NTSB Press Release

National Transportation Safety Board
Office of Public Affairs


April 29, 2010

NOTE: Text was corrected May 4, 2010.

Washington, DC - National Transportation Safety Board Chairman Deborah A.P. Hersman said today that the use of data to manage and improve safety in the aviation industry has had a positive effect on the world's improving aviation safety record but she cautioned against over-reliance on these systems to the neglect of forensic investigation.

Addressing a conference of the International Society of Air Safety Investigators in Chantilly, Virginia, Hersman noted that "we have reached an era when aviation accidents are extremely rare..." One reason is the use of data - particularly, but not exclusively, Safety Management Systems (SMS) - in accident prevention and investigation.

The Board has been advocating the use of SMS for a decade, having issued 17 recommendations in favor of implementing SMS, five of them specifically directed at the aviation industry. When implemented correctly, Hersman said, "SMS holds real promise in a variety of scenarios." She noted several instances where SMS helped eliminate potential unsafe conditions, notably a corporate flight operation that used flight data to determine that high bank angles occurred on repositioning flights, and a review of commercial aircraft approach data that indicated a high rate of TCAS (Traffic Alert and Collision Avoidance System) warnings at a particular airport. In these instances, she said, "data management adeptly identified a clearly measurable set of information and allowed for a relatively simple and effective solution."

However, Hersman noted, SMS works well for companies that are already "getting it right," but may provide little more than false confidence for companies with less than robust safety cultures.

Also, there are accidents caused by a combination of factors that SMS cannot possibly detect. As an example, Hersman mentioned the British Airways Boeing 777 crash at Heathrow Airport two years ago involving a dual engine failure on approach. It was not data analysis that solved the mystery, but detailed forensic analysis; the circumstances were so unusual that a data analysis system would not pick them up.

Hersman said she hoped that with all the focus SMS will place on data collection and analysis, "let's not lose focus on outcomes. The success of SMS won't be measured by how much data we collect, but by how many lives we save."

"I will enthusiastically support any approach that will make our nation safer," she said. "But I think we need a measured approach - one that acknowledges the potential benefits and limitations of SMS, and further, doesn't discount tried and true methods for identifying vulnerabilities, such as accident investigations."

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NTSB Office of Public Affairs: (202) 314-6100



The National Transportation Safety Board (NTSB) is an independent federal agency charged with determining the probable cause
of transportation accidents, promoting transportation safety, and assisting victims of transportation accidents and their families.