What happened
On March 11, 2010, a private VFR flight departed from Bonn-Hangelar (EDKB) bound for Schönhagen (EDAZ). The pilot, flying an Avions Pierre Robin R 2160 D, intended to complete the final leg of the journey under night VFR conditions. During the cruise phase at approximately 8,000 ft AMSL, the pilot took several photographs that captured a yellow warning light on the annunciator panel, indicating a drop in electrical system voltage.
As the flight progressed, the aircraft's electrical supply continued to degrade. Radar tracking confirmed a sequential failure of the transponder, radio, navigation instruments, and aircraft lighting. Simultaneously, weather conditions deteriorated, with cloud ceilings dropping to approximately 750 ft in the destination area. Following a recommendation from Bremen Radar to divert to Schönefeld or Cottbus-Drewitz due to insufficient visibility, the pilot altered course toward Cottbus.
Approximately 25 NM before reaching Cottbus, the pilot decided to terminate the flight and attempt an emergency landing. While maneuvering near several wind turbines, the aircraft struck the treetops of a pine forest. The impact destroyed the aircraft, leaving the pilot seriously injured. The pilot was able to alert air traffic services via mobile phone, and emergency responders arrived at the scene at approximately 20:40 local time.
The investigation
The BFU examined the wreckage and the aircraft's systems. Investigators recovered a Garmin 150 GPS unit, though flight path reconstruction was not possible from the device. The investigation also reviewed radar tracks, which showed the transition from secondary to primary radar surveillance as the transponder failed. The aircraft's electrical instruments were tested with an external battery the following day and were found to be functioning normally. The voltage regulator was sent to the manufacturer for analysis, but a full assessment was not possible as the generator was unavailable for testing.
Findings
- The aircraft experienced a progressive failure of the electrical system, which led to the loss of essential navigation, communication, and lighting equipment.
- Deteriorating meteorological conditions, specifically decreasing visibility and lowering cloud ceilings, complicated the pilot's ability to maintain visual flight rules.
- The aircraft struck trees during an attempt to land, resulting in the total destruction of the airframe and significant damage to the surrounding forest.