Just some observations regarding the level of detail and planning that went into this attack. I'm posting again a link posted earlier in the thread for reference, that contains the flight tracks and time details for each flight.
http://www.washingtonpost.com/wp-srv...jack091101.htm
1. All 4 aircraft involved shared the same type rating (757/767 - as many have pointed out). This would make organization of this attack much easier by possibly allowing some of the suicide pilots with training to train others. All pilots would have been working with the same systems, and all would be on the same "page". This would also require the "penetration" of only one flight school for sim training or other training.
2. All flights originated on the east coast, bound for west coast destinations. Since all "targets" were east coast targets, that means all aircraft were fully loaded with fuel for their transcontinental flights, and arrived at their targets with substantial fuel loads, thus making the aircraft better bombs. All 4 flights also took off within 12 minutes of each other (see the link).
3. Each aircraft seems to have been "assigned" to its particular target based on that aircraft's size and fuel load. As we know, two 757s and two 767s were involved. Both 767s were "assigned" to the World Trade Center Towers, each was in the air for about an hour (more or less) before impacting the buildings, thus arriving at their targets with large (and comparable) fuel loads. The 767s were chosen for the WTC towers I believe because they were the largest structures attacked, and had the best chance of bringing the towers down.
While the Pentagon is a very large building, I don't think it's realistic (if I can use that word while discribing an unworldy scenerio) to take out the entire building in a single plane crash. That's why I think a 757 was chosen for that building.
4. The time coordination for all flights was very well planned. Both 767s (AA-11 and United-175) departed BOS Logan within a minute of each other, both bound for LAX. The flight paths followed by each aircraft however were very different. I think this was designed partly to confuse the ATC centers and the FAA. Maybe someone can confirm if the flight paths followed, actually caused the aircraft to be handled by different ATC centers. Partly this also allowed the aircraft to arrive at the WTC towers about 20 minutes apart, thus allowing the smoke to clear enough from the first impact to allow success with the second impact.
The timing of the impact with the Pentagon occurred 35 minutes after the second impact at the WTC. Did they plan for the Pentagon to be full of military personel responding to the WTC impacts, by the time of this attack? Was the initial flight path of AA-77 towards the White House a possible diversion to prevent advanced notice and possible evacuation of the Pentagon? I can't think of any other reason for the fighter like hard course change into the Pentagon.
The last aircraft, United-93 was on a direct flight path to Washington D.C. from its course change at Cleveland, when it went down in Penn. It crashed at 10:10, maybe about half an hour from D.C. This aircraft would have arrived in D.C. with the lightest fuel load of all the attack aircraft. I think that this aircraft might have been "assigned" to the White House, as it would have been the smallest structure of those attacked, and maybe the terrorists thought a 757 with a lighter fuel load would have been enough for this building. Maybe the timing of its impact with the White House roughly an hour after the attack on the Pentagon, was designed to catch government personnel rallying at the White House after the Pentagon attack. I don't know, that's just a guess.
5. Finally, it would take some pretty good flying to perform all of this, with good navigation, some knowledge of ATC procedures, hand flying into the target buildings, and controlling the time of arrival at the targets. The pilot Tim Timmerman who saw the attack at the Pentagon, said that aircraft came in low and impacted the parking lot just in front of the Pentagon wall, dissipating some of its energy. He said the wings separated forward, the cockpit section broke off, and the whole mass plowed into the side of the building. The aircraft apparently struck some light poles on its low approach into the Pentagon.
That low approach (under the radar) and 270 degree high banked turn suggests to me someone with a military aviation background may have been flying AA-77, but I could be wrong. It's also possible that since United-93 was the last of these 4 aircraft remaining in the air, that news of what happened at the WTC and the Pentagon may have reached some of the passengers (via cell phones or other means). If they knew what was happening, then someone on board may have taken action to stop this flight, since they were fully aware that they were being hijacked.
God, what an awful thing. Trying to work out some the details is just my way of dealing with something like this. My thoughts and prayers have gone out to all who are involved. May God bless my nation at this terrible time.