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Original Issue


With a little help from the sun, Paul MacCready's solar-powered airplane heads toward the ozone

On a bright blue day in December the Solar Challenger, the world's most expensive dirt-cheap airplane, took off from the Marana Air Park on the outskirts of Tucson. After circling the strip five times to gain altitude, the pilot of the Solar Challenger, a pert, petite schoolmarm named Janice Brown who holds commercial, instrument and glider ratings, headed across the cotton fields, arroyos and cactus-pocked desert. With the large propeller of her plane whirring slowly, making barely more sound than the beating wings of a goose, Brown flew for 22 minutes. In that time she reached an altitude of 500 feet and traveled slightly more than six miles. In so doing, she had in effect brought the history of aviation full circle, back to the legendary Icarus. It was because of the sun that Icarus crashed in a mess of melted wax and feathers. It was the power of the same sun that lifted the Solar Challenger and kept it flying, without any sweat on Brown's part, or a drop of gas, or any other source of power.

Compared to the super aircraft of the red-hot present, the Solar Challenger is not much for looks. Because of its big propeller, its broad wing and its stabilizers affixed to a thin boom, it resembles the rubber-band-powered "stick" model planes that kids build. The tough gossamer stuff of which it is made—Mylar, Kevlar, Delrin, Lucite, Teflon, Nomex, carbon fiber and piano wire—does cost a bit, but because the plane, without the 98-pound Brown aboard, weighs only 193 pounds, it didn't use much of anything. Structurally speaking, it's a bargain-basement item.

Its power plant—there's the rub. The propeller of the Challenger is driven by an electric motor, which, although the size and shape of a can of spray deodorant, costs $500. The 16,128 voltaic cells spread across the upper wing and horizontal stabilizer to convert sunlight into electricity are valued at $130,000.

Because the power derived from this bank of converters isn't enough to drive a large chain saw, the Challenger isn't a practical machine. It came to be largely because of the enthusiasm it generated in the Du Pont Company of Delaware and in the National Aeronautics and Space Administration. Du Pont contributed $400,000 to the project, in part because the Challenger is made largely of synthetics the company produces. NASA lent the costly solar cells after sticking its own neck out to borrow them from the Air Force. Neither Du Pont nor NASA makes a habit of contributing lavishly to far-out ventures, but both could easily do so in this case, reassured by the fact that the designer of the Challenger was Dr. Paul MacCready, a Pasadena physicist whose reputation for getting improbable machines to fly recently earned him the title Inventor of the Year.

The 55-year-old MacCready has spent his life studying and using the God-given atmosphere that swaddles this earth and contending with the manmade stink that is spoiling it. His cerebration in behalf of human welfare ranges from the practical to the highly speculative. At one extreme, AeroVironment, the company he now heads, makes drag-reduction devices that save large trucks about 2¬¨¬®¬¨¢ a mile. At the other extreme, MacCready has served on a national panel investigating flying objects from outer space. The fact that, even in this day of climbing fuel prices, only about a fourth of the trucks in the U.S. use drag-reduction devices forces MacCready to believe that the bosses of the industry aren't particularly patriotic or smart. As a result of being a member of the panel investigating unidentified flying objects, MacCready concludes that "there will always be UFOs as long as there are people who believe in UFOs." Between these extremes, his company, AeroVironment, has been involved in projects making the most of geophysical functions—notably windmills and turbines to derive power from the air and the principal currents of the sea. The company also studies air pollution, using equipment that can trace noxious vapors and instruments that can determine the particular contaminants that are making people gasp and turn blue.

Getting something for nothing is a dream that dies hard. Alchemists of yore tried making gold out of base metals and never did. Today there are still well-educated noodlers who believe in perpetual motion. After graduating from Yale in 1947 with a degree in physics and a Phi Beta Kappa key, MacCready took a masters in physics and a doctorate in aeronautics at Cal Tech. Although he's too well disciplined academically ever to believe in something for nothing, when it comes to making a great deal out of almost nothing, he's a master.

Twenty years ago a retiring but ever curious English industrialist named Henry Kremer offered a £5,000 prize for the first successful man-powered flight. At Kitty Hawk back in 1903, to win its niche in history, the gas-powered Flyer I with Orville Wright at the controls spent a mere 12 seconds in the air and traveled only 120 feet The criteria laid down for the Kremer prize were much stiffer. To win, the pilot would have to lift off under his own power and complete a figure eight around two pylons half a mile apart. He could cover the course at any altitude, provided he cleared a 10-foot barrier at the start and at the finish.

