[Lucas1]

News is reporting that the pilot sent a message to control tower saying he was having problems navigating the plane and sent out an SOS - so there you have it - it was a very freak accident. Not a terrorist attack of any form. It happens - rare but it happens

[newsperson999]

Well if I was a terrorist and wanted to get my plane into a downtown area without getting shot down I would say I was having engine trouble too.

[nemo]

If the pilot did not want to get shot down before hitting his target, wouldn't it make sense for him to broadcast an SOS?

[Diddle E. Squat]

Yeah, and some of the 9/11 terrorists told ATC things to make it appear normal. I'm not ruling out anything just yet.

[Stefan Stackhouse]

News is reporting that the pilot sent a message to control tower saying he was having problems navigating the plane and sent out an SOS

The question still to be answered is: WHY was he having problems navigating the plane?

I know it sounds far fetched, but is there any credible scenario where a terrorist would covertly rig up a private plane like this one so that a terrorist on the ground could override the pilot controls and fly the plane by remote control into the building?