Background and Departure
The instrument-rated private pilot obtained a weather briefing and filed an instrument flight plan for a personal flight to attend a stock car race. On the morning of the accident, the pilot contacted ATC for an instrument clearance. The pilot was given a clearance with a 10-minute void time and departed two minutes before its expiration.
Non-Volatile Memory Data Analysis
Recorded non-volatile memory data from the electronic cockpit flight display system were downloaded and analyzed. The data revealed that, while climbing in instrument conditions, the pilot attempted to increase the aircraft's climb rate using the vertical speed bug on the glass Primary Flight Display. However, the PFD had failed to align and was not fully functional. As a result, bug settings (altitude and vertical speed) were suppressed and not transmitted to the autopilot computer. The autopilot did not command an increased climb rate. The rate of climb momentarily increased twice, likely due to pilot control inputs via the control wheel. A review of the PFD Pilot's Guide indicated it does not inform pilots about suppression of bug settings when the PFD is unaligned.
Flight Path and Autopilot Issues
Soon after the last vertical speed bug change, the aircraft's vertical speed began to fluctuate significantly, oscillating between climbing and descending for about nine minutes. During this period, the airplane completed three left-hand orbits at varying altitudes. The pilot reported an "autopilot problem" to ATC and requested a clearance to divert to a nearby airport. The course deviated left again, and the pilot again reported a problem with the autopilot. The airplane continued flying for another 4 minutes as vertical speed oscillated. The ground track remained erratic and was not consistent with a course toward the diversion airport. The airplane entered an uncontrolled descent, impacted terrain, and was destroyed.
Wreckage Examination
Examination of the wreckage revealed the pitch trim jackscrew was in the full nose-down position. No preimpact malfunctions of the autopilot or flight control systems were discovered. The nose-down trim condition likely resulted from the pilot pulling on the control wheel with the autopilot engaged, which would have caused the trim to run nose down. Exams of other systems, structure, and engine found no evidence of preimpact malfunctions or failures.
Spatial Disorientation and Pilot Experience
Risk factors for spatial disorientation were present, including IMC and maneuvering flight. Analysis of the flight path and pilot communications indicated that the pilot became spatially disoriented while attempting to maneuver with reference to a degraded PFD. The pilot was instrument current and qualified, with about 291 hours operating the electronic flight display system. He had received formal training in two models of airplanes equipped with the same system and had experienced a failure of the display system on a previous airplane, suggesting familiarity with PFD functionality.
PFD Alignment Issues
NVM data revealed the PFD had not aligned during its power cycle for the accident flight, nor on the previous power cycle that occurred the same day. The previous power cycle lasted 333 seconds, during which the airplane was taxiing—movement during the initial alignment phase hinders system alignment. The PFD screen displays a message: "INITIAL AHRS ALIGNMENT / REMAIN STATIONARY / OK TO TAXI in xx SECONDS." After the 333-second cycle, the system was shut down and restarted for the accident flight. No movement was recorded during the critical alignment period of this cycle, although the airplane did taxi during the "OK TO TAXI" period. The investigation could not conclusively determine why the PFD would not align, but the airplane departed 375 seconds after PFD power-up, which may not have been sufficient time for alignment. Typical stationary alignment time is 166 seconds. Time to align when taxiing during "OK TO TAXI" varies considerably; a previous similar taxi event took 416 seconds to align.
Display of Red X's and Standby Instruments
According to the flight display manufacturer, failed alignment in both power cycles would have resulted in red X's displayed on the PFD. Based on recovered information, it is likely red X's were displayed at takeoff time. The airplane was equipped with traditional standby flight instruments (attitude indicator, altimeter, airspeed indicator, magnetic compass) and dual GPS, which should have provided sufficient information for safe continued flight after PFD failure.
System Reliability and Magnetometer Corrosion
The investigation revealed a history of numerous failures affecting the flight display system's reliability. Examination of the accident airplane's magnetometer showed evidence of fretting corrosion in flight-critical components, which could result in further malfunctions. However, the investigation did not confirm any other malfunction or failure of the electronic flight display system at takeoff, aside from the PFD's failure to align.