Aero Vodochody L39C N139GS accident near Davenport, Iowa

Probable cause

The loss of airplane control for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded operation.

NTSB analysis

The accident airplane was part of a 3 airplane airshow demonstration performance. After overflying the spectators and flying away from the flightline, the airplanes were executing a crossover break maneuver, which the accident airplane was in the left wing position. During the crossover break maneuver, the lead airplane first entered a climbing maneuver, the left wing position airplane entered a right turn, and then the right wing position airplane entered a left turn with adequate longitudinal spacing. During the maneuver, the accident airplane entered the right turn, descended, and impacted the terrain. A post-impact fire ensued. No evidence of any in-flight collision with the other airplanes was observed. Witnesses reported that they did not observe any movement of the airplane's flight control surfaces prior to the airplane impacting terrain, which would be inconsistent with the pilot attempting to recover from the descent. No preaccident mechanical malfunctions or failures were noted with the airplane that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for CEN12LA602 for the full record.