CESSNA 310R — Palo Alto, CA

What happened

The pilot departed the airport in near-zero visibility instrument meteorological conditions, and shortly after takeoff, struck a power pole and power lines before impacting terrain. Review of recorded air traffic control tower (ATCT) transmissions revealed that the pilot was initially given his instrument flight rules (IFR) clearance to turn right to a heading of 060 degrees and climb to 3,000 feet. Shortly after verifying his IFR clearance, the pilot received his IFR release from the ATCT controller and was informed that the runway was not visible to the controller. The controller further informed the pilot that takeoff was at his own risk. Shortly after, the controller notified the pilot that he had two minutes for his IFR release, before it expired. The pilot stated that he did not hear a "cleared for takeoff" instruction from the controller. The controller responded that he could not clear the pilot for takeoff, due to not having the runway environment in sight and that "the release is all yours and it's at your own risk sir." The pilot acknowledged the transmission and proceeded to take off. One witness, who was adjacent to the accident site, reported that she observed an airplane “suddenly appear from the fog” left of her position. The witness stated that she continued to watch the airplane fly in a level or slightly nose up attitude until it impacted power lines.

Accident site evidence was indicative of a level impact with a power pole about 50 feet above ground level (agl) and at a high airspeed. All major structural components of the airplane were located within the wreckage debris path. Examination of the airframe, engines and propellers disclosed no evidence of any preimpact mechanical anomaly. Weather conditions reported five minutes prior to the accident were wind variable at 5 knots, visibility 1/8th mile, fog, and vertical visibility of 100 feet agl. Weather conditions recorded by the ATCT 11 minutes after the time of the accident were visibility 1/16th mile, fog, and a vertical visibility of 100 feet agl.

Local law enforcement provided recordings from a sound recording system, which captured the accident sequence. The recordings were coupled with airport surveillance radar to interpolate a flightpath for the airplane. The interpolated flightpath indicated an approximate 45-degree left turn shortly after departure to the area of initial impact with the power pole and power lines. A sound spectrum study determined both engines were operating near full power.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.