Incident Overview
On April 25, 1999, at approximately 09:36 local time, a single-engine Avions Pierre Robin DR 400-180 S crashed into an orchard near Friedrichshafen, Baden-Württemberg, Germany. The aircraft was operating under visual flight rules from Sion, Switzerland, to Friedrichshafen for an airshow. All four occupants, consisting of a flight instructor, two students, and one passenger, were killed in the impact.
Flight Progression
The flight departed Sion at 08:00 MESZ with a planned duration of 1 hour and 42 minutes. The aircraft followed a route via Martigny, Bex, Spiez, Meiringen, Brunnen, Wangen/Lachen, Wil, and Konstanz. At 09:25, the pilot reported being over Konstanz and heading for the mandatory reporting point ILMENSEE. Three minutes later, air traffic control instructed the pilot to proceed directly to the NOVEMBER reporting point. The aircraft reached NOVEMBER at approximately 2,400 ft MSL after 1 hour and 32 minutes of flight time.
Approach and Impact
Upon entering the Friedrichshafen control zone, the pilot was instructed to fly a right base approach as close as possible to runway 24. At 09:36, the pilot received instructions to turn onto the final approach, which were acknowledged. Shortly after, the aircraft rolled into a right bank and impacted the ground at low altitude in an orchard located approximately 600 meters before the threshold of runway 24. Witnesses reported seeing the aircraft in a steep right bank; one heard no engine noise, while another heard stuttering engine sounds.
Investigation Findings
The investigation revealed that the main fuel tank was empty and damaged, while the left auxiliary tank contained approximately 25 liters of fuel. The fuel selector switch was found in the position for the main tank. Fuel lines from the selector to the carburetor were broken. The engine itself showed no mechanical defects prior to impact, but evidence suggested it had little or no power at the time of the crash. The aircraft was slightly overweight for landing by approximately 7 kg. No technical faults were found in the airframe. The pilot held valid licenses and had recently undergone a heart bypass operation, though no acute medical event was confirmed during autopsy.