(Pilot) And The Right Seat Passenger/Observer Detected Smoke In The Cockpit/Cabin Area

On July 20, 2020, about 0938 Pacific daylight time, a McDonnell Douglas 600N helicopter, N745BW, was destroyed when it was involved in an accident near San Andreas, California. The pilot and two passenger/observers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. In a telephone interview with the National Transportation Safety Board investigator-in-charge, the pilot reported that while performing low-altitude inflight powerline visual assessment operations about 250 ft above ground level (agl), and while on the second circuit of the morning, he and the right seat passenger/observer detected smok