Computer scientists at NASA Ames Research Center's Computational Sciences Division have invented the Aviation Data Integration System (ADIS), a Web-based archive that integrates environmental data from more than 100 airports, giving flight safety analysts access to weather data previously unavailable to them.

"Without environmental information, safety analysts have a tough time sorting out important events," said Tom Chidester, director of NASA's Aviation Performance Measuring System (APMS), the NASA Ames project that advances analysis of flight data.

For example, a deviation from glide slope, an instrument-guided vertical path to the runway, in clear daylight could be insignificant or even purposeful. The crew might be avoiding wake turbulence from an aircraft that just landed. But the same deviation during low visibility, when the crew cannot see the runway or obstacles, might be of greater concern.

ADIS allows the linkage of a flight to information about its environment.

What's most impressive about ADIS, though, is what it doesn't provide.

Airlines that are trying to find safety problems earlier can obtain some safety data only because pilots voluntarily report it, or allow flight data to be monitored through confidentiality agreements negotiated among airlines, airline employee representatives and the Federal Aviation Administration (FAA).

When airline safety analysts examine data obtained through a promise of confidentiality, the airlines cannot examine or reveal information that will identify the pilot or other flight personnel who have reported or are involved in an event. Voluntary narratives from mechanics, pilots and flight attendants and the monitoring of flight data have proved essential to devising new methods for flight safety. Because environmental conditions change rapidly, weather data is associated with a certain time and date. Hence, providing weather data can in effect identify a flight number, its pilots and other personnel involved.

ADIS integrates the environmental data without disclosing identifying information, said ADIS project lead Deepak Kulkarni. "We defined a very secure schema that allows the airplanes to store the data in encrypted form in such a way that the data will be used only by the computer program, and will never be revealed to a user."

The project's engineers also solved the tough problem of physically integrating the environmental material. Each airport reports weather data types at varied intervals, some at each hour, others every few minutes or even seconds and in different abbreviations and formats.

ADIS matches them up, updating and archiving data such as wind speed, visibility and which runways are in use, so that aviation safety analysts can access, retrieve and review the information through a secured Internet link.

"The ADIS team solved both the data-integration and confidentiality-maintenance problems in one invention," Chidester said. "The reaction from airline users has been extremely positive."

Three airlines have used ADIS with positive results. One reported that their analysts are now routinely using ADIS to place in context flight data events and to verify weather conditions during maintenance-related events.

Another airline reports that it routinely uses ADIS to document reported weather conditions around the time of events disclosed through voluntary reports. Union representatives at these carriers also have praised the technology for its key function -- providing the context while maintaining the confidentiality of reports and flight data. The FAA Office of Voluntary Safety Programs is making the ADIS archive available to airlines.

"The ADIS system has been extremely well received by the airline industry and the FAA," said Capt. Bob Lynch, a project manager for APMS.

APMS develops advanced concepts and prototype software for aircraft flight data, and is funded by NASA's Aviation Safety and Security Program. The APMS team is made up of researchers from the Computational Sciences and the Human Factors Research and Technology divisions at NASA Ames Research Center, Battelle Memorial Institute and Pro Works Inc.

Organizations interested in licensing ADIS can contact Ames Research Center's Office of Technology Partnerships.