Flight History
Approximately three months before the accident, the pilot received about nine hours of flight instruction in the airplane, including completion of an instrument proficiency check. The accident flight was a personal cross-country flight conducted under instrument flight rules (IFR). Radar track data showed the flight proceeding west-southwest at 15,800 feet mean sea level (msl) as it approached the destination airport. The air traffic controller cleared the flight for a GPS approach. After passing the initial approach fix, the airplane began a descent as permitted by the procedure. Track data indicated that the flight became established on the initial approach segment and remained above the designated minimum altitude of 12,000 feet msl. Average descent rates ranged from 500 feet per minute (fpm) to 1,000 fpm during this portion.
At the intermediate navigation fix, the approach procedure required a right turn to a north-northwest course toward the airport. The track data showed that the flight entered a right turn about one mile before reaching the intermediate fix. As the airplane turned, its average descent rate reached 4,000 fpm. The flight then tracked northbound for nearly 1.5 miles, initially descending at an average rate of 3,500 fpm before climbing at 1,800 fpm. Subsequently, the airplane entered a second right turn. The final three radar data points were each located within 505 feet laterally of each other and near the approximate accident site. The average descent rate between the final two data points—altitudes of 10,100 feet msl and 8,700 feet msl—was 7,000 fpm. About the time the final data point was recorded, the pilot informed the air traffic controller that the airplane was in a spin and that he was attempting to recover. No further communications were received. The airplane impacted the surface of a reservoir at an elevation of about 6,780 feet and came to rest in 60 feet of water.
Meteorological Conditions
Available meteorological data suggested that the airplane encountered clouds with tops at or above 16,000 feet msl and bases about 10,000 feet msl. The flight was likely operating in IFR conditions during the final 15 minutes. However, no determination could be made regarding whether the clouds were solid or layered. The data also suggested the possibility of both light icing and light turbulence between 12,000 and 16,000 feet msl along the flight path.
Aircraft Examination
A detailed postaccident examination of the airframe, engine, and propeller assembly revealed no anomalies consistent with a preimpact failure or malfunction.
Pilot Actions
The pilot appeared to be managing the flight appropriately during the initial descent. However, it could not be determined why he was unable to navigate to the approach fixes and maintain control of the airplane as he turned toward the airport and continued the descent.
Probable Cause
The official probable cause is the pilot's loss of airplane control during an instrument approach procedure, which resulted in the airplane exceeding its critical angle of attack and entering an inadvertent aerodynamic stall and spin.