to me. When we were evolving into homo sapiens, 100,000 years ago in the savannas of Africa, why would the ability to look at little wiggly lines and curlicues on a flat sheet and interpret sounds and messages from them have anything to do with survival? I can understand how other things that dyslexics may be pretty good at -- the ability to see, run, reason, fight the lion, whatever -- all those talents provided survival and therefore evolutionary selection. The ability to read -- which is so much what our modern civilization is focused on, 'til we all get to be TV addicts -- seems sort of unnatural. But our whole school system and culture is built up around that. I think there may be a sort of mismatch between that, and what people really are.

You obviously worked very hard along the way. Do you think luck or happenstance play a fairly large role in what happens to someone in his or her life?

Paul MacCready: If you charge around and do a lot of things, you have more opportunity for luck. If you figure out exactly what you are going to do, and just go doggedly at that for three decades, you are going to miss a lot of boats. The world changes so rapidly now, what is important is evolving so quickly, that I think you better jump into new opportunities and new challenges. You may not do as well economically, but I think it's important.

Important for your own outlook on life?

Paul MacCready: For your contribution to the world, but also in keeping you alive. It's very awkward for people who were good students, and went into the aerospace industry because that was the best job offer for the engineer or the aerodynamicist. They get more specialized, they get high salaries with all the military-industrial complex procurement. A person can get narrower and narrower and more specialized, and end up sort of useless for the world, unfortunately. Suddenly there is a big cutback, and this person isn't that useful for anything else. Some of the very best things happen when people are specialists, but there is more virtue in adaptability now, because the world is changing so fast. It is not the simpler world it was 50 years ago.

That certainly argues for maintaining a breadth of interests and a breadth of knowledge.

Paul MacCready: Whatever you have been trained in, it's the wrong field for the most exciting, important subjects of 20 years from now. When you go to school, it is great to develop some skills and learn fundamentals that are common to any field you get into. There is a lot of very good training that engineers and scientists get, to deal with reality. They learn to be creative and have to figure out goals and solve problems. Sometimes, when they get into art or history or philosophy at some later time, they bring some talents to those fields that people who go through the ordinary training aren't as good at.

Do you often find that something you learned in an unrelated field takes you in a direction you would never have imagined, had you not stumbled onto it in a search for knowledge?

Paul MacCready: I'm lucky. I've been able to move from one field to another. At the right stage, that can be really exciting. Things are evolving so quickly now, in all fields of science, philosophy, history, everything else, ambling around from one field to another is especially important. I'm lucky that I've been able to do that. When you get into a new field, you don't have some position to protect. You can ask any dumb question, and learn an awful lot. Sometimes you bring something different to that field than the people who are already in it, so you can make some contribution.

What kind of books did you read when you were growing up?

Paul MacCready: I read the Oz stories, myths and fables. As a teenager, I remember Jerry Todd stories, who was kind of like a humorous Tom Swift. There were a lot of Big Little books, Flash Gordon and Tarzan, things like that. As I got older, some more serious books and novels, and now all kinds of books and there are great magazines that come in such great profusion, you can't possibly keep up with them all. The book that really got me going into something was Comstock's moth book. I got hugely involved, around the age of 10, in collecting butterflies and moths. I learned the scientific names of all the big butterflies and moths, and did a lot of collecting. At that age your mind is pretty fertile, and if you have a hobby you can devote yourself whole-heatedly to it. That was a good one, coaxing me to read, and be outside a lot.

Did that help create the kind of curiosity that would take you, later in life, into all sorts of new fields?

Paul MacCready: I think everybody is creative. When you're in the play pen, fiddling around with all sorts of things, you are creative. Certainly in the sandbox you are creative, playing around with toys or the boxes the toys come in, which often offer more creativity. Everybody is. The way you interact with people -- you are very creative in the way you manipulate adults when you're a youngster. You can figure out just how far to push them and so on. Then somehow you get into school and more standard parts of culture, and so much of this erodes with most people. But really, everybody is creative and -- put in the right circumstances, even if they haven't been what you call creative -- the creativity can be fanned into flame.

What led you into flying sail planes? You made models and so forth, but what led you in that direction, rather than in flying Cessnas and that sort of thing?

Paul MacCready: When you get into outdoor model airplane flying for duration, you learn about thermals and you hear a little bit about sail planes.

I remember a newsreel in, let's say, 1938, when I was 13 year old, that showed a sailplane flying over a slope at El Mirage. Just this big, graceful machine flying along -- it still sticks in my mind as an early memory. The newsreel also showed a crash a few minutes later, but that didn't bother me. No one was hurt. It was such a wonderful kind of flying. And I found that it was a wonderful, addicting hobby.

Its a very scientific sort of hobby, its not just like going out and rowing a boat. You get involved in the science of the vehicle, because the vehicle has to be efficient. You have to learn something about meteorology to figure out where the upcurrents are and how to make proper use of them. It doesn't matter what your background is, you become a scientist of sorts if you get involved actively in sailplaning.

It must be wonderful to have a hobby where you marry your passion and your technological and scientific interests.

Paul MacCready: That particular hobby was good because I was able to fly in contests, which are a lot of fun, but sort of demanding. I didn't do much flying in between times, because it was very inconvenient. But for contests, you could go to a foreign country for weeks at a time, and learn a lot about the country, meet a lot of people from all around the world, and do the flying. It was a very special hobby.

