What happened
On November 14, 2010, a PA-28-181 aircraft, registration D-EREU, was conducting a VFR night flight from EDXF to LHTL. During the flight within the Prague FIR, the pilot encountered a fuel delivery issue from the right wing tank. After exhausting the fuel from the auxiliary tank, the pilot attempted to switch to the right wing tank, but the engine power dropped and fuel pressure fell to zero, indicating a total loss of fuel supply from that tank.
As the aircraft's fuel supply became critically low, the pilot declared an emergency landing. While attempting to reach Brno/Tuřany (LKTB), the engine eventually failed due to complete fuel exhaustion. Faced with a lack of visibility and limited options at night, the pilot attempted an emergency landing on the R43 highway. During the maneuver, the left wing struck a streetlamp pole and the left main landing gear hit a highway median barrier. The impact caused significant damage to the left wing, nose gear, and propeller, though the pilot and passenger escaped without injury.
The investigation
The ÚZPLN investigation focused on the aircraft's fuel system and the circumstances leading to the engine failure. Investigators discovered that the aircraft had recently undergone an unauthorized modification to install an auxiliary fuel tank in the cockpit area. This work was performed by the crew and others without the required EASA Supplemental Type Certificate (STC) and without certified maintenance personnel.
Technical analysis revealed that during this unauthorized installation, the fuel hoses connected to the auxiliary fuel selector valve were swapped. This error meant that when the pilot attempted to draw fuel from the right wing tank, the system was actually only capable of drawing from the auxiliary tank, effectively isolating the right wing tank from the engine. Furthermore, the investigation found that the pilot's pre-flight functional test of the fuel system was performed using an incorrect procedure that failed to verify fuel delivery from all available tanks.
Findings
- The primary cause of the accident was a series of errors by the pilot and others involved in the unauthorized modification of the fuel system, which failed to detect the incorrect hose connection.
- The pilot's pre-flight testing procedure was insufficient to verify the functional integrity of all fuel paths.
- Inadequate communication between the pilot and Air Traffic Control (ATC) regarding the severity of the fuel shortage and the imminent engine failure hindered more effective assistance from controllers.
- The unauthorized installation of the auxiliary tank lacked the necessary EASA STC.
- Nighttime flying conditions significantly contributed to the difficulty of the emergency situation.