Accident Overview
On December 21, 2023, at about 1653 mountain standard time, a Diamond Aircraft Industries DA 40, registration N453DS, was substantially damaged in an accident near Spanish Fork, Utah. The pilot and passenger were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
According to the pilot, he and his brother departed Spanish Fork Municipal Airport (SPK) for a local flight lasting about 36 minutes. While approximately 5 miles west of SPK at an altitude of about 10,500 ft mean sea level, they heard a loud sound and observed something departing through the top of the engine cowling. The engine subsequently ran rough, and smoke emanated from the engine area. The pilot noted the oil pressure had dropped to zero and the audible oil pressure alarm had activated. He turned the fuel selector valve to OFF, pulled the mixture to idle cutoff, and opened the window to clear thick smoke during an emergency descent. During the descent, sparks and metal pieces were ejected from the engine cowling. The pilot configured the airplane for landing; upon touchdown on runway 12, the nosewheel collapsed. The pilot and passenger exited unassisted. The pilot observed flames coming from the airplane but did not attempt to extinguish the fire. A postaccident photo showed the entire engine and cabin area engulfed in flames.
Engine Examination
Postaccident examination of the engine revealed the engine case was fractured into multiple large sections, exposing internal components. The left magneto was not secured and had separated from the magneto mounting pad. The left magneto mounting hardware and hold-down clamps remained on the mounting studs but were near the ends with no stud threads exposed beyond the nuts. The magneto mounting flange and pad did not exhibit damage that would have allowed the magneto to separate.
Further examination showed damage to the valvetrain, including a fractured camshaft. The rotating and reciprocating group sustained fractured connecting rods, scored and fractured pistons, and damage to all but one bearing journal, consistent with frictional forces from inadequately lubricated bearing surfaces. The oil filter contained metallic debris of phosphor bronze material, consistent with bearing material.
The pilot reported that during the preflight inspection, the oil level was just above the 6-quart line.
Maintenance History
Review of maintenance logbooks indicated the left magneto was replaced on December 20, 2023, though the writeup was incorrectly dated December 21, 2023. The Director of Maintenance stated he replaced the left magneto the day before the accident, using new hardware secured to the required torques. According to the operator, the airplane had flown about 4.9 hours with the new magneto. The accident flight lasted about 36 minutes.
Postaccident Airframe Examination
The postaccident airframe examination revealed that the fire thermally damaged the airplane from the engine nacelle to the aft section of the cockpit and from the root of both wings outboard about 6 ft. Examination of the remaining airframe found no evidence of a mechanical malfunction or failure that would have precluded normal operation.