On July 12, 2010, at 1500 Alaska daylight time, a Cessna 172N, N6594D, collided with terrain 34 miles southeast of Palmer, Alaska, while attempting to fly over the Knik Glacier. The airplane was operated by the Elmendorf Air Club under the provisions of Title 14 Code of Federal Regulations, Part 91, and rented to the private pilot. The pilot and his two passengers were not injured, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and a visual flight plan had been filed. The flight originated at Elmendorf Air Force Base, Alaska, at 1410.

The pilot reported to the Safety Board investigator that he had flown up and over the Knik Glacier before, but he had been solo at the time, and this was his first time with pasengers. He approached the glacier at 1,500 feet mean sea level (msl) and maneuvered the airplane in to a climb. He noticed that the airplane's performance was degraded compared to his previous crossings, and he attributed it to the extra weight of his two passengers, however, he believed he would still make it over the glacier. At the 8,000 foot msl level he noticed that he was much closer to the glacier than he expected and decided to turn back. He started a right hand turn, but the airplane was too low and slow; the airplane began to stall. The right wing tip hit the snow, then the left wing tip, then the airplane nosed in and over. They egressed from the inverted airplane, and were rescued about one hour later.

The pilot stated that the airplane and engine had no mechanical failures or malfunctions during the flight.