What happened
On July 8, 2006, a Diamond DV 20 Katana, registration OE-AGG, was performing a local recreational flight near Sabaudia, Italy. The pilot had previously completed a 38-minute flight earlier that day and had commenced a second 30-minute flight with one passenger on board. Approximately 13 minutes after takeoff, a low fuel pressure warning light illuminated. Despite the pilot activating the auxiliary electric pump, the engine continued to malfunction before eventually shutting down completely.
Unable to maintain flight, the pilot was forced to perform an emergency landing in a field roughly two nautical miles from the Sabaable airfield. During the final approach, the aircraft's landing gear struck tree branches, causing the plane to pitch downward. The aircraft then struck an electrical pole with its right wingtip, which induced a pitch-up motion before the plane impacted the ground at a relatively low speed. While the aircraft sustained severe damage, specifically to the rear fuselage, the pilot and passenger were able to exit the aircraft independently without any injuries.
The investigation
The ANSV investigation focused on the fuel system and electrical wiring. Post-accident inspections of the wreckage revealed that the single fuel tank in the fuselage was entirely empty. Although the cockpit fuel gauge had indicated a level between 1/4 and 1/2 during the pre-flight inspection, the investigation found that the gauge was providing false readings.
Technical examination of the fuel level sensor revealed that the electrical cable connections were reversed relative to the aircraft's wiring diagrams. This error caused the gauge to display a 1/4 fuel level even when the tank was empty. The investigation also noted that the identification codes on the wiring were extremely difficult to read due to small font size and degradation over time. Furthermore, the aircraft had been fully refueled that morning, but the cumulative flight time of the day had already exhausted the available fuel supply.
Findings
- The primary cause of the accident was engine failure due to fuel exhaustion.
- The electrical connections to the fuel level sensor were incorrectly installed, leading to inaccurate cockpit indications.
- The wiring lacked a unique connection design that would prevent accidental reversal.
- The aircraft lacked an independent low-level fuel warning light separate from the primary quantity gauge.
- The pilot did not identify the discrepancy between the fuel remaining and the total flight time accumulated since the last refueling.