Now that the film United 93 has rekindled the horror and the anger of September 11th, there are some questions to lay to rest. Again.
Why were there so few fighters standing by?
By the 1980s, air defense of North America was the sole responsibility of the Air National Guard which kept aircraft manned and ready for the sudden scramble to intercept an unknown that could by a Soviet Bear on a bombing mission.
The 1990s saw massive changes in the structure of the United States Air Force. Tactical Air Command, Air Defense Command, and Strategic Air Command all merged into a new command: Air Combat Command.
The B-52s and, FB-111s, and the new B-1Bs were pulled off full time ground alert since the Soviet Union had collapsed, so that threat vanished.
The same fate befell all the F-15 and F-16 Air National Guard wings dedicated to air defense. The planes were pulled off 5 minute alert status which meant two planes sitting fully armed and fueled with pilots aboard. Why? Because the Soviet Union was no longer a threat and money got tight after the 'Peace Dividend.' The strength of each ANG squadron also declined, from 24 planes per squadron during the Reagan buildup to 18 planes and then it leveled off at 15 planes per squadron. What also dwindled was the number of aircraft dedicated to defending US airspace. Instead of planes sitting ready on the ramp at places like Otis ANGB MA and Atlantic City, NJ, only the 102d FW at Otis ANGB had two F-15s sitting on the ramp ready but with no pilots in the cockpits. 1st FW, Langley AFB of the active duty USAF had two F-15s ready also, but again no pilots in the cockpits.
So that is why there were so few military fighters aloft on September 11th.
Now why weren't these planes deployed to protect Washington DC and New York City in an active manner?
NORAD, NEADS, SEADS, NWADS, SWADS, and ACC - which supplies the fighters have Rules of Engagement on dealing with Soviet bombers attacking or lost airliners, but nothing exactly for hijacked planes. Which is why we saw in United 93 the battle staff commander at NEADS pleading for some kind of RoE. As those 4,200 airliners were criss-crossing the United States, all the FAA and NEADS knew was that one or more of them had been hijacked. In fact the FAA had many more suspect jetliners than were actually hijacked. So what was NEADS supposed to tell those two F-15s from the 102d FW or the ones from the 1st FW? If a jetliner fails to respond to you in any of the standard ways, shoot it down? Was NEADS supposed to tell those pilots that? If NEADS had, the United States could have seen a few more airliners being shot down as civilian pilots did not react fast enough or the fighter pilots screwing up and shooing a jetliner down by accident. It would be KAL 007 all over again or USS Vincennes accidentally shooting down that Iranian airliner.
So F-15s ended up patrolling over New York City and Washington DC without proper orders due to the fog of war as United 93 crashed into a field and American 77 plowed into the Pentagon.