Why they say american 11 was still in the air and didnt hit wtc?

What I was referring to is that "blips" are not inserted into any FAA radar system. I cannot speak for NEAD or any military, but I also don't believe they "insert blips" into any of their systems. During the many exercises I have been involved in, if there is to be any type of live "enemy" this role is often played by a contract company that flies Lear Jets as the "targets". During any exercises that may involve real intercepts, the FAA has controllers that serve as "trusted agents"; they know who the flights are, what their flight paths are, any other identifying information. These people will not reveal any information to the exercise participants but if there is a safety need to notify the participants (in the air or on the ground) of the actual information, the "trusted agent" is the person the military goes to.

Many of these exercises don't really involve many actual aircraft, but are done as a "table top" exercise, where a lot of the exercise progresses like a board game. In exercises in which there are actual assets in the air, the exercises are done off of the coast, in the military "Warning Areas". ANY flights that may be planned to fly over land are tightly restricted to very well-defined routes, corridors, restricted areas, etc.

In other words, the party responsible for the Nation's national airspace, the Federal Aviation Administration, has complete control and knowledge of all exercise details.

No phantom "blips" are generated.

Except in a small number of very well-defined and well-controlled areas is any actual live fire done. In most exercises of this scale, of which there are quite a few every year, aircraft are NOT even armed.

No one understood the significance of the first 2 aircraft being lost on radar. Losing aircraft targets, especially 14 years ago, was not uncommon. Transponders fail. Air traffic sectors above 18,000 feet do not monitor "raw radar", as all aircraft above 18,000 feet are required to have operating transponders for tracking. When a transponder would fail, a controller would push a button to display "raw radar". This presents a lot of clutter, from ground, from weather, even from large flocks of birds. A controller would start from the last known position of the aircraft, then look forward along the route of flight the aircraft was supposed to be flying. Eventually a controller would identify a "primary target" (the raw radar return) that appeared to be the flight with the inoperative transponder. Via position reporting and verification between controller and pilot, positive identification is reestablished. Or a controller would issue a 30 degree turn to the pilot, then observe the target executing that turn. This would also provide positive identification.

In a circumstance of a transponder being turned off, the flight veering well off of its filed route, and loss of radio communications, it gets very difficult to determine the position of an aircraft. Though not common, this would happen on occasion before 9-11. There were procedures that provided a safe path for the aircraft until communications and/or radar identification were re-established. Back in 2001, a worst-case scenario that was expected was that the aircraft crashed.

The first 2 aircraft disappeared from the scopes and radios at different ATC facilities. There was no immediate way for anyone to put 2+2 together to understand what could have been occurring. When the first aircraft flew into the WTC, it took some time and communications to realize that this was one of the missing airliners. When the second one hit, it became clear to all authorities what was happening.

Sometime during that point, the other 2 aircraft had their transponders turned off and communications from the cockpit ceased. The FAA was frantically trying to determine how many other aircraft might be involved. In addition to #3 and #4, there were a number of other aircraft in the system that had lost communications with the FAA. I believe the number was greater than 6, but less than 12. Again, given the technology, this was NOT uncommon. Communications were always reestablished, but it sometimes took many minutes to do that.

#3 slammed into the Pentagon. By that time, #3 had been tentatively ID'd, but not before it was too late to take any action. #4, UAL93, was the one aircraft that was positively IDd as being hijacked, its location somewhat pinpointed, and a threat assessment placed the potential target to be downtown DC.

So why no military intercept? The participants in the military exercise were neither armed not anyway near where #s 3 and 4 were. The closest military unit that could be scrambled was at Andrews, and the planes were not armed nor ready for an immediate response. 2 fighters were launched with the intention of ramming the airliner. However, there are discrepancies in the accounts as it appeared the DC Air National Guard unit did not learn that UAL93 was hijacked until after it had crashed.

You have to remember that in 2001, the existential military threat was Russia. All air defenses were trained and position to defend from an external attack. There had never been any significant thought regarding attacks from within our borders.

"Vigilant Guardian" was just a normal military exercise that really had no bearing on what may or may not have happened. If anything, many serious investigations have concluded that because the exercise was occurring, NORAD's responses were possibly quicker than if there was no exercise. All of the information in that link to the conspiracy site is just a bunch of background noise. All of that can be written in a way to sound suspicious, but in-depth analysis shows that that information is just superfluous to what the reality of the events were.

Many of the problems in communications, procedures, etc., that occurred during 9-11 (aviation-wise) have been addressed. Were there to be another event like that, recognition and response would be much quicker and more effective.

The US experienced something that had never happened before, was not prepared for and did its best, at that time, in dealing with the confusion.