What happened
On December 13, 2001, at 13:15, a Mooney M 20 J, registration F-BYAS, crashed into an agricultural hangar atop a hill near Sainte-Christie-d’Armagnac. The flight originated from Lognes for a private trip to Nogaro, conducted under Visual Flight Rules (VFR).
During the flight, the pilot received weather updates from air traffic control indicating freezing fog and low visibility in the Mont-de-Marsan and Nogaro regions. While the pilot initially expressed intentions to divert to Pau if conditions deteriorated, they continued toward the destination. Shortly before the accident, the pilot attempted to contact a contact at the Nogaro aero club via mobile phone, but the call was disconnected before any information could be exchanged.
The investigation
The investigation established that the aircraft struck the hangar at an altitude of approximately 133 meters. Radar tracking showed the aircraft followed a direct route to its destination, and engine performance was confirmed to be functional up to the moment of impact. Analysis of the wreckage revealed that the aircraft had entered the cloud layer without a loss of control, with the landing gear found in the early stages of extension and the flaps set to the first notch.
At the time of the accident, local weather was characterized by heavy fog and an overcast ceiling at only 100 feet, with visibility between 800 and 1200 meters. The investigation also noted the presence of three GPS units on board, one of which remained functional after the crash, which the pilot used for navigation due to the lack of radio navigation aids at Nogaro.
Findings
The investigation identified several contributing factors that led to the overconfidence of the pilot, which prevented a timely diversion to Pau:
- The pilot was highly familiar with the Nogaro airfield and its surroundings.
- Much of the flight had been conducted in good weather conditions, and the pilot frequently flew the Lognes-Nogaro route.
- The thinness of the cloud layer at the arrival point may have allowed intermittent glimpses of the ground.
- The use of GPS technology likely reinforced the pilot's confidence and impaired the decision-making process regarding the necessity of a diversion.