The Official Account
The attack on the Pentagon by American 77 (under the control of al-Qaeda) could not have been prevented for four reasons.
- First, although the FAA had received multiple signs before 9:00 AM that this plane was suffering an in-flight emergency,  the FAA did not notify the military about this flight until 9:24 — at which time it reported that the flight, which may have been hijacked, appeared to be heading back toward Washington. 
- Second, although Andrews Air Force Base was only a few miles away, it had no fighters on alert. 
- Third, the only fighters on alert in the Eastern United States were two at Otis Air Force Base, which were already occupied protecting New York City against further attacks, and two fighters 130 miles away at Langley Air Force Base. 
- Fourth, the Langley fighters, which did not get airborne until 9:30,  were still 105 miles away when the Pentagon was struck at 9:38. 
The Best Evidence
Discrepancies in both time-lines and aircraft availability challenge the given reasons for the claim that the attack at the Pentagon could not have been prevented:
- First, an FAA memorandum of May 22, 2003, to the 9/11 Commission said: “Within minutes after the first aircraft hit the World Trade Center at 8:46, the FAA immediately established … phone bridges [with the military]. … [T]he FAA made formal notification about American Flight 77 at 9:24 AM, but information about the flight was conveyed continuously during the phone bridges before the formal notification.”  This statement was read into the 9/11 Commission’s record.  Loss of communication with American 77 was reported by the FAA Indianapolis Center “[s]shortly after 9:00.” 
- Second, Colin Scoggins,  the military specialist at the FAA’s Boston Center, stated that although the District of Columbia Air National Guard (DCANG) did not “have an intercept mission” — it was not one of the country‘s seven military bases that are ready to intercept flights every hour of the year — it did “fly every morning” and that under the circumstances NEADS “could have grabbed … those aircraft.” 
- Third, Scoggins said that fighters at Atlantic City, Burlington, Selfridge, Syracuse, and Toledo would also have also been ready to go.  Shortly after the second tower was hit at 9:03, an ANG commander at Syracuse told NORAD: “Give me 10 minutes and I can give you hot guns.”  If this request had been made at 9:10, this statement indicates, these fighters could have been in the air in time to protect the Pentagon.
- Fourth, even if fighters had to be sent from Langley Air Force Base (as the official story claimed in bullets 3 and 4, above), they should have been airborne long before 9:30 (see the first bullet under the Official Account, above).
References for Pentagon Point 1
- “By 8:57 a.m., it was evident that Flight 77 was lost.” Matthew L. Wald and Kevin Sack, “’We Have Some Planes,’ Hijacker Told Controller,” New York Times, October 16, 2001
- “NORAD’s Response Times,” North American Aerospace Defense Command, September 18, 2001. “Officials: Government Failed to React to FAA Warning,” CNN, 17 September 2001.
- Pentagon sources said that Andrews “had no fighters assigned to it” (USA Today, September 17, 2001). Major General Larry Arnold – the commanding general of NORAD’s Continental Region – said: “We [didn’t] have any aircraft on alert at Andrews” (MSNBC, 9/23/2001).
- Michael Bronner, “9/11 Live: The NORAD Tapes,” Vanity Fair, August 2006: 262-285, at 268. (Bronner, who had been an associate producer of the film United 93 [which had faithfully portrayed the 9/11 Commission’s new account of this flight], was able to write this article because he was the first journalist to be given access to tapes provided by NORAD, which were used by the 9/11 Commission for its new account of American 77 [as well as the other accounts].)
After 9/11, Colonel Robert Marr, the head of NEADS, said: “I have determined … that with only four aircraft, we cannot defend the whole northeastern United States” (James Bamford, A Pretext for War [New York: Doubleday, 2004], 60-61).
The 9/11 Commission said that calling on other air bases would not have helped, because these “[o]ther facilities, not on ‘alert,’ would need time to arm the fighters and organize crews.” The 9/11 Commission Report, p. 17.
- “NORAD’s Response Times.”
- “NORAD’s Response Times,” September 18, 2001; also “Where System Failed: Air attack on Pentagon indicates weaknesses” (backup), Newsday, September 22, 2001.
- “FAA Communications with NORAD On September 11, 2001: FAA Clarification Memo to 9/11 Independent Commission,” May 22, 2003.
- “FAA Communications with NORAD on September 11th, 2001,” read into the record by Commissioner Richard Ben-Veniste, 9/11 Commission Hearing, May 23, 2003.
- The 9/11 Commission Report, 24.
- Scoggins was cited three times in The 9/11 Commission Report, p. 458, and in a Vanity Fair article by Michael Bronner, “9/11 Live: The NORAD Tapes,” August 2006.
- E-mail from Scoggins to David Ray Griffin, 20 December 2006.
- E-mail from Scoggins, December 20, 2006.
- William B. Scott, “Exercise Jump-Starts Response to Attacks,” Aviation Week and Space Technology, June 3, 2002. The more complete statement was: “At Syracuse, N.Y., an ANG commander told [Col. Robert] Marr [the battle commander of NEADS (the Northeast Air Defense Sector of NORAD)]: ‘Give me 10 min. and I can give you hot guns. Give me 30 min. and I’ll have heat-seeker [missiles]. Give me an hour and I can give you slammers [Amraams].’ Marr replied, ‘I want it all.’” The point is that, if Marr had not insisted on having “it all,” he could have had fighters with hot guns within 10 minutes.