What happened
On October 9, 2009, at approximately 05:30 UTC, a pilot departed from the Epinal Dogneville aerodrome in France, heading toward Vitry-le-François. The mission involved a positioning flight to pick up a technician for a gas pipeline surveillance task.
Twelve minutes into the flight, the AS 350 B3 helicopter, registration F-GKRL, struck an initial row of trees. The aircraft then flew over a residential building before colliding with a second row of trees. The impact caused the total destruction of the aircraft. The pilot was killed in the accident.
The investigation
The investigation examined the aircraft's technical condition, the pilot's experience, and the meteorological conditions at the time of the accident. Technical inspections of the engine, rotor blades, flight controls, and transmission systems revealed no mechanical failures or malfunctions that could explain the crash. Data from the engine control unit (DECU) and the flight parameter recorder (Brite Saver) showed no technical anomalies prior to the impact.
Meteorological analysis indicated that while the pilot had checked for fog via telephone prior to departure, the local conditions at the accident site were likely characterized by low stratus clouds or fog, which significantly reduced visibility. Nearby stations reported high humidity and low ceilings in the region during that timeframe.
Findings
- The aircraft was operating in a descending trajectory and was tilted approximately 45 degrees to the left at the moment of the first impact.
- Low visibility due to fog or low stratus clouds at the accident site likely contributed to the pilot's inability to maintain terrain clearance.
- Toxicological analysis of the pilot's blood revealed levels of pholcodine, an antitussive substance, exceeding therapeutic levels. While this medication is available without a prescription, its potential to induce drowsiness was noted.
- There was no evidence of any mechanical or technical failure of the aircraft's components.