WPR12LA365

The flight instructor reported that, as he and the pilot-rated passenger flew through a canyon, the airplane gained airspeed and altitude. As they continued toward their destination, the flight instructor directed the pilot to turn right at a branch in the canyon. Shortly after, the terrain elevation increased, and it exceeded the airplane's climb performance, and the airplane subsequently impacted trees. The density altitude for the area was calculated to be about 8,524 feet, which would have affected the airplane's climb performance. A postaccident examination of the engine revealed no evidence of mechanical malfunctions or failures that would have prevented normal operation.

On August 20, 2012, about 1115 mountain daylight time, a Cessna 182Q, N735KV, sustained substantial damage when it impacted trees and terrain during climb in rising mountainous terrain near McCall, Idaho. The flight instructor and his commercial pilot-rated student both received minor injuries. The owner/pilot was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the instructional cross-country flight, which had originated from Mackay Bar Airport, Dixie, Idaho, about 15 minutes before the accident. The flight instructor said the intended destination was McCall; a flight plan had not been filed. The flight instructor said they departed Mackay Bar Airport (elevation 2,172 feet) and flew down the Salmon River while gaining speed and altitude. At Warren Creek they turned south while still climbing. They came to a "Y" in the canyon and he directed the pilot receiving instruction to take the right branch. Soon thereafter the increase in terrain elevation exceeded the airplane's climb performance. The airplane impacted trees and struck the ground. The elevation of the accident site was about 6,593 feet. The nearest weather reporting station reported the temperature was 65 degrees Fahrenheit and 30.15 inches of mercury pressure, which calculated to a 8,524-foot density altitude. The engine was shipped to Continental Motors, Inc., and on March 27, 2013, it was examined in the presence of a National Transportation Safety Board investigator. No evidence of any pre-impact mechanical discrepancies was found with the engine that would have prevented normal operation.