Flight Purpose and Preflight
The flight was intended to deliver the airplane for electrical system maintenance. The pilot checked the weather three times before telephoning radar approach control and requesting a special VFR (SVFR) clearance, stating that the flight would be conducted on battery power.
Clearances and Approach
After takeoff, the pilot was issued a clearance. Subsequently, an inflight advisory indicated that weather conditions were not favorable for SVFR, prompting the pilot to request an IFR clearance. The pilot was then assigned vectors for an ILS approach. During the approach, the pilot reported having instrument problems and expressed concern about losing communications capability.
Loss of Contact and Crash
After the controller initiated a no-gyro airport surveillance radar (ASR) approach, contact with the pilot was lost. The airplane subsequently crashed.
Post-Accident Examination
Disassembly of the vacuum pumps, vacuum-driven flight instruments, and electrically driven flight instruments revealed no defects. However, light bulbs in the instrument panel showed filament stretching, indicating that the instruments were operational at the time of impact.