CEN20LA399

The pilot departed under visual flight rules (VFR) from a rural airport during dark night, VFR conditions. After climbing toward the destination for about 2 minutes, the pilot turned back to the airport and flew a visual approach. The airplane’s flight track was consistent with a go-around near the runway threshold, likely due to excessive airspeed, followed by a climb toward the downwind leg of the traffic pattern for the opposite runway. On an approximate left base leg, the airplane decelerated to stall speed and entered a right spin that continued until ground impact. The disposition of the wreckage was consistent with a low forward speed indicative of a stalled condition. Two weeks before the accident, the airplane’s attitude heading reference system (AHRS) failed during a daytime flight. The pilot landed uneventfully by referencing the airplane’s backup (unlit) flight instruments located on the instrument panel’s far right side. After troubleshooting the AHRS failure, the pilot made repairs to a circuit card that involved intricate soldering of a capacitor and two diodes. The accident occurred on the second flight after this repair. Examination revealed no engine or flight control anomalies. Fire damage precluded assessment of avionics anomalies. His disease placed him at increased risk of a sudden impairing or incapacitating cardiac event. It is possible that the pilot was experiencing symptoms of a heart-related medical event and that may have been the reason for his attempt to return to the airport. Furthermore, symptoms of such an event might have impaired his performance while maneuvering. However, there is no specific evidence that a such an event occurred and a systems failure involving the AHRS repair provides a reasonable alternate explanation for the pilot’s attempted return. In such a scenario, challenges related to the failure and the dark conditions might explain his loss of control, even without impairment. Thus, whether the pilot’s severe coronary artery disease contributed to the accident could not be determined. The pilot had not flown the accident airplane at night and his most recent night landing was about 5 years before the accident. The pilot’s lack of recent night experience likely contributed to his poor airspeed control during the two attempted approaches and the subsequent loss of aircraft control.

The last recorded information showed the airplane slowing to 50 knots while in a left turn. The wings-level stall speed for a Vans RV9 is reported as between 42 and 43 kts. With a bank angle of 45° the airplane’s stall speed increased to about 50 knots. The pilot recorded remarks in his logbook that, during a daytime flight 12 days before the accident in the accident airplane, he experienced an attitude heading reference system (AHRS) failure along with “burning insulation smell.” He shut down electrical equipment, including the electronic flight information system (EFIS), and landed the airplane using the analog flight instruments without incident. The analog instruments (attitude indicator, directional gyro, airspeed indicator, and altimeter) were located on the far right side of the instrument panel and were not lighted. After the AHRS failure, the pilot identified a circuit card with a capacitor and two diodes that needed to be replaced. (See Figure 2.) The pilot was a career electrical engineer and elected to remove and solder the replacement capacitor and diodes onto the circuit card himself rather than purchase a new card. The pilot completed the replacement of these components onto the circuit card and flew the airplane uneventfully the day before the accident. He noted that the AHRS and EFIS appeared to be functional. Figure 2. Photo of avionics circuit card (two failed diodes circled in red) On September 19, 2020, about 0638 eastern daylight time, an experimental, amateur-built RV9A, N94KJ, was destroyed when it was involved in an accident near Zeeland, Michigan. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The airport’s common traffic advisory frequency (CTAF) was recorded, and captured transmissions from the accident pilot that included taxi to and departure from runway 20. Shortly thereafter, the pilot reported that the airplane was on final approach for runway 02. No further transmissions from the pilot were recorded. Automatic Dependent Surveillance – Broadcast (ADS-B) information captured the airplane depart about 0633. After climbing on a southeasterly heading, the airplane turned back toward the airport. The airplane crossed the runway threshold at 95 knots and 200 ft above ground level (agl), then climbed and turned right toward the northeast. The last recorded information showed the airplane turning left on an approximate left base for runway 20 at 50 knots and 400 ft agl. (See Figure 1.) Surveillance video showed that the airplane pitched up and begin spinning to the right until ground impact; a post-impact fire ensued. Figure 1. Flight Track of Airplane The autopsy report stated that the pilot’s cause of death was atherosclerotic cardiovascular disease, and that his manner of death was natural. Autopsy of his heart identified near-complete blockage of the left anterior descending coronary artery, 50% narrowing of the leftcircumflex coronary artery, and an old area of heart muscle scarring from reduced blood supply. No tested-for substances were noted on toxicology testing, except caffeine, which generally is not considered impairing. At the NTSB’s request, an Armed Forces Medical Examiner System (AFMES) forensic pathologist reviewed evidence including the pilot’s autopsy report, toxicology information, microscope slides from the pilot’s autopsy, narrative information about the accident provided by the NTSB, and the passenger’s autopsy report. The AFMES forensic pathologist’s opinion was that the pilot’s cause of death was multiple injuries, that his manner of death was accident, and that the contribution of his atherosclerotic cardiovascular disease (severe coronary artery disease) to the accident could not be definitively determined. On the morning of the accident, sunrise occurred at 0727 and the moon did not rise until 1000. A review of pilot logs revealed about 15 flight hours of flight experience at night. The pilot’s most recent night landing occurred on October 18, 2015, and he had not flown the accident airplane at night. The airplane impacted a farm field about 1,100 ft northeast of the runway 20 threshold and a post impact fire ensued. Examination of the airplane revealed no anomalies with the engine or flight controls that would have precluded normal operation. Fire damage did not allow for assessment of avionics anomalies.