Washington, D.C. ? Flight data point to possible flight crew errors rather than ice accumulation as a key factor in last month’s plane crash near Buffalo, N.Y., that killed 50 people, aviation safety experts said Wednesday.

The National Transportation Safety Board said information obtained from the craft’s data recorder shows the stall warning system had activated before the accident and there was some ice accumulation, but no mechanical problems were found with the plane.

Continental Connection Flight 3407 was about five miles short of the Buffalo Niagara International Airport, flying in icing conditions the night of Feb. 12 when the plane tumbled out of control and plummeted onto a house.