Reading The Wreckage
Air crash investigators train students to fit little pieces into the big picture.
- By Eric Adams
- Air & Space magazine, July 2001
(Page 2 of 5)
“The nose gear is collapsed, and both prop blades are bent,” the student says.
“Good. And what does that tell you?” Wall asks.
“The prop was rotating at impact.”
An hour later, the class has it down: They can spot bowed flanges, shorn bolts, torsion, and ground scars immediately. Learning how to accumulate such details and objectively assess their significance, Wall tells them, is the first step toward narrowing the possibilities for the cause of the accident. The real answers, after all, are often very far from what first impressions may suggest and usually include multiple failures, so investigators must have a comprehensive understanding of what the aircraft—and, ultimately, its crew—has gone through. Wall describes some of the analytical tools available. He tells them to document the site with videos, photographs, and grid sketches showing debris distribution lines. Another trick is vector analysis, drawing arrows on the wreckage that show the direction that forces are being applied. “You’ll get the big picture very fast,” Wall says.
Emphasis on the big picture is clear in the range of the course curriculum. It’s a general introduction, and it’s just one of many that investigators will take throughout their careers. The class, which is taught by TSI, NTSB, and FAA staff as well as aviation industry experts, covers all types of aircraft and gives equal weight to both clinical discussions of aircraft component failure modes and the human side, describing how to work with witnesses, survivors, and family members and what investigators might experience at the site. “When you arrive at a bad accident site, I guarantee you you will not sleep that night,” warns Frank Del Gandio, an FAA investigator who lectures on crash-scene biohazards, including blood-borne pathogens such as the hepatitis virus and HIV. “In fact, you might find you’re not sleeping for days. That’s normal. Don’t worry. But you need to focus on that investigation. Focus on the people you might be able to help in the future.”
That’s a virtual mantra for accident investigators, who must often work at remote and inhospitable sites and with a mind-numbing collection of variables. Their cause, though, is safety—to figure out precisely what happened at each accident so that the problem can be prevented from happening again. According to the NTSB, there are roughly 2,000 aviation accidents per year, most involving small general aviation aircraft and about 700 involving fatalities. All are thoroughly investigated with a variety of team configurations that can include representatives from the airline, if applicable, the aircraft manufacturer, and any part suppliers or airport personnel who might contribute useful records or data. If there are fatalities, the NTSB will lead the on-site investigation. If not, the board might delegate the investigation to the local FAA office. (The FAA, which is responsible for regulating the aviation industry and operations, always participates in investigations in support of the NTSB.) In all cases, the facts are reported to the five-member board, which will review the accident, develop a probable cause, and possibly issue recommendations for the FAA to enact.
The Transportation Safety Institute, a Department of Transportation division charged with training investigators of aviation, highway, and marine accidents, trains some 600 FAA investigators a year. It also opens its doors to tuition-paying military and commercial airline safety specialists. In the course I’m participating in, most of my classmates are these specialists, who oversee flight operations with an eye toward safety procedures, training, and maintenance and who might eventually participate in investigations that their companies or military units conduct in support of or in addition to an NTSB inquiry.