Flight Details
The pilot, an instrument-rated private pilot with 229 hours of flight time, departed from Bakersfield for a flight home to San Carlos Airport. The flight was conducted under bright nighttime visual flight rules (VFR) conditions. En route, the pilot contacted NAS Moffett and received permission to transit its airspace. He was instructed to report over the airport.
Encounter with Clouds
As the pilot approached the San Carlos area, he likely encountered a forecast overcast cloud layer with bases at 1,000 feet. In response, he made a 60 to 70 degree change of course away from NAS Moffett. The pilot probably attempted to continue flying beneath the clouds while passing over the densely populated and illuminated city areas.
Loss of Visual Reference
The pilot entered the base of the clouds and continued flying until reaching a mountainous region. There, he lost visual reference to the city lights. Seconds before impact, the pilot requested the frequency for a nearby radar facility.
Background
The pilot was familiar with the area, having recently learned to fly in the vicinity.