The National Transportation Safety Board has determined what caused the crash of an airplane a year ago in Clearwater County.
The plane, piloted by Andrew Lindberg of Farmington, disappeared while Lindberg was flying to a hunting destination to meet his father in Hallock on November 13, 2009. I wrote about it at the time:
There was no moon on Friday. It wouldn't have appeared over the horizon in Mahnomen until 5:13 Saturday morning. It would have been difficult to detect the horizon. There's also plenty of swamps and water in the area, and the air temperature was cooling. The temperature/dewpoint spread around that time was less than 2 degrees in Mahnomen. That means fog was likely forming, too.
These are conditions that are challenging for even the most experienced pilot. They would have more so, of course, for a pilot with very little experience. Mr. Lindberg got his pilot's certificate in September, according to reports.
The NTSB issued its investigation finding this week, saying Lindberg likely crashed because of "spatial disorientation," after he flew into weather conditions he was warned about:
The non-instrument rated pilot received an outlook weather briefing about 6 hours before the accident flight. The briefer informed the pilot that instrument flight conditions existed and were expected to continue with improvement expected the following day. There were no records of additional weather briefings before the accident flight. Weather and global positioning system data showed that the airplane flew into an area of instrument weather conditions about 210 nautical miles into the 290 nautical mile night cross-country flight. The GPS data showed that in the last minute of the flight the airplane turned left from a heading of about 340 degrees to 300 degrees, followed by a right turn to a heading of 015 degrees which corresponded to the last recorded position. The airplane's average groundspeed during the last 20 seconds of the recorded data was about 120 knots. The recorded cloud base heights at airports near the accident site were as low as 400 feet overcast east of the accident site with higher cloud bases to the west of the accident site. It is likely that the sustained turn sequences while in night instrument meteorological conditions resulted in spatial disorientation. The airplane impacted trees and terrain, and a post-impact fire ensued. No pre-impact anomalies were found with respect to the airplane or its systems.