Maricopa, AZ, USA
N6402X
Zenair CH601
The pilot departed from his home airport for a night flight to an airport he had flown to in the past. The flight was in trail with another airplane as they approached the airport from the north. Flight track data indicated that the accident airplane overflew the airport midfield about 300 ft below the traffic pattern altitude. The flight progressed well beyond the airport environment and descended to about 600 ft below the traffic pattern altitude. As the airplane began what appeared to be an extended base turn to the southeast, about 2 miles from the runway threshold, it struck an isolated and unlit hill just below its summit. Examination of the wreckage did not reveal any mechanical anomalies with the airplane or engine, and damage signatures to the propeller indicated that the engine was producing power at impact. Based on autopsy findings, the pilot had mild-to-moderate atherosclerosis in his coronary arteries. While the atherosclerosis placed the pilot at some increased risk for an acute cardiac event, there was no evidence to suggest such an event occurred and, given the pilot was communicating with air traffic control and the other airplane right up until the accident, the pilot’s cardiovascular disease was not a factor. Given the operational issued of the accident, the ethanol concentrations identified in liver tissue were from sources other than ingestion. At the time of the accident, the sun had set, but there was still light on the horizon, toward the direction the airplane was heading prior to turning toward the airport. The light conditions would have provided a challenging perceptual environment for the pilot as he looked toward the unlit terrain and peak. It was likely that the pilot’s visual attention was directed toward the airport at that time, while he monitored the other airplane and positioned himself for landing. Both factors would have impeded the pilot’s visual identification of the terrain. Further, the limited cultural lighting in the vicinity of the airport would provide few cues from which the pilot could reliably estimate distance while maneuvering. The reason for the pilot’s nonstandard flight track and flight below pattern altitude is unknown, but it is indicative of the pilot losing situational awareness as he followed the other airplane in the traffic pattern and prepared for landing over unlit and unpopulated terrain.
HISTORY OF FLIGHTOn June 9, 2020, about 2023 mountain standard time, an experimental amateur-built Zenith 601HDS, N6402X, was destroyed when it was involved in an accident near Ak-Chin Regional Airport (A39), Maricopa, Arizona. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot was based out of Phoenix Deer Valley Airport (DVT). According to his wife, he often flew at night because he enjoyed observing and photographing the night sky, and A39 was typically where he refueled the airplane. Automatic dependent surveillance-broadcast data revealed that the airplane departed DVT about 1958 and flew directly south-southeast toward the Class B airspace of Phoenix Sky Harbor International Airport (PHX). The pilot then requested a transition through the airspace, and was given clearance by air traffic controllers to enter and maintain an altitude of 4,500 ft. By 2013, the airplane had cleared the airspace to the south and continued a direct track toward A39. At 2021 (figure 1), it reached A39 and proceeded to fly directly over the airport at an altitude of 2,000 ft msl (700 ft agl). Over the next 2 minutes, the airplane began a sweeping 1.25-mile radius left turn during which time it climbed to about 2,175 ft and descended to 1,700 ft. The last recorded target indicated that the airplane was at an altitude of 1,700 ft, about 250 ft south of the 1,735 ft peak of an isolated hill, about 2 miles east of the approach end of runway 22. A pilot flying a Piper PA28 airplane was also inbound to A39 about the same time as N6402X. He reported that he was just ahead of the airplane as they both transitioned through the Class B airspace, and that he could see the airplane on his ADS-B receiver and heard the pilot talking to air traffic controllers. He stated that both he and the pilot of N6402X communicated their positions to each other throughout the approach. The PA28 pilot stated that he overflew the airport above the pattern altitude, with the intention of joining the left traffic pattern for runway 22. As he joined the downwind leg, he could see N6402X fly over the runway in trail but appeared to be well below the pattern altitude (figure 1, 2). He was concerned that he needed to give N6402X space to land, so he cut the downwind leg short, and as he turned onto final, he heard the other pilot reporting he was on the base leg. He could see the lights of N6402X in the distance