There was some very small (compared to a jumbo jet) craft that hit the pentagon, some say missile.
The wreckage does not support large passenger jet.
Same thing could have happened in shanksville, but whatever it was- it was headed to Bld 7, and was shot down by Major Rick Gibney who disobeyed orders and broke the sound barrier. (so NORAD had ordered him to drive in the slow lane and the attack would have succeeded.)
BTW: NORAD needs a good cleaning too Q!