I don't think of myself as especially competitive, and I sometimes wonder about competitions and how they motivate people. I don't have a lot of answers, but the competitions are great things for coordinating people's interests. It doesn't matter whether there is a money prize, or just a trophy. People get together and do compete, and share, and it may not matter who wins. If you are in a contest, there is always some motivation towards trying to win, but the real value is just entering in the competition.

There are many people who would look at that and think that it is just one step away from sky diving. There is a great deal of danger and excitement in that. Did you think about it in that way?

Paul MacCready: I didn't do anything that I thought was dangerous. Danger is not the least bit appealing. It's just dumb. You should avoid it. When you are flying inside thunderstorms, you go to where some of the most vicious weather is, maybe in some hailstorm, into the hail-generating part of the cloud. Huge upcurrents and downcurrents and big turbulence. You can get into things that are a bit more intense than expected, and you may have to land in some giant wind, with big wind shear. You get a proper respect for weather, and you try to be very careful. But still, in various competitions, I found that by making a series of very safe decisions, I still ended up in an unsafe place. It didn't make me thrilled or excited. It just made me mad, and I resolved not to get in those circumstances again.

The last flight I had in competition, in the 1956 International contest in France that I won, I got in circumstances where whether I survived or didn't just was a flip of the coin. Whether the turbulence went that way, or that way. As I was down in a valley from which there was no way to get out, with huge turbulence just buffing, like a little chip of wood in a frothing surf.

I didn't like that. There are often many sail planes all on the same thermal, and people not watching out properly. I found other people willing to take many more chances than I would, and two sail planes would be willing to go on the same small cloud at the same time and things like that. I began figuring this really wasn't the sport for me. I did some dumber things after that, but never with the intention of it being dangerous.

You can find your thrills in other ways?

Paul MacCready: Yes. Too much to lose. Life is too pleasant.

As you look back, was there a moment you would identify as your big break?

Paul MacCready: The most exciting event was when it suddenly dawned on me that there was a sure-fire approach that would permit one to win the Kremer Prize, achieve the sustained control of human-powered flight. Winning the prize was nice, but that was just inevitable, once one had the idea. That was the important part. That was the sort of "A-ha!" moment. Many wonderful things have evolved as a consequence of that. Life would have been OK if that hadn't happened, but it launched me on a bunch of other areas, which my background did prepare me for, but I didn't know what they were.

You have now built, if I have the number correct, five planes that are powered either by human energy, or by solar energy. What is it that fascinates you about minimal or low-energy vehicles? What is it that got you so focused on that?

Paul MacCready: What was really fascinating about human-powered flight was the £50,000 prize for achieving it. That's the sole reason that I got into it. A subsequent project of human-powered flight was the Gossamer Albatross flight across the Channel. That was for £100,000. That was the glorious motive for doing that project. After that, the projects were done for somewhat more altruistic reasons. One thing led to another, and we couldn't have anticipated what happened. They all have tended to feature light-weight, pushing-the-frontier, low-power, electric power, solar power, human power and so on. There was a lot of random influence, but it all began because of prize money.

You had a particular economic incentive, a particular reason that you were interested in that prize money. What was it?

Paul MacCready: I had guaranteed a relative's loan at a bank for roughly $100,000 for him to start a company which didn't succeed, and he couldn't pay the money back, and as guarantor of the note, I was obligated to pay the money back. Because of some peculiar circumstances, I thought I had some liquid assets around, but they had evaporated while all this was going on. So I was stuck with the debt, which was rather annoying. There wasn't anything I could do about it. And, I didn't have any special plans on what to do, but I couldn't figure out how to handle it. But I was going on this vacation trip in the summer of 1976, having time to just day dream, let the mind dawdle around on what it wanted to think about. Nibble away on old memories, and new thoughts and making connections that I otherwise would not have made.

I did recall, with no special emphasis, this £50,000 prize that Henry Kremer had put up 17 years earlier. And then, one day I happened to notice that at that time the pound was worth just two dollars. Suddenly, this great light bulb just glowed over my head: the prize was $100,000, my debt was $100,000. There just may be some interesting connection between these two. So my interest in human-powered flight zoomed up to high level, and I fussed away at it, and eventually it worked.

What is the Kremer prize? How was it established.

Paul MacCready: In the history of aviation, I think there was always an interest in human-powered flight. Leonardo da Vinci drew a man flying in machine. You think of a bird and you wonder, "Can man do that?" Then, when the Wright brothers began engine-powered flight, people realized that human-powered flight is really pretty impractical. Humans put out about a third of a horsepower, but engines can put out 10 horsepower, 100 horsepower, 1,000 horsepower. Eventually airplanes achieved all sort of great goals with those engines, so human-powered flight just got forgotten. But as an old goal, it still lingered in people's minds. There were some tiny prizes put up for it in the '30s which weren't won. Then a group in England called the Manpowered Aircraft Group began working on it on a very low level, hobby basis. One of the stalwarts in that group ran a company owned by the British industrialist Henry Kremer. They were having a three-martini lunch, and Kremer asked how it was going. It wasn't going very well. How can you get it moving? Maybe a prize would be a good idea. I'll put up a prize.

