…n the daily flow of intelligence information the president receives, the warning of what appeared to be the threat of a conventional hijacking was not as serious as it appears in retrospect.

Since all Al Qaeda has ever been interested in is killing as may people as possible, why would the Bush administration imagine the threat to be of a “conventional hijacking?”
Bush Was Warned bin Laden Wanted to Hijack Planes
The warning of the hijacking was given to the president at his ranch in Crawford, Tex., where he was on vacation.

Taken together, the news of the C.I.A. warning and the information developed separately by the F.B.I. explains Mr. Bush's anger after Sept. 11 that intelligence gathered on American soil and abroad was not being centrally analyzed and that the agencies were not working well together.

Several times he has told audiences that he is working on solving that problem, and these days he is briefed jointly by the F.B.I and the C.I.A., ensuring that each hears information from the other agency.

It was not clear this evening why the White House waited eight months after the terrorist attacks in New York and Washington to reveal what Mr. Bush had been told.

But Mr. Fleischer noted that in the daily flow of intelligence information the president receives, the warning of what appeared to be the threat of a conventional hijacking was not as serious as it appears in retrospect. "We were a peacetime society, and the F.B.I. had a different mission," he said.
http://www.nytimes.com/2002/05/16/politics/16INQU.html?todaysheadlines