[TomGuy]

IIRC, Moussoui (the so-called 20ieth hijacker) said one time that there were 5 teams who were supposed to hijack planes that morning.

If true, then the 5th team failed to act and disappeared into the throngs of passengers.

[TruthWillWin]

Perhap he was supposed to be the fifth hijacker for Flight 93 that only had 4.

[null and void]

IIRC, Moussoui (the so-called 20ieth hijacker) said one time that there were 5 teams who were supposed to hijack planes that morning.

I'd be willing to bet Moussoui's team wasn't the only one. OBL and his ilk are smart enough to not put all the eggs in one basket. Operating separate cells is SOP for these guys.