So this was not just another ordinary challenge. I think it had great value. The significant prize produced our Gossamer Condor, without which there would not have been a Gossamer Albatross, without which there would not have been the Solar Challenger, or the Pterodactyl. Without all of these there wouldn't have been the Sunraycer, the solar-powered car that won the race across Australia in '87. Without that, there would not have been the Impact, a battery-powered car that is now going into mass production. As you look back, you realize that was a pretty important lunch that took place many decades ago.

It's fascinating that the challenge that Kremer thought about, and the prize money that went with it, coincided with your financial need. What was the next step?

Paul MacCready: With my particular skills, strengths, and weaknesses, it was almost as though the Kremer prize was designed for me. There wasn't anybody in the world as well-situated to handle it. I had knowledge of aerodynamics, but no knowledge of structure, so I could deal more flexibly with new methods. Living in southern California with all the aerospace industries around, if you need some tubing, you just go buy it. If you need it chemically milled, you take it somewhere and they chemically mill it. You couldn't do this in some other state, or some other country. And here you can get a good airport, and an empty hangar, if you hunt around for it. The weather is gentle. It seemed like the perfect spot to win that prize.

Chances have combined to create your interest, and the perfect spot, to meet this challenge. Once all of those things were in place, what was the next step?

Paul MacCready: Every time I came up with an idea, it turned out it was it was the same way the teams in England had been doing it -- elegant groups that made sophisticated aircraft and didn't come close to winning the prize. That proved that those approaches were not very good. Plus I couldn't aspire to make such complex, elegant aircraft as they had made.

So I gave up on it, and went off and did other things. This is a fairly acknowledged way of coming up with inventions. You get yourself all full of details, still can't figure out how to overcome the problems, and you give up and then, suddenly, an idea pops into your mind, or a dream, or something else you are doing, shows you a way to handle it that you would never have gotten by sitting in your office and grinding along in a good linear fashion. It requires getting away, looking at it more dispassionately, or not even looking at it.

I was on vacation, and I realized you could figure out the flight speed and the turning radius of birds soaring in circles -- like you see a hawk, or a turkey vulture do -- by noting the time it takes to do a turn and estimating the bank angle. Just a fun little scientific hobby. You can do it with essentially no tools. Just your wrist watch, and estimating the bank angle. From those two numbers you can calculate the flight speed and turning radius. You have to write a formula, and maybe use a little calculator for it.

We began to be more interested in how one bird compares with another, and how does this compare with a hang glider. Did it fly at the same turn radius? What about sail planes? How much power does each take? What about the power per pound?

I was doing the scaling laws for all of these different flight devices, natural and artificial, in my mind. The scaling laws are pretty simple. And while working on that, I thought back about human-powered flight and realized, why yes, there was a very simple, straightforward way of doing it. Which was merely, you can take any airplane, conceptually, keep the size the same -- I mean, keep the weight the same -- but let the size just get bigger and bigger and bigger in all dimensions, and the power goes down and, conceptually, you can make it big enough so it can get by on the tiny power that a person puts out.

If you take a hang glider with a 30-foot span, keep the weight around 70 pounds, and swell it up to a 90-foot span, the power you need goes down to one third of what it was, about .4 horsepower, which a good athlete, can put out for some number of minutes. So you didn't need an elegant sailplane-like aircraft. You could have an ugly, dirty-looking, hang glider-type plane. Quick to build. As long as you made it giant, without the weight going up.

That was the basic idea. There is one other idea which is essential, which was how do you make something that big without the weight going up? There, the gimmick was that you did not need the structural safety margin that you need in a regular hang glider, which is going to fly at high altitudes, so if it breaks somebody is going to get hurt. This was only going to fly at ten feet altitude at ten miles an hour. If it broke, who cared? Nobody would get hurt. But also, you could have it just on the very edge of breaking. No safety margin at all. Instead of cables, you use thin piano wire as a structural element. With that idea, and the basic idea of large and light, the problem was solved. There would be a bunch of grunt work, engineering, to actually win the prize, but the idea that assured the prize could be won was in my possession.

All you needed was just the minimal amount of structure and energy to accomplish the goal that had been set.

Paul MacCready: Yes. It had to be larger and lighter than any plane had been made until then. It ended up with a 96-foot span and 55 pounds, occasionally up to 70 pounds, which is pretty light. Unprecedented in the way people have made airplanes.

You talk about the 96-foot wing span of the Gossamer Condor. How does that compare with the commercial aircraft most people are familiar with?

Paul MacCready: I forget. I think the DC-9 and the 727 are around that wing span. The 747 would have a 150-foot span, I think. So its smaller than a jumbo jet, but its actually larger than some of the smaller transports that you see in the sky. But a lot lighter, and a lot slower, and it doesn't carry many people, and the people it carries have to work pretty hard.

And there is no drink service.

Paul MacCready: Well, on the cross-channel flight, there was drink service. There was a supply of water for the struggling human engine.

When you started building the Gossamer Condor, did it turn out to be a bigger task than you anticipated?

Paul MacCready: Every task I get involved in is a lot bigger than I expect. People who work with me double the time estimates, or increase them by a factor of ten. The latter are usually more correct. We were entering such a new realm of flight you couldn't predict what was going on. Looking back, we did it just right, as quickly as we could. After some early tests and models and a bunch of calculations, we built a first version without even putting a propeller on it, just to see if it would fly, and about how much power it took to keep it up. Then we added a propeller and did a lot of tests with it. It was pretty crummy, very crude, bad stability and control and so on. But because we could rush it out and do tests with it, we began getting good insights about all its difficulties.

