I. M. Esperto
Dittos to Newswatcher.
Possibility 5. Carbon monoxide leak. Pilot passes out at controls. Happened to a friend of mine (that or they theororize he may have fallen asleep.)
Bonanzas are used for check-hauling and if it was day light, this pilot may have been up for many hours. Perhaps fatigue and CO.
I think any pretext to a dry run for terrorists is off the mark. It would only spark TSA interest.
Make no mistake though, terrorists will try to use aircraft again. Was this crash followed by a big explosion? 500lbs of Semtex could do a lot of damage. If there was no massive explosion, I'm inclined to think it was not Al Khaeda.
PT