What happened
On June 14, 2021, at approximately 12:30 EDT, a Diamond DA20-C1, registration N458MA, was involved in an accident near Matthews, Virginia. The aircraft was being operated by American Aviation LLC for a Part 91 instructional flight.
During a short cross-country flight toward Tangier Island in the Chesapeake Bay, air traffic control instructed the crew to descend from 5,500 feet MSL to 2,500 feet MSL to avoid an active military operations area. After the student pilot leveled the aircraft at the new altitude, the flight instructor noted engine roughness and vibration. The instructor attempted to correct the issue by increasing the throttle from 1,900 to 2,200 RPM, but the engine began shaking violently before experiencing a total loss of power.
Determining there was insufficient altitude to reach land, the flight instructor ditched the aircraft in the Chesapeake Bay near a fishing trawler. The flight instructor and student pilot sustained 2 minor injuries and were subsequently rescued.
The investigation
The wreckage was recovered approximately two weeks after the event. An examination of the engine revealed that the oil sump drain plug was missing. Additionally, the number 1 and number 2 connecting rods were found to be fractured in a manner consistent with oil starvation.
Maintenance records indicated that a 100-hour inspection had been completed only 4 days and 9.3 operating hours prior to the accident. While the mechanic responsible for the inspection stated that the drain plug had been torqued and secured with safety wire, the physical evidence suggested otherwise.