The Federal Aviation Administration (search) focused on the danger of explosives aboard planes rather than a suicide hijacking before the Sept. 11 attacks even though its own security officers warned terrorists might try to crash an airliner, a federal panel said Tuesday.

The FAA's Office of Civil Aviation Security (search) considered the risk of a suicide hijacking at least as early as March 1998, says the preliminary report by The National Commission on Terrorist Attacks Upon the United States (search).

The commission report acknowledges there was no specific intelligence indicating suicide hijackings would occur but says the FAA still had a responsibility to protect the flying public against such a threat.

The commission wrapped up two days of hearings that focused on aviation and border security lapses. The panel, which has been investigating the Sept. 11 attacks for a year and has held seven public hearings, wants Congress to extend its May 27 deadline by at least two months, saying it needs more time to review all the material.

At Tuesday's hearing, the commission provided documents showing the FAA was aware of the possibility of suicide hijackings but did not pass the information along to airlines.

In a presentation to airline and airport officials in early 2001, the FAA discounted the threat of a suicide hijacking because there was "no indication that any group is currently thinking in that direction." And when the agency issued a terrorism warning to air carriers in July 2001, it noted the risk of explosives inside luggage but did not mention suicide hijackings.

At a commission hearing, panel member Timothy Roemer read from an FAA document published in the Federal Register on July 17, 2001, stating that terrorism could occur "anytime, anywhere" in the United States and cautioning that the risk "needs to be prevented and countered."

"The dots are connected and they're large," said Roemer, a former Democratic congressman from Indiana. "Why didn't they result in a change in policy?"

Cathal L. Flynn, former associate administrator of civil aviation security at the FAA, responded that the agency only had a generalized sense of the risk and that security efforts were hampered somewhat by poor communication with the FBI.

"It isn't that we disregarded them. There were disconnects," he said. "How would you coerce a pilot to fly into a building that's got people in it? ... How would you do that? The notion of a full-fledged Al Qaeda member being a pilot ... did not occur to me."

Executives from United Airlines and American Airlines told the commission they rely on the FAA and federal agencies to provide guidance on aviation security as well as counterterrorism efforts. They proposed a more integrated security plan to improve coordination among federal agencies.

Other preliminary findings disclosed Tuesday by the commission:

— Nine of the 19 Sept. 11 hijackers had been stopped by the airlines for additional security screening.

— Weaknesses in airport screening of carry-on baggage in the 20 years prior to 2001 were rampant and widely reported in popular literature, which the hijackers apparently read and used to their advantage.

The 10-member, bipartisan commission was established by Congress to study the nation's preparedness before Sept. 11 and its response to the attacks, and to make recommendations for guarding against similar disasters.

On Tuesday, the panel also formally asked Congress to extend its deadline for a final report by at least two months, or to July 26, citing a need for full analysis of reams of documents and interviews with government officials about the disaster.

"As much as we have learned about the enemy, there is much more we need to learn about them," said former Indiana Rep. Lee Hamilton, the panel's vice chairman.