CEN20LA301

Factual narrative

On July 22, 2020, about 1745 central daylight time, a Vans RV4, N54WP, was substantially damaged when it was involved in an accident near Idabel, Oklahoma. The airline transport pilot and a child passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he was on a multi-leg cross-country flight. On a planned refueling stop at Kennett Memorial Airport (TKX), Kennett, Missouri, the pilot noticed an oil leak coming from a chaffed oil line leading to the propeller governor. The pilot, with assistance from a local fixed base operator mechanic, removed the damaged oil line and replaced the line with a used serviceable oil line. After the installation and preflight, the pilot took off and climbed to 5,500 ft mean sea level, en route to his destination. About 70 minutes later, the pilot smelled something and observed oil on the windscreen. The pilot asked air traffic control for the nearest airport, which was about 11-miles away. As the pilot was maneuvering to the airport to land, the engine stopped producing power. About 1/2 mile from the airport, about 70 ft above the ground, the pilot attempted to maneuver the airplane to land on a roadway. The airplane impacted power lines and the ground. The pilot stated that he could not see the power lines through the oil-covered windscreen. The airplane came to rest in a ditch adjacent to the roadway, resulting in structural damage to the fuselage and empennage. Both occupants exited the airplane uninjured. Examination of the engine after the accident revealed a crack in the oil line leading to the propeller governor from its connection at the engine case. There was no clamp installed to secure the line. The experimental airplane had a conditional airworthiness inspection on May 1, 2020. According to Federal Aviation Administration Airworthiness Directive (AD) 90-04-06R1, a clamp should have been installed on the oil line leading to the propeller governor. The pilot reported that when he replaced the oil line at TKX, there was no clamp present, so he did not install a clamp and was not aware of the applicable AD. He also reported that had he been aware of the AD, he would have installed a new oil line and clamp. After a full stop landing to refuel on a cross-country flight in the experimental airplane, the pilot noticed a chaffed oil line leading to the propellor governor. The pilot, with assistance from a local mechanic, removed the damaged oil line and replaced it with a used serviceable line. The pilot pre-flighted the airplane, took off, and continued his flight. About 70 minutes into the flight, the pilot observed oil on the windscreen. As the pilot maneuvered for a precautionary landing at a nearby airport, the engine stopped producing power. About 1/2 mile from the airport, the pilot attempted to land on a roadway. The airplane impacted power lines and the ground. The pilot stated that he could not see the power lines through the oil-covered windscreen. The airplane came to rest in a ditch adjacent to the roadway, resulting in structural damage to the fuselage and empennage. Examination of the airplane and engine after the accident revealed a crack in the oil line leading to the propeller governor from its connection at the engine case. There was no clamp installed to secure the line. A conditional airworthiness inspection had recently been completed on the experimental airplane. According to Federal Aviation Administration Airworthiness Directive (AD) 90-04-06R1, a clamp should have been installed on the oil line leading to the propeller governor. The pilot reported that when he replaced the oil line, there was no clamp present, so he did not install a clamp and was not aware of the applicable AD. He stated that had he been aware of the AD, he would have installed a new oil line and clamp. The available evidence indicates that the pilot’s improper installation of the oil line resulted in the in-flight loss of oil and subsequent total loss of engine power. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

FAA avdata. C = Cause, F = Factor.

• — Personnel issues-Task performance-Maintenance-Installation-Pilot
• — Aircraft-Aircraft power plant-Eng oil sys (airframe furnish)-(general)-Incorrect service/maintenance
• — Aircraft-Fluids/misc hardware-Fluids-Oil-Related maintenance info