The original prize was open only to subjects of the United Kingdom, but because by 1967 it was still unclaimed, Kremer doubled the purse and offered it to the whole world. Since the principal bugaboo seemed to be getting machines to execute a 180-degree turn, at the same time he offered £5,000 to the first three pilots of the U.K. who could fly a simpler course, simply weaving, slalom-style, around three pylons on a half-mile straight. In 1973 Kremer upped the figure-eight award to £50,000 and doubled the money for the simpler slalom test. As if in desperation to get somebody to win something, three years later he offered £1,000 to the first Commonwealth pilot who could even keep his machine in the air for three minutes.

Between 1960 and 1977 more than two dozen planes were designed to win Kremer money. Some never got off the drawing board: others never got off the ground. Canadians designed one super-sized eight-man machine and another for two men. Neither was completed, because of flagging interest and lack of funds. One dainty English beauty called Mayfly had a life even shorter than its name foretold. Before Mayfly was hauled out for its first test flight, the hangar roof collapsed, demolishing it.

Most of the Kremer-inspired craft did fly. Thirteen of them traveled farther than Flyer I did on its epic first hop at Kitty Hawk, but because the Kremer competition had become the recognized standard, all were deemed failures. Low-powered aircraft are necessarily light and large-winged, and consequently hard to turn. The best of the Kremer planes, Stork B, built at Nihon University in Japan, flew for nearly five minutes, but could never turn tightly enough to complete the figure eight.

Some experts concluded that because of its tough requirements, the Kremer competition was serving more as a deterrent than a stimulus to man-powered flight. Dr. Keith Sherwin, an aerodynamicist of the University of Liverpool, summed up the years of failure by saying, "At the present state of the art, it is rather like the Wright brothers attempting to fly the Atlantic in 1903."

Then along came MacCready. He first started thinking seriously about man-powered flight in midsummer of 1976. One year and a month later, in the early morning of Aug. 23, 1977, to be exact, at Shafter Field near Bakersfield, Calif., 24-year-old Bryan Allen, a trained biologist and devotee of hang gliding, backpacking and cycling, climbed into the MacCready-designed Gossamer Condor and pedaled up, up and away, over the 10-foot starting barrier, around the pylons and across the finish, clearing the final hurdle by two feet. All told, from liftoff to touchdown, Allen was in the air almost 7½ minutes and traveled nearly a mile and a half. Shortly after the Gossamer Condor won the ¬¨¬®¬¨¬£50,000 (at that time, about $95,000), Kremer, a man with a seemingly limitless store of enthusiasm and funds, announced two new competitions. One was a relatively trifling ¬¨¬®¬¨¬£10,000 to any plane not designed, built or flown by an American that could do what the Yankee-made Condor had already done. The second was a whopper: ¬¨¬®¬¨¬£100,000 for the first man-powered flight across the English Channel. No other machine has yet duplicated the flight of the Condor to win the lesser prize, but the Channel award didn't stay unclaimed for long. On June 12, 1979 it was won by another MacCready machine, Gossamer Albatross, with Allen again serving as pilot and power plant.

The Gossamer Condor now hangs in the Smithsonian Institution—a poor sort of museum piece in one respect. Because of its 96-foot wing span, it takes more space than Flyer I and the Apollo II command module combined. MacCready has received a number of aeronautical and engineering awards and a couple of honorary degrees for his achievements. The label "father of man-powered flight," now often hung on him, is certainly deserved, albeit historically insufficient. MacCready not only fathered man-powered flight but also fathered the boy-power that first lifted his machines off the ground. His two eldest sons, Parker, now 21, and Tyler, 18—both proficient at hang-gliding—served as pilots in early test flights. His youngest son, Marshall, an accomplished skateboarder and unicycle rider, pedaled the Condor and Albatross a couple of times for kicks. This past summer 13-year-old Marshall became the first human to fly under solar power, aboard the Gossamer Penguin, an experimental forerunner of the present high-flying Challenger.

During his own boyhood in New Haven, Conn. MacCready built model planes—gliders, monoplanes, biplanes, ornithopters, helicopters and autogiros. In 1941 he was national junior model-plane champion. Within a year he was flying himself. Five years later he took up soaring, winning three U.S. titles and one world title. Considering his practical experience and academic training, he seems the perfect sort to foster improbable flying machines, but the greater reason for his success exceeds such a simple explanation and in a sense contradicts it. Too much learning can be a burden.

MacCready succeeded where so many well-prepared men failed largely because he didn't let what he knew get in his way. Ray Morgan, manager of the Solar Challenger project, says, "Paul doesn't drown himself in the complexities of a problem. He can reduce things that would fill textbooks down to a bare equation with a few factors. He may not be exactly right, but he'll be close enough to determine what direction to take. That was the secret success of the Albatross, and that will be the success of this solar plane."

