Among unanswered questions are why the plane made a slow turn to the south, away from the airport, and why it descended at a steeper-than-normal angle, before crashing into the woods. Witnesses have said the plane seemed to be flying low and sounded like it might be in trouble. Investigators have said the plane's last known airspeed was 85 knots, close to stall speed. from AP via NY Times. I'd say that these facts are completely consistent with my poison gas theory or something else that incapacitated the pilots quickly. I'll have to reinstall Flight Simulator on my computer and try preparing for a landing--flaps and gear down, trying to line up on the runway, and then just stop controlling the plane and see what happens. I think that a slow continuation of an already-started turn, followed by a stall leading to a steep dive to a crash, is a realistic possibility. The scenario of the Wellstone crash seems inconsistent with a major mechanical failure. If there was engine trouble, the pilots would have radioed in a mayday and asked for help in locating a road or field to land on if they couldn't make it to the airport. If they lost directional control of the plane, as the wide turn might suggest, they would have responded by adding throttle to gain altitude and buy time, and they would have radioed in the situation. The airliner that crashed in Iowa in 1989 lost most directional control (ailerons and rudder), but used different throttle settings on the left and right engines to steer the plane, with some success, towards an airport. It certainly seems to me that Wellstone's plane simply lost its sense of direction--that is, the pilots were incapacitated somehow. And it is hard to imagine that happening to both pilots at the same time unless foul play was involved. An alternative to the poison gas would be a suicide terrorist among the staff or the pilots.