What happened
On February 19, 2002, a Cessna 421 B (registration F-GHUY) departed from Libourne airport bound for Toussus-le-Noble. The flight was conducted under VFR/IFR flight plan "Z" conditions. Shortly after takeoff from runway 22, the aircraft performed an initial right-hand turn before entering a very tight left-hand turn with a high bank angle. Within thirty seconds of departure, the aircraft struck trees and crashed into a field near Artigues-de-Lussac, where it was destroyed by a post-impact fire. The accident resulted in three fatalities: two pilots and one passenger.
The investigation
The investigation focused on the wreckage, engine performance, and radar data. Investigators examined the airframe, noting that the landing gear had been retracted and the aircraft had struck trees at an angle of approximately 45 degrees. While the fire destroyed much of the instrumentation and flight control continuity, the engines (GTSIO 520H) were examined at a specialized center.
Engine analysis revealed that the left turbocharger showed signs of rotation at impact, whereas the right turbocharger did not. This suggested a power asymmetry between the two engines at the moment of impact. Radar plots from the CRNA Sud-Ouest confirmed the aircraft's rapid change in direction, moving from a right turn to a sharp left turn. Witnesses at the airfield observed a normal takeoff and the retraction of the landing gear, but noted an explosion and smoke appearing a few kilometers away less than thirty seconds later. One witness near the crash site also observed that one of the propellers appeared not to be rotating.
Findings
- The aircraft experienced a loss of control during the initial climb phase.
- There was evidence of power asymmetry between the two engines at the time of impact.
- The investigation could not definitively determine the specific cause of the power imbalance or its exact contribution to the loss of control.
- The aircraft remained in visual flight conditions throughout the short duration of the flight.