FBI agent Kenneth Williams's July 10 memo to FBI HQ read in part,
"The purpose of this communication, is to advise the bureau and New York of the possibility of a coordinated effort by Osama bin Laden to send students to the United States to attend civil aviation universities and colleges ...
"Phoenix believes that the FBI should accumulate a listing of civil aviation universities/colleges around the country. FBI field offices with these types of schools in their area should establish appropriate liaison. FBIHQ should discuss this matter with other elements of the U.S. intelligence community and task the community for any information that supports Phoenix’s suspicions. FBIHQ should consider seeking the necessary authority to obtain visa information from the USDOS on individuals obtaining visas to attend these types of schools and notify the appropriate FBI field office when these individuals are scheduled to arrive in their area of responsibility."
In the public redacted version, most all names in this memo were blacked out:
http://www.azcentral.com/arizonarepublic/news/articles/0724fbimemo24.html - if any of the 19 hijacker's names were included in this memo, it means that the FBI HQ knew the identities of terrorists who two months later would hijack four airplanes within the United States - and had been warned of the possibility of specific individuals who were feared to be at some point in a plot to hijack airplanes.
FBI agents took Zaccharias Moussaoui into custody on August 15, 2001. Here is Colleen Rowley's May 21, 2002 memo to FBI Director Robert Mueller concerning Moussaui:
http://www.time.com/time/covers/1101020603/memo.html Rowley writes,
"As the Minneapolis agents' reasonable suspicions quickly ripened into probable cause, which, at the latest, occurred within days of Moussaoui's arrest when the French Intelligence Service confirmed his affiliations with radical fundamentalist Islamic groups and activities connected to Osama Bin Laden, they became desperate to search the computer lap top that had been taken from Moussaoui as well as conduct a more thorough search of his personal effects. The agents in particular believed that Moussaoui signaled he had something to hide in the way he refused to allow them to search his computer."
The August 6 PDB states,
"Nevertheless, FBI information since that time <1998> indicates patterns of suspicious activity in this country consistent with preparations for hijackings or other types of attacks, including recent surveillance of federal buildings in New York."
Here is the nutshell:
July 10, 2001: FBI agent in Phoenix warns of suspected terrorists taking flight training in the US with the intention of hijacking airplanes. It's
possible the memo mentions 9-11 hijackers or individuals involved in suspected plot<s> - by name.
August 6, 2001: President Bush receives a memo warning of a long history of a desire by terrorists to hijack US flights and commit other acts of terrorism within the United States. It concludes by summarizing that there are ongoing activities
"in this country consistent with preparations for hijackings or other types of attacks."August 15, 2001: Accused 9-11 conspirator Zaccharias Moussaoui in custody, FBI field agents request for a search warrant on Moussaoui is denied.
September 11, 2001: Four domestic flights hijacked by terrorists trained in US flight schools.
There was an intelligence failure which reaches from FBI field offices all the way up to the Oval Office - the President was made aware in a general fashion that a plot to hijack airplanes may be in the works. The FBI had specific information on Moussaoui - it's the JD's contention that Moussaoui was the 20th hijacker. The FBI could possibly have had the names of some of the (other?) 19 hijackers.
Anyway, I'm thinking that this August 6 memo means much more when looked at along side Kenneth Williams' memo and the arrest of Zaccharias Moussaoui.