I've been fretting about the details of UA93, the plane that went down near Shanksville PA when the hijackers abandoned their plan to crash into the US Capitol.
FIRST PROBLEM: although Todd Beamer and other passengers are legitimate heroes for their attacks on the hijackers, what did they think would happen if they killed all the hijackers ? None of the passengers were qualified to land that plane safely, so they were almost certain to crash in the end anyway.
SECOND PROBLEM: why did the hijackers take the plane down in open country? Surely a better option for them would be to land on a city and at least do Lockerbie-type damage. Probably much more since Pan am 103 was not guided into the ground.