What happened
On August 4, 2018, a De Havilland DHC-2 operating as K2 Aviation crashed into steep, snow-covered terrain in Denali National Park and Preserve, approximately 50 miles northwest of Talkeetna, Alaska. The flight was a scheduled one-hour commercial air tour of glaciers and the Denali climber base camp.
At 1705, the aircraft, registration N323KT, departed Talkeetna Airport. At 1746, GPS tracking showed the airplane changed course near the Denali summit and proceeded southeast down the Kahiltna glacier valley. At 1753, the Alaska Rescue Coordination Center received an alert from the airplane's emergency locator transmitter. Shortly after, the pilot contacted K2 Aviation via satellite phone, stating that the aircraft had hit the side of a mountain and requesting rescue.
On August 6, a National Park Service helicopter located the wreckage in a crevasse on a hanging glacier on Thunder Mountain at an elevation of approximately 10,920 feet. The crash resulted in 5 fatal injuries, including the pilot and four passengers.
The investigation
Due to the extreme terrain, including a crevasse and avalanche hazards, the NTSB was unable to access the wreckage, and the occupants were not recovered. An on-scene assessment by a park ranger indicated the airplane had impacted in a near wings-level attitude, with the right wing separating from the fuselage.
Weather analysis showed broken cloud bases at 700 feet and overcast clouds at 1,000 feet. The freezing level was at 9,866 feet, which supported light-to-moderate rime icing. Based on the impact evidence and weather data, it is likely the pilot entered an area of reduced visibility and failed to see the terrain before the wing struck the snow.
Investigation into company operations revealed that K2 Aviation did not require pilots to report route changes to base, and the company did not use a formal, written preflight risk assessment process, relying instead on verbal conversations between pilots and flight followers.
Eight months after the accident, a National Park Service assessment found that a glacier calving event during the winter had released thousands of tons of ice and debris, and the wreckage was no longer visible at the original crash site.