Four passengers with fake passports, could have been a hijacking. That’s all I can think of why a terrorist would need four people on board, to take over the plane. Remember, when the first plane hit the World Trade Center the media was reporting it to be a “Horrible accident” it wasn’t until the second plane hit the second tower that the light bulb went off that we were under attack. I think each plane had what, 3-4 hijackers on board
19 hijackers (iirc) four planes.
5 on 3 of them,4 on the fourth one.
You really need to tabulate the number of flights vs the number of passengers on said flights who had fake passports.
IOW, given a flight with passengers presenting passports, how likely is it to crash due to terrorism, vs given a flight with x number of passengers presenting fake passports, how often does it crash due to terrorism?
Then, of course, there are other considerations. Where did the flight originate? Where was it headed? How many of each nationality were aboard? And who might wish to risk pissing off whom by destroying the flight? My understanding is, most of the PAX were Chinese. That country doesn't waste energy worrying about nonsense like multiculturalism and political correctness.