What happened
On September 19, 1999, a Robin HR 200-160, registration HB-KFA, departed from Bex, Switzerland, bound for Cannes, France. The flight was a VFR cross-country trip carrying a pilot and one passenger. After refueling, the pilot planned a route via Alpe-d'Huez and Gap, noting that weather conditions appeared favorable for most of the route, though the Alpine sector was noted as a point of concern.
During the flight, near Entrevaux, the aircraft encountered rapidly deteriorating weather conditions. Heavy rain showers caused visibility to drop and the cloud ceiling to lower. Unable to continue the original route, the pilot attempted to turn back but found the path blocked by the weather. The pilot then sought an alternative destination at the private airfield in Puimoisson. After approximately 25 minutes of searching for a clear path through the weather, the pilot decided to perform a precautionary landing in a field to avoid running out of fuel. Following a reconnaissance approach, the aircraft landed in the field, but during the landing roll, the aircraft struck an earthen mound, resulting in damage to the landing gear and the left wing.
The investigation
The investigation focused on the circumstances leading to the decision to perform a forced landing and the impact of the meteorological conditions on the flight path. The investigators examined the pilot's pre-flight weather assessment, the flight plan, and the actual weather conditions recorded at the time of the accident, including data from the Saint-Andréles-Alpes automatic station and various METAR/TAF reports for the region.
Findings
- The primary cause of the accident was the insufficient consideration of weather forecasts during flight preparation.
- While the pilot identified potential issues in the Alpine sector, the rapid degradation of visibility and cloud ceiling during the flight exceeded the pilot's ability to navigate safely to the intended destination.
- The decision to land in a field was driven by the necessity to avoid an engine flameout due to fuel exhaustion.
- The damage to the Robin HR 200-160 was caused by the aircraft striking a mound of earth during the landing roll.