History of Flight
On August 27, 2019, about 1206 central daylight time, a Beech V35 airplane, N6245V, was substantially damaged when it was involved in an accident near Monroe, Wisconsin. The private pilot sustained minor injuries and the passenger sustained serious injuries. The airplane was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
The pilot and passenger were about 48 minutes into an instrument flight rules (IFR) flight when the engine suddenly lost oil pressure. The pilot, in communication with air traffic control, declared an emergency and reported an oil pressure event that appeared to be building back up. He requested a deviation to a nearby airport. The controller instructed a descent and issued a heading of 050° toward the airport. After the pilot indicated no further assistance was needed, the controller terminated radar services. The pilot then canceled his IFR flight plan. Subsequently, engine oil covered the windshield and smoke entered the cabin. The pilot switched to the diversion airport's common traffic advisory frequency and spoke with a pilot who had just departed.
ADS-B data showed a shallow descent directly toward the diversion airport until the data ended about 1.5 nautical miles southwest of the airport at about 3,200 ft above ground level. The pilot reported being unable to locate the airport due to smoke and oil, and after realizing he had passed it, he chose a forced landing site on a rural road but diverted to a cornfield due to power lines, resulting in a hard landing.
Aircraft and Maintenance
Maintenance records indicated the engine underwent a major overhaul in 1993 at 2,001 tachometer hours, with new Continental Motors cylinder assemblies installed. In December 2012, at 693.2 hours since major overhaul (SMOH), the engine was removed after an oil starvation event caused by a broken oil line. The engine was disassembled, cleaned, inspected, and repaired; the crankshaft and main and rod bearings were replaced. After repair in February 2013, the engine accumulated 1,189.56 hours SMOH through four annual inspections. The final maintenance entry was an oil and oil filter change on June 25, 2019, at 1,882.76 hours SMOH. Records of 27 engine oil analyses from 2009 to 2019 were all normal, including one taken 33.6 hours before the accident. The JPI EDM 830 data monitor was removed but no data could be recovered.
Wreckage and Impact
The airplane impacted a mature cornfield, rotated 180°, slid backward, and came to rest upright. The fuselage remained intact; the engine was impact-separated from the firewall. Both wingtips sustained impact damage. An FAA inspector noted a hole in the top of the engine crankcase above the No. 6 cylinder. The oil filter was secure and oil lines were intact. Nos. 5 and 6 cylinder connecting rods were broken, preventing engine rotation. Repeated impact marks were found inside the case near those cylinders. Nos. 1–4 connecting rods remained attached but showed heat distress from lack of lubrication. Nos. 5 and 6 connecting rods had fractured at the crankshaft bearing end and sustained damage from impacting the crankshaft, cylinder walls, and case interior; their bearings were not identified in the debris. Both rods showed heat damage and lack of lubrication. Nos. 5 and 6 pistons remained attached via piston pins.