and was still concerned that it was too low. Figure 1 – N6402X and PA28 flight track Figure 2 – N6402X and PA28 flight track After landing, the pilot of the PA28 taxied to the fuel island in anticipation of watching N6402X land. He could not see or hear an airplane in the pattern, so he became concerned and called Flight Service to report the airplane as missing. He described the conditions during the landing approach as very dark, with just a faint hint of blue on the horizon by the time he landed. He stated that the desert area surrounding the airport to the east was unpopulated, generally unlit, and ground features and terrain were not visible. The wreckage was located on the southeast face of the 1,735 ft hill, about 10 ft below the peak (figure 3). Video footage, recorded from a security camera 0.75 miles south of the accident site, revealed that the airplane flew directly over the camera location and toward the hill. As the airplane approached the peak, its landing lights briefly illuminated the terrain, just before the airplane impacted. The airplane did not appear to be trailing smoke or vapors prior to impact. Figure 3 – Wreckage on the hill face with the airport in the background The pilot’s wife stated that he carried a SPOT tracking device in the airplane, so she could monitor his location. On the night of the accident, he had not returned home by midnight (which was not unusual when he was flying), so she checked the SPOT device, which indicated that his last location was about 2 miles east of A39, at 2022. PERSONNEL INFORMATIONReview of the pilots last four flights indicated that they were all flown at night, which included a flight from DVT to A39 and a return flight from A39 to DVT. AIRCRAFT INFORMATIONExamination of the wreckage and maintenance logbooks did not reveal the existence of any terrain awareness flight instruments, and impact damage and postaccident fire prevented an accurate assessment of the operational status of the altimeter. METEOROLOGICAL INFORMATIONSunset and the end of civil twilight occurred at 1935 and 2005 respectively. At the time of the accident, the moon azimuth was 224°, at an altitude of 20°, and 84% of its visible disk was illuminated. AIRPORT INFORMATIONExamination of the wreckage and maintenance logbooks did not reveal the existence of any terrain awareness flight instruments, and impact damage and postaccident fire prevented an accurate assessment of the operational status of the altimeter. WRECKAGE AND IMPACT INFORMATIONThe accident site was located near the peak of a 1,735 tall hill. The hill was on the western edge of the of a sparsely populated and unlit area, about 20 miles south of the Phoenix suburbs (figure 4). Figure 4 – Remote area east of the airport The airplane came to rest on a north-northwest heading on the hill face. The entire cabin had fragmented and was consumed by fire, along with most of the cabin contents and all the flight instruments. The leading edges of both wings sustained 45° crush damage to their undersides through to the main spar. Both wings remained attached through the spar carry through, and the empennage remained largely undamaged. Examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation. The propeller spinner exhibited compression and scoring damage, opposite the direction of rotation. The composite propellor blades had been consumed by fire, but their internal steel tortional rods were intact and sustained bending damage opposite the direction of rotation. MEDICAL AND PATHOLOGICAL INFORMATIONThe pilot held a third-class medical certificate with the limitation that he must wear corrective lenses for near and distant vision. His most recent FAA medical certification exam was on May 4, 2020, and at that time he reported taking no medications and having no medical conditions. No significant medical concerns or issues were identified. According to the Pinal County Arizona Medical Examiner’s Office autopsy report, the cause of death was massive blunt force trauma and thermal injury, and the manner of death was accident. While the examination was limited by the extensive injuries, other than mild to moderate coronary artery disease (50% stenosis in the left anterior descending coronary artery and 60% to 70% stenosis in the left main coronary artery), no significant natural disease was identified by the medical examiner. Toxicology testing performed by the FAA Forensic Sciences Laboratory and Pinal County Arizona Medical Examiner’s Office did not identify the presence of any screened drug substances or ingested alcohol.
The pilot’s loss of situational awareness and descent below pattern altitude during the landing approach, which resulted in collision with terrain at night.
Source: NTSB Aviation Accident Database
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