1.   As it came in to land, the plane tilted sideways.

2.   The plane tilted to port.

3.   As it came into land, the plane tilted sideways.

4.   That imbalance, left uncorrected, will cause the plane to tilt even more steeply.

5.   The agency said uneven ice built up on the wings could cause the plane to tilt to one side or the other.

6.   Then, the plane tilted twice more before leveling off.

7.   To see if this could cause the plane to tilt on its own, Greene flew it with a simulated ice shape different from the original testing.