Background
The pilot received a weather briefing that forecast instrument flight rules (IFR) conditions after 1800 EST. He departed from Washington National Airport (DCA) in light drizzle.
Flight
Approximately 35 nautical miles from DCA, radar service was terminated. The pilot attempted to contact air traffic control but was unsuccessful. Near the Brook VOR, the pilot reported that the VOR needle moved sluggishly and the ammeter indicated a strong discharge. He also noted that the directional gyro (DG) was not functioning. Due to a decrease in ceiling, the pilot descended to 1,000 feet MSL to remain in visual flight rules (VFR) conditions. After two to three minutes, he executed a 180-degree turn to stay VFR and observed that the ceiling had lowered around him; he was in an open area approximately one to two miles wide. During the turn, the artificial horizon tumbled.
Landing
The pilot elected to make a precautionary landing on a road. During the landing, the left wing contacted a stop sign, resulting in substantial damage to the aircraft.
Post-Accident Inspection
A post-accident inspection of the aircraft did not reveal any failure or malfunction of the electrical or vacuum systems, other than the battery being nearly drained.