Wasn't there one problem that you were able to solve by going back to something that the Wright brothers had learned.

Paul MacCready: We went back to what birds have been doing for a hundred million years. Because the flight was so slow, turns were fairly large, I thought you'd have a wing that always had the same shape, and you could gently get around the turn. But we were having huge problems with the turn and with other aspects of stability and control. We finally did some calculations and realized the huge increase of angle, and the tack you get on one wing versus the other wing. In order to maintain lift, you have to change the angle of the wing. You just plain have to twist the wing, and it suddenly began working pretty well. I should have figured that out ahead of time, and incorporated it into the first vehicle, but because I have mental blinders like everybody else, I went off on what I thought was a simpler approach. I tried to do everything on this project as simply as possible, assuming that the simple answer would work. You knew it wouldn't always, but that saves you a lot of time, so when you get to a troublesome thing, you can spend some time with it.

Then, we took a couple of slabs of balsa wood and made a little model in about an hour, and pushed it around in a swimming pool. That gave us some final insights about what our computer programs were trying tell us. The computer programs were correct, but they didn't give us any insight. This swimming pool event gave us the insight to complete all the stability and control problems. We came up with a final version and it worked.

Tell me about the day you had your first successful flight with the Gossamer Condor.

Paul MacCready: We were getting longer flights each day, cleaning it up, tightening the mylar, getting things that don't ripple as much, and getting the pilot more accustomed to it. To win the prize, we had to do a figure-eight flight around pylons half a mile apart. He did a flight that almost completed the one-mile figure-eight. You have to go over a ten-foot marker, at the very beginning and at the very end. We had done a flight of almost eight minutes, but couldn't get over that last hurdle. It was pretty obvious that the next time, if the weather was right, it was going to work. We got a forecast of appropriate weather, and we got the official observer out. It's a two and a half hour drive from here to get to the airport, so we went out the previous night. We got everything together, and the flight succeeded -- just barely.

How did you feel at that moment?

Paul MacCready: I was certainly elated, but I knew we were going to win some time. The real elation was when the idea occurred to me about a year earlier. But this was a great sense of relief, because a project like this costs money, it costs time, you have to coordinate people, and there are never enough resources, never enough people, the weather isn't right, et cetera. There was a lot of pressure, and suddenly the pressure is off. So it was a relief and a great celebration, of course. A few days later, everybody got to fly the plane. A bunch of us been test pilots during the development, but now everybody on the project got to fly it. And all their friends and relatives, and little kids and old ladies. You don't need to be a pilot or an athlete to fly it for a short time. It was fun.

So it was like giving pony rides on the Gossamer Condor.

Paul MacCready: Yes. It was very special.

How long was it before you started thinking about the next project?

Paul MacCready: This prize of Henry Kremer's that had stood for 18 years no longer existed, so about four months later, he put up a new prize for a flight across the English Channel, which is a 22-mile flight across a dangerous body of water. I think he expected it to take another 18 years for somebody to do that, because it was so much longer than the one-mile flight. But we just cleaned up the Condor, gave it a more accurately contoured wing, many more ribs, and so on. We focused on structure and didn't pay any new attention to aerodynamics, because that had all been solved in the previous one. This new plane, which we would call the Gossamer Albatross, could get by on maybe a third less power. A bicyclist can put out a little less power for a much longer period of time, so Brian Allen, our pilot, could fly this new plane for hours.

We were using carbon fiber composite tubes instead of aluminum, lightweight foam ribs, a lot of sort of space age materials to make a better vehicle. It flew right from the beginning, doing just what it should. We had the usual accidents and control problems, but it was obvious this was capable of winning the prize. It was also obvious that this was going to be a big project, to build back-up airplanes, to test them, get them to break in controlled circumstances, rather than out over the channel, and get them all to England, and wait around for weather, and do more tests there, and rent boats and so on. So we sought sponsorship. The DuPont Company whose materials we were using a good bit of, agreed to sponsor it. It was very surprising that they said yes at first, on a very peculiar human-powered airplane project. They said no a couple of times before they finally agreed.

Even though you had done all this researching and testing, how exciting was the actual flight of the Gossamer Albatross over the Channel? Both for you, keeping track of what was going on, and for the pilot?

Paul MacCready: The actual event was one of the most exciting things I'll ever live through, or that any of the people involved in it will live through. That doesn't mean it's something we'd want to go do again. The pilot was tired, but the 100 other people in boats going along with him, trying to use psychokinesis to lift him up mentally, were also exhausted by the time the thing was over. The really big pressure was organizing this thing. You had to predict the previous day, by three o'clock, whether you were going to do a flight the next day. None of the weather forecasts ever agreed with the weather that subsequently materialized. It's a very difficult area to get good weather forecasts. I had a broken foot at the time, with a cast on, and I had to ride a bike over from the airport to a pay phone to get the weather forecasts, and then decide whether or not to turn on the whole project. Once the project was turned on, about 100 people, all the team, the DuPont people, journalist types, were converging from all over Europe. It was like running D-Day out of a telephone booth. Plus the usual pressure: we were running out of money and the weather wasn't right. Finally, we thought, "OK, let's try it." There was really zero chance of it working right the first time, so first plane was considered sort of a sacrificial plane. We didn't know what was going to go wrong, but we knew that any one of a hundred things could go wrong. We assembled the plane on an acre of concrete called the Warren, where one of the early tunnels was being dug from England to France, just in the right place for us.

