What happened
The pilot departed DCA under light drizzle conditions after receiving a weather briefing that forecasted IFR conditions after 1800 EST. Approximately 35 NM from DCA, radar service was terminated, and the pilot was unable to establish contact with ATC.
While near the Brook VOR, the pilot observed the VOR needle moving sluggishly and noted a strong discharge on the ammeter. The pilot also observed that the directional gyro (DG) was not functioning. Due to a decreasing ceiling, the pilot descended to 1000 FT MSL to maintain VFR conditions.
After two or three minutes, the pilot executed a 180-degree turn to remain within VFR conditions. During this maneuver, the pilot noted that the ceiling had decreased, leaving an open area only approximately one to two miles wide, and observed the artificial horizon tumbling. The pilot elected to perform a precautionary landing on a road. During the landing, the left wing of the aircraft struck a stop sign, resulting in substantial damage.
The investigation
A post-accident inspection of the aircraft was conducted. The investigation failed to reveal any mechanical failure or malfunction within the electrical or vacuum systems, though it was noted that the battery was nearly drained.