NTSB Factual Report

On May 27, 2018, about 1600 Pacific daylight time, a Marvin E. Morrison experimental amateur-built RV-6A airplane, N4269Y, was destroyed following a loss of control and impact with terrain shortly after takeoff from Petaluma Municipal Airport (O69), Petaluma, California. The commercial pilot and passenger were fatally injured. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight. The flight was originating at the time, and was destined for Lincoln Regional/Karl Harder Field (LHM), Lincoln, California.

According to a witness who observed the accident, shortly after taking off, and at an altitude of about 800 ft above ground level, the airplane's engine backfired and a drop in the engine rpm was heard; this was followed by smaller backfire sounds from the engine. The witness stated that it appeared that the pilot then made a turn to return to the airport. As the turn continued, the airplane's right wing entered a full stall, which was followed by the airplane entering a spin and impacting terrain.

The airplane was recovered to a secured facility for further examination.