I heard the wheel on the front of this was a toy wheel? Was it actually from a toy?

Paul MacCready: Yes, those are the lightest. You can't get any non-toy wheels that are down in the two ounce three ounce category. This was about five inches in diameter. It was only going to be used once on the flight, for a few seconds on take off. The rest of the time it was just dead weight. So you don't want it good, reliable, just strong enough to handle that. We found that for little toy trucks you can find such wheels, so that's what we used. This whole project, and the previous Gossamer Albatross project, was to win the prize. It wasn't to have fun, it wasn't to make a museum piece, it wasn't to make something that was ever going to fly a second flight. It was just to win the prize. And, the Gossamer Condor, we never even drew plans, until after the prize was won. You didn't need plans for the way we were doing it. We did use computers for some things, but there were no plans drawn. And its rare that you have a project that is so simple. One goal, and you can focus on that. People tend to formalize things more, and they do more drawings and make parts better than they need to be. We knew exactly what we were trying to do, and we compromised right to the very limit on every little part. So if a toy wheel worked, great.

So then, you got the Gossamer Albatross up in the air, and what happened next? Did everything go as planned?

Paul MacCready: It was up in the air and everything was going fine. There was radio communication both ways. I was in a boat about 1,500 feet in front of the plane navigating with radar, and figuring out where all the boats in the channel were going to be by the time we reached them, because you couldn't cross in front of one of the big super tankers. If you crashed, they can't turn, and you can't be within two miles behind them, because they leave turbulence in the air that would be too much for the plane. So you have to know where you are going to be 20 minutes ahead of time, where they are going to be, and make little variations in the course. The whole thing was quite a strain.

We felt that Brian could only keep the plane up for two hours. Prior tests had shown his stamina at the amount of power the plane required. So we only gave him enough water to avoid dehydration for two hours. Any extra water would have added weight, and then he couldn't even have lasted two hours. Unfortunately, a head wind cropped up and, after two hours, he was still nowhere near the French coast. He was all out of water, and the increased turbulence in the air made the power required a little bit higher for the plane. Finally, he had to give up and signal for a tow. A little rubber boat with several people in it, went around under him with a fishing pole, and was trying to snag a line on a little ring on the plane, to tow it to one coast or the other. But during this maneuvering, he had to move up higher, and he found that the air was a lot calmer up there, and it took a little less power. Even though they were trying to catch the plane all the time, he kept dodging. The radio wasn't working, but he signaled that he didn't want to be hooked up, and he decided to continue for five more minutes and give it a try. The five minutes became ten, became 15, became 20. Some of the time he was down low.

For a while he was down really just six inches above the water, and the changing winds and somehow he struggled along as his left leg cramped from the dehydration. He pedaled mostly with his right. Then his right leg would cramp, and he would pedal mostly with his left. Towards the end both legs were cramped, but he somehow got that last little bit. And there was extra turbulence that was almost beyond the capability of the plane to handle its controls, just in that last bit, 50 meters off shore. But finally he made it, and it was almost a three-hour flight. Beyond all odds, just impossible for human stamina to have kept going that long, but he did.

If it had been high tide, I think he wouldn't have made it, because we would have had to go an extra hundred meters to reach the shore. It was that close. He had worked for the last several months before the flight with a full-time exercise physiologist -- Professor Joe Mastropaolo, who helped him train to build up his stamina. He was a good bicyclist, but he hadn't been doing Olympic training. He worked at it very hard, and Mastropaolo, I think, gave him the real spirit, the attitude that you just don't quit. It doesn't matter how impossible, how painful. If you are conscious, you are still pedaling. Somehow this sunk into Brian. What he did is beyond reasonable human stamina. I've never seen anything like it. So, another day of great relief. This pressure was over. We were pretty sure we would succeed some time, but to have it work the first time was remarkable.

How did old Kremer take this, when you knocked off the second prize, on your way to the third one?

Paul MacCready: He really wanted a Britisher to win the first prize. There was a British team, sort of working towards the second prize. I think maybe he thought that prize would be just right for the British team, but they didn't come close. I think they were annoyed that an American won the next one. They were also annoyed DuPont was sponsoring it. It looked like this was a big corporation project. Actually, DuPont didn't sponsor the development of the plane. They said, do the project your own way and they'd take care of the major expenses.

There was another Kremer prize of about £10,000 -- around $15,000 -- to duplicate our first Gossamer Condor flight. A couple of high school kids could have just copied the Condor, and built it with $500 of parts, and won that prize in England, but nobody did. It's kind of hard to figure out. But people in England were most cooperative. We got help throughout. People didn't seem to care that we were Yanks from overseas. As soon as we landed, the hangar that we had been intending to use fell through, and in just that day, we were able to get the Manston RAF base to provide a hangar, which they cleaned out. It was just big enough for us to set up operations in. A lot of people cooperated like that. They were delighted to see the prize won. That was one of the reasons that we were delighted to have the plane go to the science museum in London for a while. I gave it to the Smithsonian here, but they loaned it to the science museum in London.

In this same time period, you also starting building low-energy planes that flew on solar power.

