Crash Lab Picks Up Pieces


Students Examine Aircraft Wreckage to Reconstruct Accidents


PRESCOTT, Ariz. -- The smashed and blackened remains of the aircraft are scattered over the ground just as they were when the planes went down.

The crashes happened elsewhere. The wreckage was trucked to this facility so that students -- future pilots, mostly, and those pursuing careers as accident investigators -- can reconstruct the last few minutes of each doomed flight.

Bill WaldockIf you ever fly in an airplane, what happens here could have a bearing on your chances of being in an accident. And on your chances of living through one.

Bill Waldock sifts through the debris. To the untrained eye, this is just a big junkyard. But if you know what you're looking for, he says, the burned and battered pieces tell a story -- "What? Why? How?"

Welcome to the Robertson Crash Laboratory at Embry-Riddle Aeronautical University. Its 8 1/2 acres hold what's left of more than a half-dozen downed aircraft.

There's also a technical library and database of aviation accident reports dating back to 1938. A materials laboratory with engines, instruments and cabin furnishings from Boeing 737 and DC-8 aircraft, plus components that experienced in-flight failure, all available for inspection and analysis.

Waldock, professor of aeronautical science and associate director of the university's Center for Aerospace Safety Education, teaches a range of courses from hands-on accident investigation to aircraft accident dynamics.

His message is always the same: There's no such thing as an aviation accident that had to happen.

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Waldock guides students Alberto Moran, Sean Ordonez and Katie Rudd through the outdoor crash lab. The most complex accident scenario they inspect is what remains of a twin-engine Cessna, splattered over a 110-foot-long re-creation of the actual impact area.

The plane experienced an in-flight explosion and fire eight minutes after taking off from Las Vegas, where it had been refueled, Waldock says. It remained airborne for five more minutes before going down and killing both people on board.

"Something happened to cause (the pilot) to depart from controlled flight," Waldock tells the students. "But what?"

The students poke through the wreckage as Waldock shows them how to look for clues and decipher the stories they tell. He picks up a small turbine assembly and points to the fan blades, only a few of which are bent.

"This is from the supercharger on the left engine," he says. "This spins at 8,000 to 10,000 rpm. It tells us that the engine was not running when it hit the ground."

Had the engine been powered, obviously the blades, turning at extremely high speed, would all show severe damage as they were brought to an abrupt halt by the crash.

"This really helps us put it all together," Rudd, 28, a senior, notes later. She has returned to Embry-Riddle after a six-month internship at the National Transportation Safety Board's field office in Denver, Colo.

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Embry-Riddle offers students a minor in aviation safety. Class work is heavy on the technical aspects, but there's also an emphasis on the "human factors," or, as Waldock puts it, "why people make mistakes."

Human error constitutes the "largest group of events" that leads to accidents, he adds.

"But 'pilot error' is a bad word. It's not just pilots who make mistakes, but everybody else's mistakes come to rest on the pilot. It's in his power to trigger, or stop, the accident."

Accidents themselves, says Waldock, "are never single-event occurrences. They're a chain of events, and what we try to do is identify that part of the chain where we can reduce the likelihood of something happening."

Even in cases of apparent structural failure or metal fatigue, Waldock says, a chain of events can often be traced back years to defects in the design, manufacture and subsequent inspection and maintenance procedures. "At some point in almost everything we can identify in a crash, human error is involved."

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"A pretty substantial piece of the airplane is not here. It's very important," Waldock advises the three students. They sift through the debris, pick up pieces, turn others over in their search for evidence.

Waldock finally clues them in: What's missing is one of the engines, which lies some distance away. A tangled propeller means the blades were spinning at impact. More clues: Popped rivets on the left wing, along with burn "feathering" on the left side and none on the right, and a cracked left aileron.

"He couldn't keep the wing up," Waldock notes.

It takes a knowledge of metallurgy, mechanics, flight dynamics, and airframe and engine design to piece a crash scenario together. In this case, it began with a small crack in a 20-year-old fuel tank in the left wing.

In the fatal sequence of events that followed, no more than an ounce or so of gasoline escaped into the tightly enclosed space that housed the fuel lines. But heat from the engine raised it to the flash point.

Waldock thinks careless refueling opened a crack in the tank. The resulting explosion severed the fuel lines to the engine, blew the wing open and damaged the aileron.

Could this disaster have been prevented?

"Yes, unequivocally!" he says. "One hundred percent of the time!"

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As airplane cockpits become increasingly computerized, a new risk factor -- "automation complacency"-- is emerging, Waldock says.

