The National Aeronautics and Space Administration, which has a mandate to enhance the safety of air travel, has been suppressing huge quantities of data that apparently show the risks for civilian aircraft are much higher than commonly estimated.

The agency's lame excuses for refusing to release the information must make any traveler wonder how bad the implications might be.

Several years ago, NASA began interviewing airline and general aviation pilots about how often they saw risky incidents, like near collisions, or stressful last-second changes in landing instructions. Some 24,000 interviews were conducted over a four-year period before the program, and plans to interview air traffic controllers, flight attendants and mechanics, were scrapped.

When The Associated Press sought the data under the Freedom of Information Act, the request was rejected by a high NASA official. He said releasing the data "could materially affect the public confidence in, and the commercial welfare of, the air carriers and general aviation companies whose pilots participated in the survey." NASA's mandate is not to protect the commercial welfare of the airline industry, it is to enhance the safety of all who fly. It also apparently never occurred to NASA that suppressing this data could damage public confidence even more than releasing it.

One person familiar with the results told The AP that pilots reported at least twice as many bird strikes, midair near-collisions and runway incursions as other government monitoring systems show. Another person involved in the survey told us that the rates were higher than government regulators had been recording.

NASA now says the study was designed to develop a survey methodology, not to assess air carrier safety. It plans to complete a report on the methodology by year's end. That is not enough. In responding to the furor, NASA's administrator, Michael Griffin said, "NASA should focus on how we can provide information to the public - not on how we can withhold it."

We agree. Griffin should ensure that his agency analyzes its survey and then releases that analysis and all the interview data so that other experts can analyze it as well.