Accident Overview
On May 28, 2018, at about 2015 central standard time, an experimental, amateur-built RV-8 (registration N214FF) was substantially damaged during an accident near Somerset, Wisconsin. The private pilot and a passenger received minor injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Events Leading to Accident
According to the pilot, approximately 10 miles from the intended destination airport, the sky became dark with lightning and increasing wind. He decided to divert to his private grass runway. Shortly after, the airplane's radio and GPS unit began to flicker and then went completely dark, followed by a total loss of engine power.
Pilot Actions During Emergency
The pilot attempted to troubleshoot the loss of engine power. He stated that the mixture was at full rich and the electric boost pump was on. He noticed that the switch light on the electric boost pump was very dim and there was no response when he flipped the switch. He tried pumping the throttle and changed the fuel selector from the left to the right tank, but engine power was not restored.
Forced Landing and Damage
As the pilot continued to lose airspeed and altitude, he selected a field for a forced landing. During the landing, the airplane's right main landing gear impacted a fence, resulting in substantial damage to the wings.
Post-Accident Examination
A Federal Aviation Administration (FAA) inspector examined the airplane after the accident. The inspection revealed that the main battery was a homemade gel-cell battery with a bundle of small, melted wires attached to the positive battery post. One of the wires in this bundle was connected to the engine's electronic ignition system. A backup battery was mounted to the engine firewall with a spade connector wire lead, which was disconnected. This wire connected the electronic ignition to the backup battery. The backup battery was tested with a voltmeter and was found to be fully charged.