What happened
On the evening of December 20, 2013, a Robinson R44 helicopter, registration F-GPJG, departed from a private helisurface in Lugon-et-l’Île-du-Carney for a recreational flight. The pilot was accompanied by three passengers, including a property buyer. Following a departure heading east, the aircraft entered a wide right-hand turn west of Libourne, eventually following the course of the Dordogne River.
Radar tracking was lost as the aircraft traveled west along the river. Witnesses on the ground observed the helicopter flying at a very low altitude, approximately 10 to 15 meters above the water, after appearing to descend steeply. The aircraft subsequently struck the surface of the river and was discovered at the bottom of the water that night, roughly 2,000 meters from the last radar contact.
The investigation
The investigation focused on the wreckage and the circumstances surrounding the flight. Examination of the Robinson R44 airframe and engine revealed no mechanical failures prior to the impact. The wreckage showed that the tail boom ruptured near the tail rotor upon the initial contact with the water. The impact occurred with a high horizontal speed but low vertical speed, causing the aircraft to pitch forward and sustain heavy structural damage. The engine was still operational at the time of the crash.
Investigators noted that the "governor off" warning light was illuminated upon impact. While witnesses reported the pilot had consumed wine during a preceding meal, they noted he appeared fit to fly. The investigation also ruled out fuel exhaustion, as the aircraft had been in flight for only about ten minutes and the low-fuel warning light was extinguished.
Findings
- The primary cause of the accident was the decision to conduct and continue a flight at extremely low altitude over the water.
- Difficulty in accurately judging height above a large body of water.
- Visual impairment caused by the low position of the sun on the horizon relative to the pilot.
- The celebratory atmosphere of the day, which may have encouraged the pilot to perform improvised maneuvers.