[sc_rufctr]

I'm just glad the pilots didn't have to make that decision and it was completely out of their hands.

The war against terror began on that flight and the people that fought back are heroes in the truest sense of the word.

As far as were they should aim. I'm guessing they would have rehearsed for such a scenario.
IMO... There would be a formal US military assessment of each commercial air craft and were they should aim to bring it down.
These are not hardened military planes. The fuel tanks seems the most logical place to me.