Summary

This letter responds to Congress's May 10, 2007, request that we address questions submitted for the record related to the May 9, 2007, hearing entitled The Future of Air Traffic Control Modernization.

Our responses are based on our previous work, preliminary results of ongoing work, and our knowledge of the areas addressed by the questions. We prepared our responses during May 2007 in accordance with generally accepted government auditing standards. Because our responses are based on our previously issued products for which we sought and incorporated agency comments, as well as updates that we obtained through interviewing Federal Aviation Administration (FAA) officials and reviewing their documentation, we did not seek agency comments on our responses to these questions.