The telephone call, even though he expects it, always seems to come as a surprise and always brings a sense of foreboding.

"The call" means that John K. Lauber will grab a bag and head out with a crew of detectives to sift through the pieces of some blackened aluminum tube that, a few hours earlier, was an airplane.

"I know it's going to be a tragic scene," he said. "I know there are going to be lots of reminders of the tragedy. You know you're going to be faced with it."

Lauber, as a member of the National Transportation Safety Board, faces the kind of detective work for which he is never fully prepared. The scene is usually indescribably gruesome. For the next three or four or five days, from sunup to sunset, the NTSB's "Go Team" of investigators picks away at the hulk of the plane, searching for clues, sustained by adrenalin and a clinical detachment.

Lauber heads the investigation and feeds the insatiable appetite of the news media at briefings at the end of each day.

Somewhere in the middle of the action, when exhaustion begins to set in, the clinical detachment fails and Lauber seeks to get away and be alone.

"We are in a unique position to go in and find out what happened and, hopefully, learn something," Lauber said. "It's that sense of responsibility and purpose that allows all of us to get on with it, without dwelling on the obvious human tragedy. And yet, you can never get away from it. It's always there."

He said the Aug. 16 crash of Northwest Flight 255 in Detroit, which killed 156, was the worst crash investigation he has headed since his appointment to the NTSB in 1985.

"In terms of the carnage and destruction, it was a pretty horrible scene," he said. "As we got further and further into the investigation, and we started ruling out things like power-plant problems, it became obvious that we might be dealing with some significant human errors."

Before his appointment to the NTSB, Lauber, 44, was a research psychologist at the National Aeronautics and Space Administration's Ames Research Center in California. He had spent his career studying why people sometimes cause airplanes to crash.

The field is now known as "human factors" and its basic objective is to incorporate human-mistake tendencies into cockpit design in hopes of making airplanes more or less "blunder-proof."

"The kinds of things I have been doing my entire career have been dedicated to wiping out those kinds of accidents," Lauber said. "Suddenly, to find we have another one that involves this evokes a sense of frustration and resolve to make sure we don't have these kinds of things happen again."

Lauber said his type of research was resisted in its infancy by "hard" engineers -- those who designed and built engines and wings and other aircraft parts that behaved in controllable, predictable ways.

"One of the biggest battles at NASA was to convince the engineers that there was something to this 'human factors' stuff. It doesn't lend itself to families of curves," Lauber said.

But airlines, and eventually NASA, began to recognize that human error was causing most accidents, and that the notion that pilots all had "the right stuff" wasn't necessarily true.

"Wings weren't falling off. Engines were reliable," Lauber said.

The Boeing Co. has kept statistics on commercial jetliner crashes worldwide for nearly 30 years, finding 65.4 percent of all accidents attributable to the flight crew.

"When you count all human error -- air traffic controllers, dispatchers, weathermen and maintenance men, the number goes up to 80 percent," Lauber said.

The figures have remained about the same since Boeing started collecting them in 1959. Yet Lauber is the first specialist in "human factors" to sit on the safety board. In part, that may be because "human factors" research is less than 15 years old.

"We can't make humans mistake-proof," Lauber said. "We can do a lot to minimize {the problem} through equipment design."

Lauber, who holds a commercial pilot's license and a helicopter license, said he never expected he would carry his research to the NTSB and propel it into the national dialogue during this summer's aviation-safety debate. Lauber was so politically inexperienced that when he was appointed to the board as a Democratic member, the Senate Commerce, Science and Transportation Committee had difficulty tracing his ties to the Democratic Party.

On the board, Lauber is known for his outgoing, friendly manner. Yet he retains the demeanor of a cautious engineer. Last spring, for example, he was uncomfortable with NTSB Chairman Jim Burnett's urgent warning that airline safety was eroding -- pushing up to the "red line," as Burnett said.

Lauber said that now he thinks Burnett was "generally headed in the right direction," but the board's recommendations were more cautiously stated than the chairman's early warning had been.

"My concern was that there was a tendency to, if not overstate the case, then to not put it in context," Lauber said. "I was concerned we were creating a public crisis in confidence. While there was reason for concern, there was not cause for alarm."

He was angry with early leaks to reporters after the Detroit crash, and while he publicly praised new Federal Aviation Administration chief T. Allan McArtor for drawing attention to human error by telling pilots to "stay vigilant," Lauber privately fretted that McArtor was saying too much.

Lauber grew up in Ohio, the eldest son of the eldest son of a Mennonite farmer who homesteaded the farm. The family plan was for him to lead the next generation of Laubers at the farm on Lauber Hill.

But he had other dreams. He became a ham radio operator. He experimented in the basement with fuel for homemade rockets. He had a love of airplanes.

"I used to watch airplanes while I was sitting on the tractor," Lauber said. "I knew they were going faster than I was, so there had to be something to it."

He said he never felt a particularly strong pull toward the family religion, which shunned college and public service. He recalled only one incident when his family's view of religion collided with his world -- when man ventured into space.

"My grandfather admonished me severely after Sputnik," Lauber remembered. "He said we'd never get to the moon because God never intended us to."

In 1960, Lauber left the farm with big plans to become an engineer. But an experimental psychology course in 1963 changed his plans, and he changed majors and schools. He also took flying lessons, in an Aeronaca Champ for $13 a lesson.

By 1969, he had a PhD in psychology from Ohio State University and joined the staff of the Human Factors Laboratory at the U.S. Naval Training Devices Center in Orlando, Fla.

Four years later, he made the move to California and joined Ames. Two years after that, in 1975, at an aviation conference in Istanbul, human error was recognized "as the last frontier in aviation safety," Lauber said.

Two accidents helped turn airline thinking around, Lauber said. In 1974, a Trans World Airlines plane crashed into a mountain before reaching Dulles International Airport after the pilot apparently misinterpreted instructions from air traffic controllers. The other accident was a crash of a United Air Lines plane at Salt Lake City, in which the pilot landed short and hard.

Ames began collecting data, anonymously, from pilots who made mistakes. Airlines began developing "cockpit resource management programs" to teach crews to work together to solve problems during flight.

Now, human-factors research has spawned a new question with a new code name -- "cockpit complacency." Has too much automation been designed into machines so the pilots make a new and different kind of mistake? In the effort to design-out human mistakes by designing-in automation, has the industry crossed some self-defeating line?

"I don't think the line is defined," Lauber said. "That's one of the research issues we are just now beginning to come to grips with."