Accident Details
On July 21, 2023, at approximately 1350 central daylight time, a Van's Aircraft RV-10 amateur-built experimental airplane, registration N730WL, sustained substantial damage during an accident near Chouteau, Oklahoma. The pilot and the passenger received minor injuries. The airplane was operated under Title 14 Code of Federal Regulations Part 91 as a personal cross-country flight.
The flight's purpose was to transport the two occupants to the Experimental Aircraft Association AirVenture at Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The aircraft made an intermediate stop at Muskogee-Davis Regional Airport (MKO), Muskogee, Oklahoma, where it was refueled with approximately 35 gallons of 100 low lead fuel.
Sequence of Events
After departing to the north and establishing cruise flight at 6,000 feet, the pilot—who also owned the airplane—noticed a red warning light illuminated in the cockpit. He observed that the oil pressure gauge was "pegged" at 320°F. The pilot immediately reduced engine power and initiated a glide profile to "take all the load off the engine" to allow it to cool.
Deciding to land at the nearest airport, Mid-America Industrial Airport (H71) in Pryor, Oklahoma, the pilot began setting up for an approach to runway 36. During this approach, the engine "seized up" and experienced a total loss of power. The pilot performed a forced landing to a flat grass field approximately 3 miles south of the threshold of runway 36. The airplane came to rest upright, and both occupants egressed without further incident. The accident resulted in substantial damage to the fuselage and both wings.
Examination and Findings
The airplane was recovered from the field, and the experimental General Motors LS-3 (V-8) automotive engine was examined. The examination revealed that the positive crankcase ventilation (PCV) valve had failed for undetermined reasons. According to the pilot, the failed PCV valve caused the engine to suck "too much oil" out of the crankcase and into the intake section. He further reported that during the "long slow climb" to 6,000 feet, this oil loss led to the oil level becoming "too low," causing the oil to overheat. Once the oil overheated, the engine ceased operating.