Pedal-Pushing Woman to Fly Plane in Test

On the same day that Voyager touched down here to complete its record-breaking round-the-world trip, a flat-bed truck pulled into this sprawling air base carrying another airplane that will soon attempt to set a much different type of endurance record: distance for human-powered flight.

The plane is made of the latest light-weight materials and incorporates the most sophisticated aeronautical design concepts. But its success will depend largely on human willpower and physical endurance.

Sometime this month, pilot Lois McCallin will climb into the so-called Michelob Light Eagle and attempt to fly it around a triangular, 30-mile course over the dry lake bed. If successful, the feat would eclipse the previous record of 22 miles set by Bryan Allen when he flew the Gossamer Albatross across the English Channel on June 12, 1979, in two hours and 49 minutes.

Just a Warm-Up

But this month’s flight by the Eagle, expected to take about two hours, will be just a warm-up.

The Massachusetts Institute of Technology team that designed the Eagle hopes to use data from this flight to build a still lighter, even more sophisticated craft, to be named Daedalus. Either McCallin or another pilot will then attempt to fly it 69 miles from the island of Crete in the Mediterranean to mainland Greece, skimming over the waves. That attempt may occur next fall, if the plane can be built in time.

In ancient Mycenean myth, the master craftsman Daedalus constructed wings of wax, feathers and thread so that he and his son Icarus could escape from imprisonment in King Minos’ Labyrinth on Crete. Icarus perished, however, when he flew too close to the sun, which melted the wax in his wings and caused him to plunge into the ocean.

John Langford, head of MIT’s Daedalus Human Powered Flight Team, hopes their attempt will be more successful.

“Our previous (theoretical) studies showed that we are right on the very edge of feasibility,” said Langford, who is a graduate student in aeronautical engineering. “With some test flights here at Edwards, we think we can push it over the edge.”

Team’s 3rd Plane

Eagle is the third human-powered plane the MIT group has constructed and flown.

Chrysalis, built in 1979, was a biplane in which 44 different pilots made more than 350 flights of 50 to 100 yards in distance. Like many other human-powered aircraft before it, Chrysalis was too inefficient aerodynamically to travel much farther.

In 1984, the team’s Monarch B won a world speed competition, averaging a little more than 21 m.p.h. over a 4,950-foot course.

After the competition, Langford recalled, the MIT group wondered what to do next. “Eventually, someone suggested that it might be possible to retrace the route of Daedalus with a very long-range flight beginning in Crete.”

The group concluded that the design of the next generation plane was relatively straightforward. The greatest potential stumbling block in the Crete-to-Greece flight was the human factor.

When Allen, an avid cyclist who now works as a financial officer for a small company in Van Nuys, neared the end of his cross-channel flight, he was completely exhausted--so much so that he briefly considered crashing the plane on the beach (and thereby qualifying for the record). But he managed to continue another 100 yards, reaching the appointed touchdown site. “If it had been an additional 300 feet,” he said at the time, “I wouldn’t have made it.”

New Plateau of Endurance

The Daedalus flight would be more than three times as long as Allen’s. Technological improvements could reduce the energy required for the flight somewhat, Langford said, but the pilot also would have to reach a new plateau of endurance.

Enter McCallin, a 29-year-old financial analyst for a Boston investment company who read about the project in the Boston Globe.

The 5-foot, 6-inch, 122-pound McCallin’s hobby is competing in triathlons, in which contestants swim 2.4 miles, cycle 112 miles, and finish by running a marathon (26.2 miles).

“The cycling portion of the triathlon means she has developed the proper muscles for the aircraft,” said team member Steven R. Bussolari, “and the rest means she has the endurance.”

Flying the Eagle will be roughly equivalent, Langford said, to pedaling a bicycle at a speed of 25 m.p.h. on level ground. In laboratory tests at Yale University last year that mimicked the conditions McCallin would encounter in flight, she produced enough energy to power the Eagle for four hours. At the end of the test, she said she thought she could have gone another 30 to 60 minutes.

Langford has subsequently added a second triathlete/pilot, Glen Tremml, and the team may have as many as five prospective pilots for the Daedalus flight. “No pilot can be at the peak of their conditioning every day,” Langford said, “so we will probably pick whoever is at the top of their form on the day when whether conditions are right.”

“I think the chances are reasonable (that they can make it from Crete to Greece) if they get good weather,” Allen said in a telephone interview. “Their technology gives them a big edge.”

Canard Design Rejected

Construction of the plane itself began on June 2, 1986, and the first flight occurred at Hanscomb Field in Concord, Mass., on Oct. 3. The design team rejected the canard configuration--with the tail in front of the main wing--popularized by designer Paul MacCready in the Gossamer Condor and the Gossamer Albatross.

It was in September, 1977, that Allen performed the first sustained human-powered flight by navigating the Gossamer Condor around a 1.15-mile figure-eight course in six minutes, 22.5 seconds.

The MIT team adopted the conventional aircraft configuration--with the wing in front and the tail in the rear--because “it’s simply more efficient,” Langford said.

MacCready, head of the Pasadena-based consulting and development firm AeroVironment Inc., agreed with the MIT team’s design choice. “If we wanted to do what they are doing, we would do it the same way.”

MacCready also thinks the Daedalus flight will be successful. “There’s no reason why it shouldn’t work,” he said in a telephone interview.

Wingspan of 102 Feet

The fragile Eagle’s wingspan is 102 feet, about the same as a DC-9’s, and it weighs 88 pounds.

(Later this month, the team will put new wing tips on the craft to extend the wings to 112 feet, but the weight will not increase.)

The key to Eagle’s featherlike weight is the use of a light-weight skeleton of carbon fibers embedded in an epoxy resin. The ribs and the leading edges of the wings are composed of a plastic foam similar to that used in packaging. The wings and the tail are covered with Mylar, a thin, transparent plastic film that is practically weightless.

The high-efficiency, front-mounted propeller is connected to the pedals by a drive shaft that passes through two gear boxes. “That mechanism took us longer to build than anything else on the plane,” Langford said, “but it gives us 1% or 2% more efficiency than the chain drives used by MacCready and others. We thought that might make a difference.”

Overall, the Eagle will have 50% more strength and will cruise 30% faster than the Gossamer Albatross, and it will require 15% less energy to fly.

The team will use more advanced, and much more expensive, graphite fibers for Daedalus to reach the goal weight of 68 pounds. Use of these fibers, which cost as much as $500 per pound, enabled the team to extend the wingspan of the Eagle without adding to the weight.

The cost of the $74,000 feasibility study for the Daedalus flight was borne by MIT and the Smithsonian Institution’s National Air and Space Museum. Anheuser-Busch Inc. of St. Louis has donated more than $130,000 to support construction and testing of the plane.

Langford estimated that the cost of construction and the flight of the Daedalus will be $198,000.

McCallin and others have flown the Eagle many times at Hanscomb Field. But the longest runway at Hanscomb is only 5,000 feet, Langford said, and that limited the length of their test flights because they only fly over flat surfaces.

They have come to Edwards between semesters at MIT to take advantage of the wide-open spaces necessary for their low-level flights and for the usually calm air of desert mornings.

They plan to spend the first two weeks this month testing the reassembled plane, determining the proper altitude at which to fly it (probably about 10 feet), and learning how to make turns, which have not yet been attempted.