Accident Overview
On November 25, 2012, at 1542 central standard time, a Beechcraft BE-35, registration N322D, made a forced landing to a field in De Ridder, Louisiana, following a total loss of engine power. The private pilot, who was the sole occupant and the aircraft's operator, sustained serious injuries. The airplane was substantially damaged. No flight plan was filed for the cross-country flight, which originated at Shreveport Downtown Airport (DTN), Shreveport, Louisiana, at approximately 1445, and was destined for Lake Charles Regional Airport (LCH), Lake Charles, Louisiana. Visual meteorological conditions prevailed for the flight conducted under 14 Code of Federal Regulations Part 91.
Flight and Forced Landing
According to the pilot, while cruising at an altitude of 5,500 feet, he heard an "odd" sound from the engine. Believing a catastrophic engine failure was imminent, he executed a 180-degree turn toward Beauregard Regional Airport (DRI), De Ridder, Louisiana. Attempts to smooth the engine operation were unsuccessful. The pilot then observed oil on the windscreen and smoke in the cockpit. He performed a gear-down landing in a field. Prior to touchdown, the pilot pushed the airplane's nose over to avoid a stall. The airplane landed hard in the field, sustaining substantial damage to the firewall, fuselage, wings, and tail section.
Post-Accident Examination
An on-scene examination by a Federal Aviation Administration (FAA) inspector revealed a 3-inch-wide hole in the top of the engine crankcase. The cap for the oil gauge rod (dipstick) was found several feet from the main wreckage. The salvage company reported that the bottom of the airplane was coated with oil, and oil drained from the airplane for several days after recovery.
On January 30, 2013, the engine was examined under the supervision of a National Transportation Safety Board air safety investigator. The examination revealed damage consistent with oil starvation. The #5 connecting rod had released from the crankshaft, and the #6 piston was damaged. The piston was fractured across the face, and the piston pin bore was fractured away from the back side of the piston. A large hole was observed in the crankcase above the #5 cylinder. No blocked or restricted oil ports, gallies, or slipped/elongated bearings were found. The main bearing support mating surfaces were intact with no signs of fretting or bearing tang-slot elongation.
The engine accessories, including the oil pump and filter, were removed and tested or disassembled. The oil filter element was contaminated with metal flakes, and a large amount of metal debris was found in the oil sump. No mechanical issues were identified with any of the accessories.
Examination of the dipstick cap revealed severe corrosion and missing lock-tangs that are used to secure it to the oil filler tube.
Maintenance History
The airplane's last annual inspection was performed on November 1, 2011, at a total airframe time of 4,797.4 hours.