Accident Overview
On May 16, 2021, at approximately 1545 Pacific daylight time, a Cessna 210 airplane, registration N7350E, sustained substantial damage following a forced landing near Lake Arrowhead, California. The pilot and passenger on board were seriously injured. The flight was conducted as a personal operation under Title 14 Code of Federal Regulations Part 91.
Flight and Engine Failure
The pilot reported that while climbing through an altitude of about 8,500 ft mean sea level (msl) en route to Big Bear Airport (L35) in Big Bear City, California, he noticed a partial loss of engine power. He contacted air traffic control and received information about alternate airports and current weather. While over mountainous terrain, the engine subsequently lost total power. Believing he did not have sufficient altitude to clear rising terrain, the pilot initiated a forced landing to a clearing on sloped terrain. The airplane collided with vegetation during the landing and came to rest upright on the steep slope.
Postaccident Examination
Postaccident inspection revealed substantial damage to both wings and the fuselage. Examination of the engine components showed that the upper and lower spark plug electrode areas were black in color. Further investigation of the fuel flow manifold valve, throttle body/fuel control, and engine-driven fuel pump identified a malfunction of the fuel flow manifold valve plunger, which prevented normal operation. When the fuel flow manifold valve was connected to a test stand and fuel pressure was applied, the valve failed to open. Disassembly of the valve revealed tooling marks on the plunger, a deformed seal that was not seated flat on the manifold body, and a diaphragm spring longer than a normal spring. Tooling marks on the plunger were documented in Figure 1 of the report. The plunger assembly and diaphragm were substituted in the fuel flow manifold valve, after which the valve performed within manufacturer specifications when retested.
Maintenance Records
A review of the airplane’s maintenance records could not determine if any maintenance had been performed on the fuel flow manifold valve.
Conclusion
No probable cause was stated in the investigation source.