What happened
The DC-3C departed from runway 10L and immediately performed a right turn, followed by a left turn directed back toward the airport. During this maneuver, the crew declared a fire aboard the aircraft. The flight occurred at night under visual meteorological conditions. Witnesses reported seeing an orange glow or flames emanating from the right engine.
Approximately 10 seconds before impact, the first officer broadcasted over the tower frequency that the aircraft was going to stall. While the aircraft was executing a left turn toward runways 28L and 28R, the right wing struck the ground, causing the aircraft to cartwheel to a stop. A postcrash fire occurred, destroying the inboard right wing and the cockpit area.
The investigation
Investigators located small aluminum fragments from the aft edge of the right engine accessory cowling on the ground just short of the impact site. While these fragments showed signs of heat distress, they did not show significant melting. An examination of the right engine and its accessory section found no evidence of a fire occurring prior to impact, and there was minimal sooting or metal splatter on the leading edge of the right horizontal stabilizer.
Spectral analysis of radio transmissions indicated no significant divergence in engine RPM between the two engines. Postcrash examination of the propellers showed blade pitch angles of approximately 18-19 degrees for the right propeller and 30-32 degrees for the left propeller at the time of impact. Analysis of the propeller slash marks from the right propeller indicated an RPM range of approximately 1750 to 2570 at speeds between 68 and 100 knots.