Complex sentence: On December 7,1983, N57901 was destroyed when it Collided with Black Mountain, after pilot Paul Kinsey attempted an Auto-rotation after the left engine cowling came apart mid flight.
Split into simpler sentences: On December 7,1983, N57901 was destroyed when it Collided with Black Mountain. Pilot Paul Kinsey attempted an Auto-rotation after the left engine cowling came apart mid flight.