He has been identified as Eddie Andreini, 77, of Half Moon Bay. An Air Force spokesman says Andreini was performing an upside down acrobatic aerial maneuver when he crashed at 2:05 p.m.
Witnesses say his vintage Stearman biplane erupted in flames as it hit the ground. Black smoke rose from the wreckage as crowds were evacuated from the base.
Air show organizers canceled the event following the tragedy. No spectators were injured.
The National Transportation Safety Board and Federal Aviation Administration were leading the investigation.
Anyone with video or photos of the accident was urged to call officials at (707) 424-2000.
The Associated Press contributed to this report.