What happened
On July 23, 2004, a student pilot was conducting a solo navigation flight in a Cessna 152, registration F-GKAX, departing from Toussus-le-Noble. The flight plan involved stops at Auxerre and Blois. Although the flight was delayed from the morning due to fog, the pilot proceeded in the early afternoon after reviewing weather reports that suggested possible showers.
While flying toward Blois, the pilot encountered a sudden, intense rain shower that significantly reduced visibility. Attempting to turn back, the pilot became disoriented. During the period of disorientation, the pilot attempted to contact Auxerre AFIS, but communication was poor due to incorrect radio settings. Subsequent attempts to contact Seine Information on alternative frequencies were unsuccessful due to a misunderable frequency instruction.
After encountering a second heavy shower and fearing a total loss of visual references, the pilot decided to terminate the flight and perform an emergency landing. After rejecting an initial field, the pilot selected a second location but ultimately landed in a cornfield. Upon touchdown, the nose gear sank into the mud and broke, causing the aircraft to nose over onto its back, resulting in heavy damage to the aircraft.
The investigation
The investigation focused on the pilot's preparation and the meteorological information available at the time of departure. Investigators examined the use of the "Olivia" weather information system, which the pilot used to review TAF and METAR reports. It was noted that the system's default settings provided weather for a specific corridor, and because Blois was listed as a destination/diversion, the system did not display information for airports outside that specific range.
Furthermore, the investigation reviewed the TEMSI weather chart valid at the time, which indicated the presence of convective activity and thunderstorms associated with cumulonimbus clouds. The investigation also looked into the pilot's experience level and his ability to identify developing meteorological phenomena during flight.