Yakovlev YAK-55M N176FD accident near Stevens Point, Wisconsin

Probable cause

The pilot's failure to maintain airplane control during the aerobatic flight, which resulted in the airplane exceeding its critical angle of attack and entering an accelerated stall at a low altitude.

NTSB analysis

The pilot was performing an aerobatic flight at an airshow event when the accident occurred. The flight team manager witnessed the accident and reported that the airplane entered an intentional inverted flat spin at the apex of an inside loop maneuver. The airplane completed more than 3 rotations in the inverted flat spin before recovering into a dive. The team manager then saw the airplane pitch up and enter an "aggressive" left turn. A review of ground-based video footage confirmed the sequence of events reported by the team manager and showed that, after the pitch up and left roll, the airplane entered a nose-low, descending left spiral that continued to ground impact. The observed flight path was consistent with an accelerated aerodynamic stall after the pilot had recovered from the inverted spin at a low altitude. The airplane cockpit was equipped with an aft-facing video camera that captured the pilot and his flight control movements. A review of the available cockpit footage confirmed that the pilot remained conscious throughout the accident flight and that the ailerons, elevator, and engine had responded to his control inputs. Although the rudder was obstructed from view in the video by the pilot's helmeted head, his observed leg movements were consistent with expected rudder inputs throughout the flight. Further, a postaccident examination of the airplane did not reveal any mechanical anomalies that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for CEN14FA266 for the full record.