What happened
On October 18, 2013, a Cessna 500 operated by Dufresne, Inc. crashed near Derby, Kansas, resulting in 2 fatal injuries. The aircraft, registration N610ED, departed Wichita Mid-Continent Airport (ICT) for New Braunfels Regional Airport (BAZ) under instrument flight rules.
After climbing to and leveling at 15,000 feet, the aircraft departed controlled flight. Radar data showed the airplane began a meandering course and eventually entered a descending left turn. The final radar contact occurred at 10:16:51 CDT, showing the aircraft at 10,100 feet. Witnesses reported seeing the airplane in a nose-down vertical dive trailing smoke, followed by an immediate explosion and fireball. The aircraft impacted the terrain in a near-vertical attitude, creating a large impact crater and causing a post-impact fire.
The investigation
Investigators examined the wreckage and found the airplane was extensively fragmented. While most of the wreckage was located within a single impact crater, a portion of the left wing had separated and traveled approximately 3,100 feet from the main site. Examination of the left wing revealed several previous repairs that included improperly installed rivets, unapproved materials, and excessive fuel tank sealant.
Both engines showed evidence of being in a middle to high power range at the time of impact. No evidence of pre-impact mechanical failures or engine malfunctions was found that would have prevented normal operation.
Prior to the accident, the pilot had reported several instrument malfunctions to a maintenance professional, including issues with the horizontal situation indicator (HSI) and the artificial horizon (AH) gyros. While the right-side AH gyro had been replaced, the pilot had not addressed other malfunctioning equipment, such as the autopilot or other gyroscopic instruments.
Findings
At the time of the accident, the aircraft was flying in instrument meteorological conditions (IMC) and had entered an area containing supercooled large water droplets and severe icing. The investigation determined that the accumulation of structural ice, combined with the pilot's increased workload due to ATC instructions and the presence of malfunctioning flight instruments, likely led to spatial disorientation and the subsequent loss of control.