Flight History
The pilot was conducting the third round-trip of a Part 135 cargo flight. The first round trip began the previous evening at about 2150, with an approach and landing on runway 15R at 2305. The second round trip ended with an approach and landing on runway 28 at 0230. Prior to the third approach back to the airport, the pilot was cleared for and acknowledged a visual approach to runway 33R twice, at 0720 and at 0721.
Accident Sequence
Instead of proceeding to runway 33R, the airplane flew north of it on a westerly track consistent with a modified downwind for runway 15L. During the westerly track, the airplane descended to 700 feet. Just before reaching an abeam position for runway 15L, the airplane made a sharp left turn back toward the southeast and descended into the ground.
Witness Observations
Witnesses reported the airplane's movements as "swaying motions as if it were going to bank left, then right, and back left again" and "the nose...pointing up more than anything...but doing a corkscrew motion." Other witnesses noted "wings straight up and down" and "wings vertical." Tower controllers observed the airplane as "low and tight" and "in an unusually nose high attitude close to the ground." It then "banked left and appeared to stall and then crashed."
Aircraft Examination
A post-flight examination of the wreckage revealed no evidence of mechanical malfunction.
Pilot Background
The pilot reported 6,800 hours of flight time. He had flown multiple round trips the previous two evenings. He checked into a hotel at 0745 on the morning prior to the accident flight, checked out at 1956 the same day, and reported for work about one hour before the first flight began.
Probable Cause
The probable cause was the pilot's failure to maintain airspeed during a sharp turn, which resulted in an inadvertent stall and subsequent impact with terrain. Factors included the pilot's failure to fly to the intended point of landing and his abrupt course reversal back toward it.