Incident Overview
While in cruise flight, the pilot encountered a series of equipment failures within a short timeframe. The number one radio stopped functioning, followed by the number two radio, and then the transponder. These failures occurred within five minutes. The pilot became uncertain of his position and grew concerned about decreasing visibility and impending darkness.
Pilot Actions
After the equipment failures, the pilot initiated a descent and began following a freeway. He reported that all the instruments on the right side of the panel then went out, followed two minutes later by the left side panel instruments. While flying through a valley, he saw the words "San Bernardino" on a building, leading him to conclude he was east of his intended track. He spotted an airport and considered a precautionary landing but deemed the runway insufficient in length. Instead, he selected a dirt road near the freeway. Concerned about stalling, he added 10 knots to his approach speed.
Outcome
Upon landing on the dirt road, the pilot braked hard to avoid entering an intersection. The aircraft struck a wooden pole, veered off the road, and ended up in a ditch. The operator later reported that the alternator had gone off-line during the flight.