What happened
On April 30, 2011, a Van's Aircraft RV-8A, registration OY-L**, experienced an engine failure shortly after departing from the EBGB airfield. The aircraft had been climbing to 900 feet when the engine began running roughly for several seconds before stopping completely. The pilot attempted a 180-degree turn to return to the airfield and declared an emergency, but after attempting various troubleshooting steps—including switching fuel tanks and using the emergency fuel pump—the pilot realized the airfield was unreachable.
To avoid further danger, the pilot selected a nearby cultivated field for a forced landing. During the touchdown on the soft ground, the aircraft experienced a 3-point landing that resulted in a stall and a hard impact. While the pilot escaped without injury, the aircraft sustained serious damage, including a bent nose landing gear, destroyed propeller blades, and crushed wing leading edges.
The investigation
The AAIU(Be) investigation focused on the engine's recent modifications and the circumstances of the failure. The engine had recently undergone extensive maintenance and a significant modification to incorporate a FADEC (Full Authority Digital Engine Control) system. This upgrade replaced the original carburetors and ignition system with a digital computer known as an ECU (Engine Control Unit).
Investigators examined the electrical architecture of the ignition system, noting that the installation utilized non-resistor spark plugs and copper high-tension cables that lacked shielding. Furthermore, the investigation found that the power supply wires for the ECU were unshielded. While the engine had been tested on a professional test bench to set parameters, no endurance testing had been conducted prior to the flight.
Findings
- The primary cause of the accident was a limited loss of control during the forced landing following the engine failure.
- The engine failure was likely triggered by the tripping of the ECU due to electrical interference generated by the ignition system.
- The ignition system was highly susceptible to electromagnetic interference because it utilized non-resistor spark plugs and unshielded components.
- The engine modification process lacked sufficient endurance testing on the ground.
- The technical complexity of the engine's digital control modification exceeded the owner's specialized technical expertise.