ERA25LA157

The mechanic’s inadequate annual inspection of the airplane and failure to comply with an applicable airworthiness directive, which resulted in a total loss of engine power due to oil starvation.

After an annual inspection on the airplane, the pilot was repositioning to his home airport. About 45 minutes into the cross-country flight, the engine rpm increased. The pilot reduced the rpm but about 5 minutes later the rpm increased again. The pilot tried to adjust the rpm again but the second time it would not adjust. He decided to land at the nearest airport but about 5 minutes later, the engine sustained a catastrophic failure, with engine parts exiting from the top of the engine cowling. The pilot glided to an airport and landed long and fast on a grass runway. The airplane departed the end of the runway and contacted a fence, resulting in substantial damage to both wings. Postaccident examination of the engine revealed that the oil filter adapter was loose, and the gasket was split open, which allowed the oil to leak out from the engine. The lack of oil likely resulted the propeller governor decreasing the propeller blade angle and increasing the rpm. The lack of oil to the crankshaft and bearing journals also likely resulted in heat buildup and fracture the Nos. 5 and 6 connecting rods due to oil starvation. The airplane’s most recent annual inspection had been completed about 1 month, and less than 5 operational hours before the accident flight. The engine and oil filter adapter installed on the accident airplane were the subject of an airworthiness directive (AD) that had been issued nearly 3 years before the annual inspection. The AD was prompted by previous losses of engine power due to oil starvation because the adapter vibrated loose and allowed oil loss. The AD required that the fiber gasket be removed and replaced with a copper gasket. Review of the airplane’s maintenance records revealed no evidence that the AD had been complied with. Had it been accomplished, the mechanic would have most likely removed the oil filter adapter, installed the new gasket, reinstalled the oil filter adapter, and tightened its associated hardware, which would have prevented the oil leak during the accident flight.

On February 25, 2025, about 1345 eastern standard time, a Beech E33, N7697N, was substantially damaged when it was involved in an accident near Lenoir, North Carolina. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, the airplane’s annual inspection was completed about 3.7 hours before the accident flight. During the annual inspection, the No. 6 cylinder was replaced due to low compression. The pilot subsequently departed from the Anson County Airport (AFP), Wadesboro, North Carolina, to return to his home airport, the Lake Cumberland Regional Airport (SME), Somerset, Kentucky. About 45 minutes after takeoff, at an altitude of 6,500 ft mean sea level, the pilot noticed the engine rpm increase. The pilot reduced the rpm with the propeller controller, but about 5 minutes later, the rpm increased again. The pilot tried to reduce the rpm again with the propeller control but the second time it would not adjust. He decided not to continue the flight over mountainous terrain, but to land at the closest airport, which was the Hickory Regional Airport (HKY), Hickory, North Carolina. Approximately 5 minutes later, the engine sustained a catastrophic failure, with engine parts exiting from the top of the engine cowling. The pilot glided the airplane to Lower Creek Airport (NC27), Lenoir, North Carolina; however, the airplane was too high and fast and landed long on the grass runway. The airplane skidded off the end of the runway and contacted a fence, substantially damaging the leading edges of both wings. An airframe and powerplant mechanic examined the engine after the accident and found that the oil filter adapter housing was loose, and the gasket appeared to have failed and split open, allowing the oil to leak from the engine. The Nos. 5 and 6 connecting rods were fractured from the crankshaft. The airplane’s most recent annual inspection had been completed on January 20, 2025. The airplane had accumulated 4.4 total hours of operation since the inspection. The Federal Aviation Administration issued airworthiness directive (AD) 2022-04-04, Continental Aerospace Technologies, Inc and Continental Motors: Amendment 39-21945, which became effective March 29, 2022. The AD was prompted by reports of two accidents that were the result of power loss due to oil starvation because the oil filter adapter vibrated loose and allowed the oil loss. The AD directed that the fiber gasket removed and replaced with a copper gasket. Review of the accident airplane’s maintenance records revealed no evidence that the AD had been accomplished.