What happened
On October 11, 2009, a Reims Aviation F177 RG, registration F-BVIM, was conducting a cross-country flight from Carpentras to Lessay. The flight began in the afternoon, but as the aircraft approached its destination, weather conditions significantly deteriorated. The pilot encountered low clouds, mist, and light rain, which forced the aircraft to descend to altitudes as low as 400 feet to maintain visual contact with the ground.
As night fell, the pilot contacted Brest Control, stating that the crew had been "taken by the night and the mist" and were unable to land at Lessay. The pilot requested radar assistance to find an alternative airfield. While following instructions to turn east toward Caen, the aircraft descended through 600 feet and struck a 400,00 and 50-meter-high electrical pylon. The impact destroyed the aircraft and resulted in two fatalities.
The investigation
The BEA investigation focused on the flight sequence, the meteorological conditions, and the pilot's decision-making process. Investigators examined the aircraft's wreckage, which showed no signs of mechanical failure prior to the collision. The investigation also reviewed the pilot's flight planning, noting that while the pilot had access to meteorological information, the impact of the strong headwind on the flight duration was not sufficiently accounted for. Radio transcripts between the crew and Brest Control were analyzed, revealing that the pilot was attempting to navigate through low-visibility conditions at very low altitudes.
Findings
- The primary cause of the collision was the loss of external visual references or the pilot's attempt to maintain them by flying at an extremely low altitude during night operations in poor weather.
- The pilot's decision to continue toward the original destination was influenced by a desire to reach the home base and an insufficient assessment of how the strong headwinds would affect the arrival time.
- Contributing factors included the onset of darkness, deteriorating visibility due to mist and rain, and potential fatigue from the long-duration flight.