The pilot was conducting a local personal flight in the experimental, amateur-built Zenith CH-601. During cruise flight, the voltmeter’s indications became erratic and shortly after the airplane experienced a total loss of electrical power.
The engine subsequently lost power, and the pilot conducted an emergency landing near Ocean Shores, Washington, during which the bottom of the fuselage contacted surrounding vegetation.
The right wing then dipped, and the airplane hit terrain.
The pilot reported that, following the accident, he checked the battery’s charge, and it was 11 volts. The electrical system on the airplane required 12 to 13 volts for operation.
The pilot partially disassembled the airplane following the accident, and the engine, most of the flight instruments, the tachometer, and the interior components were not available for examination. Therefore, a thorough evaluation of the airplane’s electrical system was not possible.
However, the battery examination revealed that it had a 10-volt charge, indicating that either a battery or charging system failure occurred.
The fuel delivery system included two electronic fuel pumps connected in series with no mechanical or auxiliary pumps installed. Therefore, the loss of electrical power would have disabled both fuel pumps and resulted in fuel starvation and a loss of engine power. There was no other method to deliver fuel to the engine if the battery power was insufficient to power the fuel pumps.
Probable cause: A reduction in electrical power, which disabled both fuel pumps and resulted in fuel starvation and a loss of engine power.
NTSB Identification: WPR16LA164
This August 2016 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.