The report takes the F.A.A. to task for failing to pursue domestic security measures that could conceivably have altered the events of Sept. 11, 2001, like toughening airport screening procedures for weapons or expanding the use of on-flight air marshals. The report, completed last August, said officials appeared more concerned with reducing airline congestion, lessening delays, and easing airlines' financial woes than deterring a terrorist attack.
The Bush administration has blocked the public release of the full, classified version of the report for more than five months, officials said, much to the frustration of former commission members who say it provides a critical understanding of the failures of the civil aviation system. The administration provided both the classified report and a declassified, 120-page version to the National Archives two weeks ago and, even with heavy redactions in some areas, the declassified version provides the firmest evidence to date about the warnings that aviation officials received concerning the threat of an attack on airliners and the failure to take steps to deter it.
Among other things, the report says that leaders of the F.A.A. received 52 intelligence reports from their security branch that mentioned Mr. bin Laden or Al Qaeda from April to Sept. 10, 2001. That represented half of all the intelligence summaries in that time.