Aerovodochody L-29 DELFIN N129MM accident near Reno, Nevada

Probable cause

The pilot’s in-flight incapacitation due to G-induced loss of consciousness, which resulted in a subsequent impact with terrain.

NTSB analysis

The pilot of the accident airplane was participating in a closed-course air race and was varying between first and second place. During the 3rd lap of 6, the accident airplane began a climb as it neared outer pylon No. 4, where it appeared to tighten its left turn toward the inner portion of the racecourse. At the peak of the climb, the airplane entered an approximate 90° right bank and started a descent before it rolled left to an approximate 90° left bank. The airplane continued to descend in a steep left bank and nose-low attitude until it impacted terrain just beyond outer pylon No. 5.

Postaccident examination of the airplane revealed no evidence of any preexisting mechanical malfunction that would have precluded normal operation.

As the airplane rolled 90° right and pitched up, followed by a 180° left roll and descent, the pilot’s lack of control inputs following the roll indicated that the pilot likely experienced an onset of higher G loads during the left roll, which ultimately led to G-induced loss of consciousness (G-LOC). The reason for the pilot’s initial roll to the right is unknown; however, it’s likely that the pilot’s aggressive roll to the left was an effort to maintain his position in the race. It is possible that the pilot’s coronary artery disease and/or amlodipine use may have reduced his G-tolerance; however, the investigation was unable to determine if the pilot’s medical conditions or medication use contributed to the accident.

Text from the NTSB. Open the NTSB docket for WPR22FA350 for the full record.