Flight History
The pilot, who held an instrument rating, obtained weather briefings for the destination airport, which reported instrument meteorological conditions including fog, mist, low visibility, and low ceilings. Departing and flying to the destination, the pilot was cleared for an Instrument Landing System (ILS) approach. The airplane tracked the localizer course, but approximately half a mile from the approach end of the runway, it initiated a climb and turned left toward the east. The airplane continued turning left and began flying north, then executed a series of left and right ascending and descending turns at various altitudes.
During the final three minutes of flight, the airplane performed 18 ascents and descents, with vertical speeds ranging from plus 4,600 feet per minute to minus 6,000 feet per minute. Altitude fluctuated between 600 and 1,800 feet above mean sea level.
Witness Observations
Two witnesses reported hearing the airplane fly loudly overhead before it collided with terrain. They noted that the weather was very foggy at the time.
Weather Conditions
At the time of the accident, the weather reported at the destination airport included zero visibility, fog, and vertical visibility of 100 feet.
Pilot Information
The pilot was instrument rated. The FAA Flight Training Handbook Advisory Circular (AC) 61-21A states: "If neither horizon or surface references exist, the airplane's attitude must be determined by artificial means - an attitude indicator or other flight instruments. Sight, supported by other senses such as the inner ear and muscle sense, is used to maintain spatial orientation. However, during periods of low visibility, the supporting senses sometimes conflict with what is seen. When this happens, a pilot is particularly vulnerable to spatial disorientation."
Toxicology
Two independent toxicology reports detected chlorpheniramine, a sedating antihistamine, in the pilot's blood and urine.