They were scrambled, and the tapes of the conversations between the pilots and their controllers was made public about two weeks ago and published in just about every news media globally.
It was certainly in all the UK newspapers, both left and right wing ones.
The facts are that an organisation called NORAD is responsible for the air defence of the United States and Canada, and at the time of 9/11 the threat assesment of attack by the air was very low.
Therefore there were only four fighter aircraft on the Eastern Seaboard of the U.S ready and "gunned up" to scramble and meet a potential threat.
Standard operating procedures were designed to combat the Russians and so if those jets were scrambled they would head out east over the Atlantic to prepared intercept points, which is exactly what they did when they were finally sent up.
Quite simply 9/11 took everyone by surprise and there were key events that delayed the fighter action.
One of the first things the hijackers did was to turn off the aircraft transponders, which means that a civilian aircraft simply disapears off the air traffic control screens.
The skies over the USA are filled with thousands of aircraft every day and therefore without a transponder signal to identify it you literally have a needle in a haystack.
So the planes were sent up but vectoring them onto the hijacked aircraft was virtually impossible in the case of the two which hit New York.
When it became apparent what was happening they were vectored to Washington (incorrectly to the White House initially) but even at full power they had a lot of ground to make up. Don't forget that airliners at full power are not exactly slow. I have been on a 747 with a tailwind doing over 650 mph which is not bad for 300 tons of aircraft.
It is now pretty certain that they were not far behind flight 93 and did request authority to engage, ie shoot it down. That authority was initially denied and was not given until 17 minutes AFTER flight 93 crashed into the field.
There is no doubt in my mind that the jets were sent up, but that they were always running after the game and had unclear direction and a lot of confusion.
It is really easy for us to look back in hindsight and be smart after the event about what should have happened, but if you cast your mind back to the day itself everyone was completey shellshocked and wrongfooted.
Its a very different game now and with the recent arrests in London over the next few days there were a lot of fighter planes in the air over the UK.
A friend who is an airline pilot has told me that on flights to the U.S now, he is regularly "intercepted" by fighters.
By the way, you do know that the web site which you refer to is a conspiracy theory propaganda site for people who believe that the USA is responsible for every bit of evil in the world. It is neither impartial or truthful.