What happened
During the initial climb following departure from runway 09, the aircraft entered a left-hand turn. At an altitude of approximately 1,000 feet, the right engine experienced a backfire and visible flames, resulting in a loss of power. In response, the captain directed the co-pilot to feather the propeller on the number two engine. While the co-pilot activated the feathering button, the mechanism failed to remain engaged when the button was released during subsequent gear and flap extensions.
As the aircraft approached the landing area on a left downwind pattern at an altitude of 500 feet and a speed between 95 and 100 knots, the captain turned toward the runway. An attempt to perform a go-around was initiated by increasing power on the left engine without a corresponding increase in propeller speed. Following a right-hand turn, the aircraft crashed roughly three miles from the runway.
Findings
Post-accident investigations revealed that the propellers were in an unfeathered state at the time of the crash. While the engine failure procedure required moving the fuel selector to the 'OFF' position, the right engine fuel selector was found in the main tank position. Physical examination of the right engine identified a crack in the number 11 cylinder. Evidence of fire, including soot, scorching, and a burn-through area on the underside of the engine cowling, was located near this cylinder.
Although the co-pilot noted a prior issue regarding the propeller feathering system, there were no documented discrepancies related to this malfunction in the aircraft maintenance records. The aircraft was operating below the recommended single-engine speed of 85 knots during the critical phase of the maneuver.