The Gossamer Condor weighed only 70 pounds; the Channel-crossing Albatross, only 77 (counting five pounds of water for Allen and two pounds of dew on the wing and stabilizer). The wing loading of the Condor wasn't only far less than that of rival machines built to win the first big Kremer prize; it was even less than that of efficient soaring birds, such as frigate birds, vultures and condors, which have selectively evolved through time. The weight disparity wasn't the only critical difference, but it is one that illustrates MacCready's practical approach. In the hangar where the fragile parts of the Condor were repaired again and again, a structural slogan evolved: "If it breaks, make it stronger. If it doesn't break, make it lighter."

Because his machines don't get much notice except when they do something spectacular, MacCready's successes seem to have happened overnight, but many man-hours went into their development. There were many trials and errors. According to those who have worked for and with him, success was in large part a result of MacCready's unflappable manner and his optimism, provided the latter is taken in small doses. "When you first meet him," Bryan Allen says, "he seems to be withdrawn. He doesn't act like an optimist, but actually, if he has any shortcoming, it's that he's sometimes a wild optimist. He cannot believe that he's going to fail. When everyone is preaching doom, he still believes. Sometimes it was almost aggravating."

Back on one day when a vortex of air from a powered plane more than 100 yards away broke the featherweight wing of the Condor, MacCready was asked if he thought his plane could win the Kremer prize. "It isn't a matter of 'if,' " he replied. "It's a matter of 'when.' " He admits his hopes weren't high on the day the Albatross took off across the Channel. In retrospect, he concludes that the attempt would have failed if someone up there had not been working overtime on his behalf. The someone he had in mind was Allen, who at times was pedaling desperately to stay even one foot above the water. It was reckoned that Allen could put out enough horsepower to keep flying for two hours. Traveling at about 12 mph, that meant he could make the 22 miles across the Channel on a calm day with energy to spare. Unfortunately, halfway across, the winds didn't stand fair for France, but quartered from ahead at six knots, forcing Allen to pedal for two hours, 49 minutes and travel about 35 miles through the air to reach Cap Gris-Nez. After exuberant helpers on the beach had broken one wing of his plane and a dog had bitten a piece out of it. Allen recalls MacCready telling him, "Take the rest of the day off, kid."

Project Manager Morgan remembers: "We were at Shafter testing the Penguin with Marshall MacCready flying it. At the start of a turn, it tip-stalled and spun down. It scared us all. First the plane stood on one wing, then the wing broke in three places, then Marshall fell out through the side of the plane from about eight feet up, and then the whole plane collapsed on top of him. We heard a scream, but Marshall wasn't badly hurt. Paul wasn't out there, and I had to phone him that Marshall was all right and the plane was a wreck. When I finished, Paul paused a moment and said, 'Ahah' and started talking about something he had on his mind."

MacCready was attracted to man-powered flight by the Kremer money. He went into solar-powered flight with a loftier purpose. Although he has lived most of his life in Southern California, an extravagant land, he's still a Yankee. To his way of thinking, the price of gas is not what it says on the pump, but more like $10 a gallon when the military cost of protecting our foreign supplies is tacked on. He's flying the Challenger primarily to promote solar cells as an alternative energy source. Although they demand a fancy price now, he feels they'll be cheap enough as soon as there is a reasonable market for them.

After she had flown those 22 minutes in the Challenger, only to be forced down by faulty control of the propeller pitch, Janice Brown was asked how she felt. She replied, "I had this feeling: Paul MacCready, you've done it again." During a short week in the air the Challenger performed well—remaining aloft as long as one hour and 55 minutes and working nicely even on overcast days—considering that the low winter sun had little oomph and the plane suffered mechanical ills that all newfangled machines are heir to. Even before the Challenger lifted off for the first time in Arizona, MacCready the optimist was laying greater plans. Once the sun starts climbing in the spring, perhaps the Challenger will make a flight between two major U.S. cities; if not that, then in summer, perhaps a flight from Paris to London (never from London to Paris, because the solar cells on the sloping wing can convert more energy when the plane is flying westward with the rising sun behind it). Never one to be trammeled by setbacks of the present, MacCready is even considering a three-leg journey, in which the Challenger would start under the high sun of North Africa, cross the Mediterranean, travel north over France and on to London.

When all that is done, it will be a pity that Jules Verne is no longer around to report it. It's his kind of fiction that MacCready is making come true.





MacCready inspects "Solar Challenger's" tiny electric motor, the tin-can-like object behind the prop.



The 98-pound Brown fills the fragile cockpit.



High above the Arizona desert, the plane's dark solar panels gather in energy from the sun's rays.