I stole these comments from an aviation website and I would have to think one of these two things caused the stall which led to their demise! 

"It also has a stick shaker near stall and a pusher at the stall. To stall a PC-12 with landing flaps, you have to really work at it. When the PC-12 first came out, there was a crash due to a split flap condition. One side came down, the other did not. The aircraft rolled inverted and crashed. After that, Pilatus instituted a split flap sensor. In the event of a split flap condition, the flaps become inop. I haven't heard of a split crash crash after that.

Food for thought."

"And the accident appears to be a textbook case of tailplane icing as the pilot lowered the flaps to the landing position."

Icing sucks
Author:I agree with your last sentence 3/24/2009 2:39:52 PM Reply to: 994623	Basically the same damn thing happened to the Continental crew.