The airplane collided with terrain while maneuvering at about 1250 Pacific time. The commercial pilot and second pilot were killed; the airplane was substantially damaged. Visual conditions prevailed. A witness reported observing the airplane perform aerobatics and then return to the airport, where the pilot added oil to the onboard smoke system. Shortly, the airplane departed and the pilot performed aerobatics for 10 to 15 minutes. The witness observed the airplane begin a spin at low altitude with white smoke being generated. The airplanes rotation increased as the airplane neared terrain and it subsequently crashed.
