Amateur-built GLASTAR N8488 accident near Cal-Nev-Ari, Nevada

Probable cause

The pilot's failure to maintain sufficient altitude for undetermined reasons while maneuvering to land in dark night conditions, which resulted in collision with terrain.

NTSB analysis

The pilot and passenger departed for a cross-country flight in dark night conditions, with the moon below the horizon. The pilot’s friend recorded the accident flight departure, which appeared normal. They were communicating over the radio, and the pilot did not report any problems. The airplane continued toward an unpopulated, hilly area for about 11 minutes before the pilot initiated a 180° turn back to the departure airport. Security camera footage captured the airplane’s lights as it approached the runway before descending rapidly into terrain.

The airplane came to rest in desert terrain about 3,350 ft from the north end of the runway, with the wreckage path leading away from the runway. The airplane impacted the ground in a near-level pitch attitude with the flaps extended. During the landing roll, the propeller struck the ground and separated from the engine, yet the airplane retained enough airspeed to briefly become airborne, traveling about 920 ft before contacting the ground again.

The pilot’s pre-event cardiac testing revealed an abnormal nuclear stress test with evidence of reversible ischemia. This indicates the pilot likely was at increased risk of a sudden distracting, impairing, or incapacitating cardiac event, including angina, arrhythmia, or heart attack. There is no forensic evidence that such an event occurred. However, such an event could not be excluded given the limitations of the autopsy due to fragmentation. Therefore, whether the pilot's heart disease contributed to the crash could be determined.

The reason for the airplane’s return to the airport was not determined. The airplane’s flight path and ability to maintain altitude during its return to the airport is inconsistent with a loss of engine power. Examination of the airplane was limited due to the extensive fragmentation of the airframe. During the examination, the engine fuel supply line was found to have a loose b-nut; however, it is unknown if the loose b-nut affected the performance of the engine.

The pilot’s logbooks and the airplane’s GPS information indicated that the pilot likely did not have recent night flying experience. The area of the accident flight was rural, with little terrestrial lighting present. Given the dark night conditions and the airplane’s rapid descent into the ground, the pilot likely experienced visual illusion or spatial disorientation while maneuvering back to the airport for undetermined reasons.

Text from the NTSB. Open the NTSB docket for WPR23FA153 for the full record.