CEN23LA327

The amateur-built experimental airplane was in cruise flight when the pilot noticed that a red warning light in the cockpit was illuminated. 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” so it could cool down. While setting up for the approach to land at the closest airport, the engine “seized up” and sustained a total loss of power. The pilot performed a forced landing to a flat grass field. The airplane sustained substantial damage to the fuselage and both wings. Postaccident examination of the experimental automotive engine revealed that the positive crankcase ventilation (PCV) valve had failed. The pilot reported that the failed PCV valve caused the engine to suck “too much oil” out of the crankcase and into the intake section. He additionally reported that over the “long slow climb” to the cruise altitude of 6,000 ft, this caused the oil level to get “too low,” eventually causing the oil to overheat, and that once the oil overheated, the engine then stopped operating.

On July 21, 2023, about 1350 central daylight time, a Van’s Aircraft RV-10 airplane, N730WL, sustained substantial damage when it was involved in an accident near Chouteau, Oklahoma. The pilot and the passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal cross-country flight. The purpose of the flight was for the two occupants to travel in the amateur-built experimental airplane to the Experimental Aircraft Association AirVenture at the Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The airplane stopped at the Muskogee-Davis Regional Airport (MKO), Muskogee, Oklahoma, where it was refueled with about 35 gallons of 100 low lead fuel. The airplane departed to the north and, after being established in cruise flight at 6,000 ft, the pilot, who is also the owner of the airplane, noticed that a red warning light in the cockpit was illuminated. He noticed “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” so it could cool down. The pilot decided to land at the closest airport, which was the Mid-America Industrial Airport (H71), Pryor, Oklahoma. While setting up for the approach to runway 36, the engine “seized up” and sustained a total loss of power. The pilot performed a forced landing to a flat grass field about 3 miles south of the threshold for runway 36. The airplane came to rest upright, and both occupants were able to egress from the airplane without further incident. The airplane sustained substantial damage to the fuselage and both wings. 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. The pilot reported that the failed PCV valve caused the engine to suck “too much oil” out of the crankcase and into the intake section. He additionally reported that over the “long slow climb” to the cruise altitude of 6,000 ft, this caused the oil level to get “too low,” eventually causing the oil to overheat, and that once the oil overheated, the engine then stopped operating.