WASHINGTON — To help figure out what downed an Air Force radar plane in Alaska in September at the cost of 24 lives, investigators shipped some of the debris to Roxie C. Laybourne in Washington. She examined the clues. The clues were feathers.

Ms. Laybourne has spent 36 years at the Smithsonian Institution’s Museum of Natural History solving mysteries involving birds. She was able to confirm in an hour or so what investigators suspected: that a flock of Canada geese had flown into the engines of the Air Force E-3 AWACS. It’s a problem that costs the military and commercial airlines at least $150 million a year and puts lives at risk.

A 4-pound bird hitting a plane traveling at 300 mph — the typical speed of a commercial airliner after takeoff — hits with a force of 14 tons.

Some still-unidentified birds crossed paths last week with a United Airlines Boeing 747 over Sydney, Australia, causing one of its four engines to explode, apparently because the birds were sucked through a turbine and sheared off a blade.

There are about 8,000 collisions a year, 30 percent of them involving gulls, the Federal Aviation Administration says. Another 13 percent are caused by waterfowl, 12 percent by pigeons and doves, 12 percent by blackbirds and starlings and 10 percent by birds of prey, such as owls and hawks.

In Ms. Laybourne’s office, two owls glare down from a painting on the wall. Surrounding the work tables are cabinets filled with 650,000 stuffed birds, the third-largest collection in the world after the British Museum of Natural History in London and the American Museum of Natural History in New York. She examines each year about 400 feather samples sent from around the world.

There is much to ponder,since there are about 9,000 species of birds. With many of them, the feathers change colors seasonally. An average sparrow has 2,500 feathers; an average swan, 25,000. And each feather has a different shape and size.

That’s what Ms. Laybourne likes: the anatomical detail. The U.S. Fish and Wildlife Service sends her feathers taken from suspected poachers and asks her to name the bird.

“It’s a little like detective work,” she says. “You search and you search until you find the answer. What I like about it is, you learn something new every day.”

People who work in the field say that if anyone can make sense of such variety, it is Ms. Laybourne.

“I’ve seen what she does, and I understand some of the intricacies involved, and, believe me, she is amazing,” says Special Agent Douglas Deedrick, chief of the FBI’s hair and fiber identification unit and who studied informally under Ms. Laybourne for several years.

“She is the world expert on birds; that’s what people look to her for,” says Ed C. Cleary, the FAA’s wildlife biologist.

Ms. Laybourne’s findings are used by jet engine manufacturers to design bird-resistant parts and by airport managers who must shoo flocks from runways.

The technology of prevention ranges from mowing grass to firing cannons to broadcasting bird distress calls that ought to send flocks elsewhere.

Those measures sometimes fail. At New York’s John F. Kennedy International Airport, officials have resorted to shooting the sea gulls. After six years, the toll is about 45,000 birds.

“The problem is that all airports are vast open spaces,” says the FAA’s Mr. Cleary, “and birds are attracted to those open spaces.”

Ms. Laybourne started investigating bird incidents in 1960, when an Eastern Airlines Lockheed Electra struck a flock of starlings over Logan International Airport and crashed into Boston harbor, killing 62 people. It was the deadliest bird-related airline accident in U.S. history.

“They asked for our help, and John Aldrich, who was my supervisor, said to me, ‘Why don’t you take over the feather identification,’ which was something that was just coming into its own, and it interested me. So here I am,” she says.

On a recent afternoon, Ms. Laybourne, in a white lab coat, peered through her glasses at some dark, matted down plucked from the engine of a commercial airliner after it landed safely in Long Beach, Calif., on Dec. 1.

She washed the feathers in a very unscientific solution of water and soap flakes.

“Believe it or not, it’s the best thing for the job,” she says, mixing soap and water in a storage room filled with birds preserved in alcohol-filled glass jars.

She took the feathers to the examining tables, where she tried to match them with the birds in the drawers. Stumped, she placed them under a microscope to compare the “barbules,” tiny shafts that are a part of the feather. Magnified, they look like bamboo shoots.

The image confirmed her first suspicions: a pigeon.

Such work helped the FBI nab a husband who murdered his wife 10 years ago in Alaska. Authorities suspected the man of killing her and dumping the body in the waters off Kodiak. The body was never recovered, but when the woman’s down coat washed ashore, Agent Deedrick contacted Ms. Laybourne.

Ms. Laybourne matched the coat feathers — from a Chinese duck — to those taken from the back of the husband’s van.

“It placed the victim in the van and corroborated a lot of witness testimony about him putting the body in the van, and I’m sure it helped get the conviction,” Agent Deedrick says.

Ms. Laybourne never planned on a career in forensics. But as a girl in Fayetteville, N.C., she liked birds: “I’d lay on my back and watch them and wish I could fly.”

She has no favorite species but may have a favorite feather — the long, majestic, autumn-tone plume of a wild turkey.

She is bird-watcher, but not a serious one, and not beyond the 26 acres where she lives outside Manassas, Va.

“If someone comes out to visit me, we go out and do a little bird-watching,” she says. “But when you’ve spent seven days a week in the lab, you don’t have time to do much bird-watching.”

She graduated in 1932 from Meredith College in Raleigh, N.C., with a degree in science and math and went to work for the North Carolina State Museum of Natural History. She learned taxidermy and collected birds, fish and other specimens. She came to work for the Smithsonian on D-Day, June 6, 1944.

Since then, the skies have only grown more crowded, increasing the likelihood of bird-plane incidents, Mr. Cleary says. That is why Ms. Laybourne’s work is so important.

“It gives us a better handle of what’s happening up there,” he says. “And in the future, there’s likely going to be a lot more happening up there.”

Pub Date: 4/02/96