The CIA's plan to derail al-Qaida has been in existence since 1999, Tenet said. It included developing intelligence sources inside Afghanistan. Between 1999 and 2001, the agency's human agent base against al-Qaida grew by over 50 percent. The agency used over 70 sources and subsources, 25 of whom operated inside Afghanistan. It moved its spy satellite over the country to increase coverage of bin Laden's terror training camps.

The staff report suggested the intelligence community was unprepared for a surprise attack like the one orchestrated by al-Qaida.

For example, there was no evident analysis within the intelligence community about the danger of using boats to bomb a tanker before the attack on the USS Cole in October 2000. The staff report noted that expertise about such a surprise attack existed within the community at the Office of Naval Intelligence.

And some of the threat reports pouring in warned about the use of aircraft before the Sept. 11 attacks, the report stated.

"The most prominent hijacking threat report came from a foreign government source in late 1998 and discussed a plan for hijacking a plane in order to gain hostages and bargain for the release of prisoners such as the "Blind Sheikh," it said.

Other threat reports, according to the staff report, mentioned the possibility of using an aircraft laden with explosives to attack a U.S. city. That report was circulated in September 1998, but neither the source's reliability nor the information could be corroborated.

Despite an Algerian group's attempt to fly an airliner into the Eiffel Tower and a terrorists linked to Ramzi Yousef plotting to fly a plane into CIA headquarters in Virginia, the staff report found that the Counter Terrorism Center did not analyze how a hijacked aircraft or other explosives-laden aircraft might be used as weapon.

"If it had done so, it could have identified that a critical obstacle would be to find a suicide terrorist able to fly large jet aircraft," the report stated. "This had never happened before 9/11."

As the commissioners heard testimony, an aide for the Rep. F. James Sensenbrenner (R-Wis.), chairman of the House Judiciary Committee, passed out a statement from him calling for Commissioner Jamie S. Gorelick to resign because of a memo she authored in 1995 when she was the deputy attorney general.

The memo, released on Tuesday by Attorney General John Ashcroft, urges law enforcement agents to keep a wall between intelligence operations and criminal investigations. Ashcroft said the memo showed that the wall was the policy of the Clinton administration and it undermined the department's ability to detect the impending al-Qaida attacks.

"Ms. Gorelick has an inherent conflict of interest as the author of this memo and as a government official at the center of the events in question," Sensenbrenner said.

Several commissioners rejected Sensenbrenner's call for Gorelick to step down.

"People ought to stay out of our business," said Kean, former Republican governor of New Jersey.

Commissioner Slade Gorton, a Republican senator from Washington for 18 years, said Gorelick's experience was an asset to the commission and that she had acted properly throughout her tenure on the 10-member panel.