Paul MacCready: The Gossamer Albatross project was a grabber on television, because it was a very exciting thing. There was a good movie done on it that showed some of the excitement. So, when we went to DuPont with the idea of a solar-powered airplane, they said yes. They figured if I said it could be done, then it could be done. They were going to handle expenses, there was no prize. The prize was somehow getting the man on the street, the government administrator, and so on, to have a little better appreciation for what solar cells can do. They are an important part of our energy future, and they will be one of the things that helps wean us away from this addiction to foreign oil which we now have.

Was it a lot easier to design the solar-powered aircraft?

Paul MacCready: Nothing is easy. First we made the Gossamer Penguin, which was a leftover human-powered airplane from the cross-channel project. Three quarters the size of the Gossamer Albatross. We happened to have a small panel's worth of solar cells at the beginning of the project, and we put those on. We just wanted to get our hands dirty, learning about the solar cells, how you glue them on, and how you wire them up, the problems of overheating the little electric motor, and so on. We put this panel up over the top of the airplane. It provided very little power, 400 watts or something.

We needed very lightweight pilots, so we used my son Marshall, who was only 13, as the pilot, because he only weighed 80 pounds. This plane was so different than a regular airplane, that it didn't give you any special advantage to have regular airplane training. Training in skateboards and unicycles is really good training for this. He flew the plane very well. Adapted quickly, and went through a lot of test flights. One very dramatic crash, but like all our crashes, it's low and slow (15 miles an hour in this case), the pilot wears a helmet, and nobody got hurt. No worse than you would in a small bicycle accident. He did the first flight where any human has climbed on the power of sunbeams. For publicity purposes, we had to show it in a long flight for the media at Edward's Air Force Base. But they weren't interested in having a 13 year-old kid without a license flying out of there.

The goal of these projects was really media. That's what the money was being paid for. So having to spend extra weeks on special flights is not a distraction from our project, it is part of our project. Some of the engineers just wanted to do the airplane, but after a while they realized this is all part of the program. Handling the media right is just as important as a better airfoil. The more people hear about it, the more they understand about solar cells and lightweight construction.

Flying an airplane on solar power doesn't really make sense. You can do it as a stunt or a symbol, but you're not going to have solar-powered airliners. The Solar Challenger was a very elegantly designed, developed airplane. It had a 48-foot span, weighed about 100 pounds of airplane structure, and about 100 pounds of solar cells and motor and wiring and so on, a little over 200 pounds total. The only way to get it to fly properly was to use a very lightweight pilot. We used either a 95-pound woman, or a 125-pound man, because that's the easiest way to save weight. It would just barely take off on the sun power that you get near the ground, where there is usually a little haze. You'd get about 1500 watts of solar energy to make it take off. It would kind of stagger into the air at about 19 miles an hour. But the higher it got, the stronger the sunshine is. The cooler the solar cells get, the more power it gets, so it flies better and better. It finally did the flight for which it was intended, Paris to the St. Manston RAF base in England, 163 miles at 11,000 feet. Most of the flight at that altitude was at about 40 miles per hour. So it did its job and was shown around at various exhibits and then it became a museum piece, like some of our other vehicles.

You've used solar power for planes and for cars, but does this have a broader commercial application? Will this become part of our lives?

Paul MacCready: Looking back over various unusual vehicles, there usually isn't a direct application of that vehicle. But now, when we are interested in energy conservation, some of those ideas are really important.

The simplest analogy I can think of is Lindbergh's flight across the Atlantic in 1927, which was really a pretty bum airplane. Well tailored for that purpose, but you couldn't see ahead of you, it was unstable. There was no reason ever to make another one. It was good for just that one flight. So here is an impractical airplane. It didn't help aviation engineering, and yet it changed the world, because it did that flight and, mixed with Lindbergh's personality, it was just the right moment. It was the catalyst that got us into being a real aviation country.

Some things that followed stimulated commercial airline transport, which has shrunk the world by a factor of 10 in size. So if you ask, "Was Lindbergh's flight in that plane valuable to help engineering?" No. To change the world, yes. It was certainly the most important invention in 1927. Some other inventions -- a better bearing, a better egg beater and so on -- may have made people more money right then, but changing the way people think is much more important than some little gadget you can make money on.

Did you see the Solar Challenger in the same way that you look back on Lindbergh's flight? That it had a certain symbolic importance aside from whatever interest it may have generated scientifically? You suggest it wasn't something that was likely to be commercially applicable, but that it did have some sort of symbolic significance to the public.

Paul MacCready: Just the fact that you can fly on the power of sunbeams is pretty remarkable. People think differently when they realize that. It's a catalyst for thinking. It just gets people to think a little more deeply, and a little more openly about alternative energy options.

You think about that a great deal these days.

Paul MacCready: Energy options? Yes.

Energy is one part of the whole problem. There are too many people and too much consumption, and not enough earth. We could get by with it in the past, but population has tripled since I was born, and there is more energy materials per capita being used now, and species are being wiped out. The latest number I saw is that one species is disappearing every four minutes because of man. We are facing a very different ball game. You can't extrapolate it from the past. Anything that makes it so we can get along on this limited world is better. Doing more with less is part of it, and somehow getting off our energy jag or addiction is important. You can do so many things with so much less energy that we now use. Now regular airliners, especially modern ones, are really designed brilliantly. They're made for efficiency. Nobody cares what they look like on the outside, but they are made to do their job. The aerodynamics is elegant, the structure is elegant, and they are really fine. Cars, on the other hand, are designed for a very different purpose. Styling is important, inexpensive mass-production is important, safety, operation by unskilled people, and you like peppy performance. When you do all that, they consume a lot of power. There aren't any airplane aerodynamicists involved in their design, although there are good aerodynamicists mixed in with the stylists. But look at the underside of any car. It sees the air just as much as the top-side sees it, but you realize how little attention is paid to smooth aerodynamics of cars. There sort of shouldn't be, gasoline was so cheap.

