Aircraft: Air Tractor AT-802A. Injuries: 1 Fatal. Location: Miles City, Mont. Aircraft damage: Destroyed.
What reportedly happened: The airplane was configured for VFR flight only. The purpose of the flight was to reposition the airplane to its base of operation about 316 miles northwest of the departure airport.
Weather conditions at the departure airport were VFR, however, the weather along the route and at the destination airport reported deteriorating weather conditions and low ceilings.
There was no record of the pilot obtaining a weather brief for the flight, however, while filing a VFR flight plan, the pilot informed the weather briefer that he already had weather information, and declined any additional weather information offered by the briefer.
The pilot held a commercial pilot certificate with an airplane single-engine land, airplane multi-engine land, and instrument airplane ratings. In addition, he held a flight instructor certificate with airplane single-engine land and instrument airplane ratings. He had 73 hours in simulated instrument and 7.7 hours in actual instrument flight conditions.
A witness located near the accident site heard the sound of an airplane flying low and fast from the east to the west past her home. Shortly after hearing the airplane, she heard an impact sound and immediately looked outside for the airplane. The witness stated that she did not see the airplane or any smoke in the area, however, she observed a cloud layer covering the top of the mountain ridge where the accident site was later located.
The GPS track for the flight indicated that during the later portion of the flight, the airplane descended from an altitude of about 5,869 feet MSL to 3,054 feet MSL, while conducting several course changes from the northwest to the southwest, most likely as a result of the pilot attempting to avoid or remain clear of the deteriorating weather conditions.
The GPS data further showed a climb to an altitude of about 3,241 feet MSL before turning left to a westerly heading. About two minutes later, the data showed a left turn to the southwest at an altitude of about 3,406 feet MSL, where a descent was initiated. The last recorded data point was recorded at an altitude of about 3,284 feet MSL. The accident site was located about 0.15 miles southwest of the last recorded GPS position at an elevation of about 3,077 feet MSL.
A weather report in the area of the accident showed a visibility of two miles, mist, overcast cloud layer at 700 feet, and a variable ceiling from 400 feet to 1,100 feet.
Probable cause: The pilot’s continued visual flight rules flight into deteriorating weather conditions in an airplane not equipped for instrument flight, which resulted in a collision with terrain.
NTSB Identification: WPR11FA221
This May 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.