"We're seeing a change in human error related to automation. It pulls the pilot away from flying the airplane. With an overreliance on automation, the pilot's role becomes more of a monitor than an actual participant, and it takes a longer time to understand what's happening if something goes wrong."

But, he adds, "Of course the newer airplanes are more reliable."

The bottom line, though, is that "airplanes are only as safe as we make them."

The major U.S. air carriers had no fatalities last year, Waldock points out. But was it a safe year for aviation?

"One year of no fatalities means nothing, other than one year of no fatalities," he says.

There were a pair of major disasters -- TWA Flight 800 off Long Island, and ValuJet Flight 592 in the Florida Everglades -- three years earlier, in 1996. Everyone aboard both planes, 340 in all, died.

"The difference between the years was luck," Waldock says. To be meaningful, safety statistics have to be spread over a much longer period, say 10 years, not just one.

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Waldock opens a drawer containing file after file of the nearly 200 crashes he's investigated. There are pictures of smashed airplanes, and the torn and charred human remains inside.

As if the pictures aren't enough, the reality of what happens to the human body when it's subjected to a tremendous impact is brought home in the classroom and in the crash lab.

"In a crash environment we're dealing with a lot of torn, twisted metal," Waldock emphasizes to his morning class on aircraft crash management. Hence the lacerations, contusions, concussions, broken bones and other "blunt-force impact" injuries.

And then there's fire, fed by thousands of gallons of gasoline or jet fuel.

"Burns don't require actual contact with the flames," he says, and aircraft fires are among the hottest.

To the usual three degrees of burns, he adds a fourth -- "thermal amputation." Some of his pictures show charred torsos, the limbs missing.

Outside in the crash lab, students are reminded that blood-borne pathogens are always a danger at any accident site. One of the wrecks, a two-seat, single-engine aircraft that crashed in Oregon, has a cockpit doused with ketchup.

"If they get any red on them, they flunk," Waldock says.

Later, during an afternoon class on crash survival, Waldock screens a film taken inside aircraft fuselages during drop tests designed to simulate actual impacts. The bodies -- dummies in this cases -- are thrown about violently.

No matter how well-secured the pilots are, they always crash into the cockpit controls.

With the trend to "glass cockpits" where computer screens and flat buttons are replacing the traditional instruments, levers and switches, isn't the danger to flight crews lessened? one student asks.

"Would you want your face hitting a TV screen?" Waldock answers.

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Big crashes make for big headlines, but they don't give a true picture of what aviation safety is all about, says Waldock's colleague, John Johnson, an assistant professor of aeronautical science.

"The system is so good and accidents happen so infrequently that it's hard to get a good statistical model," Johnson says.

His concern is that the airlines have people -- he unabashedly refers to them as "bean counters"-- saying they must consider the cost of safety vs. the cost of the accident itself. That means the costs of replacing the aircraft, increased insurance premiums, even the payouts to the victims and their families.

"The public doesn't want to hear it, the airlines don't want to admit it, but they are selling tickets based on a perception of safety," Johnson says.

On May 11, 1996, that perception caught up with the 110 passengers and crew aboard ValuJet Flight 592. The DC-9, nearly 30 years old and with an intense blaze in its cargo hold, plunged into the Florida Everglades.

"The cargo compartment was designed around the idea that . . . it didn't need fire detection equipment because if there was a fire, it would burn all the oxygen before the flames reached the rest of the plane," Waldock says.

Ironically, the oxygen generators in the cargo hold not only caused the fire, but generated enough oxygen to keep it going longer than the plane's designers had envisioned.

As a result, all DC-9s now carry fire detectors in their cargo holds.

The accidents notwithstanding, boarding a commercial airliner is still several times safer than getting into an automobile, Johnson says.

"You can spend so much on safety you'll go out of business," he adds. "And the only way to make air travel absolutely safe 100 percent of the time is for the airplane to never leave the ground."

In the meantime, planes will continue to crash, and travelers will continue to buy tickets, Johnson says. In the final analysis, he adds, "it's the flying public that decides issues of safety vs. cost."

Says Waldock: "I've never seen an accident that couldn't have been prevented. But whether we choose to prevent one is another matter."

By James Steinberg

Reprinted from the June 1, 1999, issue of the San Diego Union-Tribune with permission

For a schedule of upcoming Aviation Safety Certificate Programs, contact Embry-Riddle's Center for Aerospace Safety and Education at (928) 777-6961 or access www.avsaf.org.