Many people have looked at solar power as such a promising technology. Why haven't we done more with it?

Paul MacCready: The biggest reason why we haven't done more with all sorts of alternative energies is that the existing energies we have are so wonderful. Oil is so relatively inexpensive. Not when you look at all its real costs, but in some ways it is. And natural gas is good. And nuclear power plants you already have are relatively inexpensive. Hydropower is pretty good. But we don't really have more nuclear power -- there are a lot of troubles with it -- and you can't get much more hydro power, so those are limited. Coal has a lot of trouble associated with it, but these are all somewhat inexpensive. All the economically viable alternatives were worked on for economic reasons in the past. Now, when you try and find some new thing that maybe doesn't have as much pollution, or is replenishable so you're never going to run out, you find that it is not as cheap as these others that are more limited in their future and have some negatives on pollution, about them. Unfortunately, all the things people have tried are more expensive. Solar cells were very expensive and have steadily come down in price. In the best circumstances, they can almost compete with certain of the oil burning power plants. Wind power is the same. It's been expensive, and we had subsidies for it.

When you took the solar power efforts you'd made in the air and took them to the ground, were there any major difference that you had to compensate for? Was there something that was fundamentally different about doing it on the ground than in the air?

Paul MacCready: Nothing fundamentally different. The Sunraycer is a very aerodynamic vehicle, made with airplane composite construction techniques. Its very lightweight tubular structure and solar cells were rather similar. It has an electric motor and so on. But still, it had a very different purpose, so we did a very different design. That project when General Motors heard about the solar-powered race across Australia. They thought this would be fun to enter, because they had recently acquired Hughes Aircraft, which makes solar cells. They thought a challenge like this would help the outside world appreciate that they were high technology, GM and Hughes. It was an interesting challenge for their engineers, and they wanted to get back into competition more, and they thought it would be especially good for education. The vehicle would be of interest to youngsters, kind of like dinosaurs, but would get young people turned on to engineering and science. So maybe more of the best and brightest would become scientists and engineers, instead of lawyers and MBA's, which maybe the world doesn't need more of. They wanted to do it, but didn't really know if they could.

We were able to get a lot of things going in parallel, and have a very quick project, because we knew the various aspects that had to go into it. There were only eight months from the start of the project to the race, but we were able to handle it and even have 4,000 miles of testing on the car before it started the race, to be sure of its reliability.

That car, while it demonstrated some of the benefits of solar power and its applications, as did solar-powered aircraft, sounds like it was more of a scientific curiosity than something that really had widespread application and potential.

Paul MacCready: Yes. I don't think there's any reason to have solar-powered cars in the future. That car did have a small battery in it, but it started with the battery filled, and finished the project with the battery. Still, it was able to use the battery when there were clouds in the later afternoon.

So, if you have a battery-powered car, it doesn't hurt to put on solar cells, you get a little help. But a real solar-powered car doesn't make much sense. But this was a nice stepping stone that got a lot of people thinking about it. If not for the great success of the Sunraycer, we probably would not have the Impact car project, which a battery-powered car with no solar cells.

We led the Impact development team for General Motors. It's a small, jazzy-looking, two-person car, but its got almost 900 pounds of battery in it. Regular lanacid cells, but carefully tailored to the purposes of this vehicle. In ordinary use, you would plug it into the wall socket when you get home at night, and the battery would be fully charged the next morning. If you want to plug it into a higher power circuit, you can charge it much more quickly than that. Once charged, it can accelerate from zero to 60 in eight seconds. We limit it electronically to 75 miles an hour, but it would go way over 100 if you wanted it to. We don't know any reason for it to. The range, in either the urban cycle or the highway cycle starts at 120 miles, but when the battery gets a little worn down, you may not be able to get quite as much. If you want to use the air conditioner a lot, you won't go as far. But for most commuting tasks, that's enough to handle things.

In terms of timing, it works out perfectly, because the time of day when power demand drops off is exactly when you would be charging your car.

Paul MacCready: Yes. But if you do a long trip in the middle of the day, you could recharge while you're having lunch and get a bit more distance. In the long run, I think we'll see cars like the electric Impact, with a little auxiliary power unit which converts chemical energy -- gasoline, hydrogen, compressed natural gas, propane, whatever -- to electricity by a little reciprocating engine, or a gas turbine or fuel cell. There are a lot of different candidate devices being looked at now. You can operate fully electric some of the time, but if you really want to go to Phoenix from Los Angeles, you generate your electricity on board, but you do it with great efficiency, because the engine that's generating electricity only has to operate one power setting, one rpm, and it can convert the fuel very efficiently to electricity, and do it with very low air pollution.

So you could have a gasoline engine to fuel the batteries, which then fuel the car. But the advantage is, you wouldn't have the deceleration and acceleration that is so wasteful of energy.

