A kamikaze pilot. That is what the US launched to bring down the fourth airliner thought to be heading to Washington D.C. The pilot, one of two, had no live ammunition or any other weapons but the plane itself. If she caught up with the plane her only option was to crash into it -which is what she was prepared to do. [F-16 pilot was ready to give her life on Sept. 11.]
This from a New York Times post: "[t]he newly published multimedia document spells out precisely how the recordings contradicted the accounts of the senior officials." E.g., ". . . senior government officials, who in the weeks after Sept. 11, and for more than a year afterward, assured the public that fighter pilots had been in hot pursuit of the suicidal hijackers."
"The [9/11] commission discovered that little of that was true: of the four flights, military commanders had nine minutes’ notice on one before it flew into the World Trade Center, and did not learn the other three had been hijacked until after they had crashed."
It is this apparent need by the federal government to offer the "truth" as it see it that makes the 9/11 skeptics somewhat credible. It also deprives its citizenry of the actual and extremely heroic actions like that of the pilot ready to use her plane as the weapon. .