What happened
While cruising at 11,500 feet between Burbank and Hawthorne, the DC-3 experienced a failure of its number two engine. In response to the malfunction, the crew shut down the engine and feathered the propeller. At 20:50 EDT, the flight crew contacted Tonopah, NV, to request an emergency landing at that location.
Shortly after, at 20:58 EDT, the number one engine also lost power. Because the propeller could not be feathered, the aircraft entered an emergency glide toward the Mud Lake airfield. To maintain an airspeed of 110 knots, the aircraft descended at a rate of 2,000 feet per minute. During this descent, the aircraft suffered a total loss of both hydraulic and electrical power.
The aircraft impacted the ground with a nose-down attitude of approximately 10 to 20 degrees during the flareout phase, which caused the plane to overturn.
Findings
Investigations revealed significant maintenance discrepancies. The aircraft's cylinders had been improperly installed, and there were issues with incorrectly adjusted voltage regulators and valve clearances. Furthermore, it was noted that all maintenance work had been conducted by third-party companies rather than the operator, and many service records were found to be incomplete or insufficient. The electrical system, which utilized two 28V DC generators and one 12V battery, contained components designed for 12V operation, excluding the starters.
The primary cause of the dual engine failure was identified as a fatigue failure involving the right engine's number 12 cylinder and a failure of the left front master rod bearing.