Paul MacCready: There are a lot of advantages. In city traffic, where you are putting on the brakes all the time, you're just throwing away energy. But with an electric car, you get that energy back, because they use regenerative braking. Instead of heating the brake linings, you shove electricity back into the battery. Now one big feature of the electric car is that the battery is such a poor source of energy compared to gasoline. You only get one percent as much energy out of a lanacid cell system as you get out of the same weight of gasoline. It is a factor-of-100 hit you're taking. The only reason it works is because you make the vehicle superbly efficient. That's why it hasn't been done before. It took the concept of efficiency honed through the human-powered airplanes and the Sunraycer to get the efficiency that makes the Impact feasible. Once you've done that, you can apply that efficiency to other vehicles, even gasoline vehicles, and consume much less gasoline. If you wanted to use compressed natural gas now, you'd need a big, heavy tank. But if you don't need as much energy, you can get by on a little tank. Efficiency has all sorts of advantages in making things feasible and cutting down pollution.

Are we about to make a major technological shift, in the way we get from here to there? Are we looking at a vastly different future than our recent past?

Paul MacCready: In a while, gasoline is going to be very expensive. I don't when, but its a vanishing resource, and its sources are tangled up with some very unfortunate political, military problems. In the United States, we are going to run out of our supply fairly soon, we are going to be completely dependent on others. We are probably going to start recognizing the real costs of it, not just what it costs to ship it here and put it in your car. It's going to be expensive, and we are not going to be using it in cars after a while. Certainly your grandchildren aren't going to be driving cars using gasoline. What they are going to be using on airliners, I don't know. I don't know a really practical substitute. But there are a lot of substitutes you can make for surface transportation. Surface transportation problems are all mingled with traffic problems too. There are technological solutions to get by on less energy and put out less pollution. I don't know the technological problems to handle the traffic. Too many people and not enough world. I think telecommunications are going to get much greater use as time goes on because travel, as in the Los Angeles area, is just going to be so awkward.

If you were talking to someone who is now starting in college, trying to figure out what area to go into, where the horizons of science will be, where the fascinating challenges will be, where would you point them?

Paul MacCready: I'd probably go into education. I wouldn't have said that years ago, but there are such huge things you can do in education. So much is done so poorly. Not because there aren't dedicated people, but a lot of new ideas are emerging and they are hard to inject into a system with a lot of inertia. Right now, teachers don't get much respect or much money. I think that's going to change as they get recognized as being so important. It's a very satisfying job. I think teaching, especially to youngsters in second grade, seventh grade, fifth grade, around that, is of absolute tremendous importance. These are the brightest minds. They haven't been beaten down by being narrowed, and they are open to all sorts of things. If you can help the opening process, that's very good.

The other subject to get into is the human mind, the most potent thing in the world. There is nothing more important. Soon, from your computer terminal, you will be able to access almost any book, any drawing, anything around the world. You will be able, through telecommunications, to talk to anybody, anyplace. You will be able to talk their language through little translators. Anybody, anyplace. It's beyond the comprehension of people who are around now, but we may be able to couple your brain to a computer, not by voice, sound, or punching buttons, but by things implanted in your brain. It's conceivable. Even the definition of what's a human is going to get more fuzzy. Computers are now sort of insidiously taking over and becoming more our masters than our servants, more than we realize. I happen to think that the surviving intelligent life form on Earth is going to be silicon-based, not carbon-based. Computers are going to take over. They are going to be brighter than people in the not-too-distant future. We will be pets for a while, after that... I don't know.

I know that you have expressed a great concern about the balance between technology and nature. Have we addressed that, or is there something more?

Paul MacCready: Man has basically won the war against nature. That's the bad news. We may wish he hadn't.

If you were a galactic explorer, coming from some distant galaxy, and you looked in at the earth, and tried to write it up and characterize. "What are humans? What are they like?" The easiest analogy that you have is a cancer. A cancer just grows like that. From the standpoint of the cancer, it's great. More cancer cells all the time. From the standpoint of the other cells that they are crowding out, it's the pits. And of course, after a while, they kill their host, which is bad for the cancer cells as well as the other cells. And that's what we are on the road to.

I know you're skeptical about technology, but do you really see this danger in the not-too-distant future that this process is going to start unfolding, and....

Paul MacCready: Man has become God. We used to think we were just this little thing, at the mercy of circumstances, lightning, the big world, whatever. Now, we can control things. We can wipe out all the other species. We can do genetic engineering and create new species, and just do things that were beyond comprehension before, and turn the world into whatever we want. I don't think humans have the brains, the wisdom, to be very good at this, because that's not the way they were brought up. They've got all these huge tools, but they're like a two year-old with a .45 automatic, who doesn't know what to do with it. What you'd like is not to have as many automatics around, and get that two year-old a little brighter.

But it's not inevitable. Man is an awfully bright creature, with a lot of creativity, and a strong interest in survival. So things may work out. There are a lot of serious efforts, like the Biosphere II project in Arizona. It was a very exciting experiment.

I alternate between pessimism and optimism, and I've found the best pessimism summary comes from the great philosopher, Woody Allen, who said, "Civilization is at a crossroads. One road leads to misery and devastation, the other to total destruction. We must choose wisely." And there is a lot more to that statement than you might think.

Thank you very much. It's been a pleasure and a privilege.

Thank you.