What happened
On January 16, 2013, a Pilatus PC-12/45, registration N68PK, crashed approximately 5 miles northeast of Burlington-Alamance Regional Airport (BUY) in North Carolina. The flight, operated by LabCorp, Inc., was performing a medical specimen transport under instrument flight rules (IFR) toward Morristown, New Jersey.
At approximately 0550, the pilot received an IFR clearance including an initial altitude of 3,000 feet and a specific transponder code. During the climb, the pilot contacted air traffic control to report climbing through 3,000 feet, but was informed that the transponder code he had entered was incorrect and was instructed to reset it.
Shortly after this interaction, the aircraft reached a maximum altitude of approximately 3,326 feet before entering a descending right turn. Data from the enhanced ground proximity warning system (EGPWS) recorded a descent rate of 11,245 feet per minute, triggering "sink rate" and "pull up" warnings. The aircraft subsequently entered another turning descent and impacted the terrain. The pilot was fatally injured.
The investigation
Investigators examined the wreckage, which was found fragmented across an 800-foot-long debris path. The engine showed no evidence of anomalies that would have prevented normal operation, and the engine was producing power at the time of impact. Mechanical examination of the flight control systems, including the aileron, elevator, and rudder, confirmed continuity.
An examination of the KFC-325 autopilot system revealed an open resistor in the KCP-220 flight computer. This condition could cause the autopilot to appear engaged while the pitch and roll servos fail to actually engage. It could not be determined if this resistor failure occurred during the flight or due to the impact.
Findings
- The aircraft was operating in dark night instrument meteorological conditions (IMC).
- The pilot's attempt to correct the transponder code may have served as an operational distraction, contributing to a breakdown in the instrument scan.
- If the autopilot was engaged and the resistor was in an open condition, the pilot's failure to detect the resulting malfunction could have contributed to the loss of control.
- The circumstances of the accident are consistent with the effects of spatial disorientation.