What happened
On the evening of August 24, 2001, a pilot initiated a night flight for local circuit training at the Mimizan airfield. After performing standard pre-flight checks and engine tests, the pilot departed on runway 26 in a Cessna 172 N, registration F-GCHV. Shortly after takeoff, the pilot transmitted a radio message requesting increased runway lighting intensity, indicating a developing difficulty with visibility. Shortly thereafter, the aircraft struck trees in a dense pine forest approximately 2,200 meters south of the airfield. The impact occurred at a high speed and a steep nose-down attitude, resulting in the destruction of the aircraft and the death of the pilot.
The investigation
The investigation examined the wreckage, meteorological data, and technical components of the aircraft. Investigators found that the aircraft's vacuum pump and pneumatic circuit were in good working order. While some damage was noted on the artificial horizon, it was determined to be unrelated to the accident's cause.
Meteorological analysis revealed that while the sky was clear at the time of departure, maritime fog and low stratus clouds were moving inland. Although the pilot had access to various weather documents, the investigation noted that the specific risks associated with the Mimizan airfield—which is prone to rapid sea fog incursions—were not sufficiently accounted for. Additionally, it was discovered that the pilot was wearing replacement corrective lenses that were not his usual pair and caused significant reading difficulties, which may have hindered his ability to maintain visual references.
Findings
- The primary cause was an erroneous assessment of the evolving night VFR meteorological conditions and an insufficient consideration of the specific weather risks at the coastal Mimizan airfield.
- A rapid degradation in weather led to the loss of external visual references and subsequent loss of aircraft control.
- The use of inadequate corrective eyewear acted as a contributing factor to the loss of visibility.