What happened
On August 28, 2014, a Cessna 210L, registration D-EBAM, was conducting a navigation training flight from Cascais (LPCS) to Faro (LPFR) and back. The aircraft was operated by Leávia – Escola Aviação Civil with an instructor and a student pilot on board. Both fuel tanks had been filled prior to departure.
During the return leg, while descending to FL070 near the Port of Troia, the engine lost power. The instructor pilot initiated troubleshooting and performed a turn toward the Comporta area. After approximately 15 seconds, the engine resumed normal operation, allowing the crew to regain lost altitude. However, at approximately 3,300 feet near Espichel, the engine failed a second time. Finding it difficult to restart the engine, the instructor declared an emergency, preparing for a forced landing between Lagoa de Albufeira and Fonte da Telha.
During the subsequent attempts to recover engine operation, the engine restarted, and the crew was able to climb to 4,000 feet and coordinate with Air Traffic Services (ATS) to maintain that altitude until reaching Carcavelos. During the final approach to runway 35 at Cascais, the aircraft's energy state required heavy braking, which caused one of the main landing gear tires to burst. The aircraft came to a stop on the runway at 12:33 UTC. Both occupants were uninjured.
The investigation
The GPIAAF investigation examined the aircraft's fuel system and pre-flight records. The investigation focused on the fuel management during the flight and the possibility of fuel starvation. The team analyzed the fuel capacity and the actual fuel levels present at the start of the mission.
Findings
- The instructor pilot and student pilot were both properly licensed and medically certified.
- The Cessna 210L is equipped with a fuel system consisting of two independent subsystems with structural wet wings.
- Although the aircraft was recorded as being fueled to "Full," investigation of the fuel levels suggested the aircraft actually started the mission with approximately 241 liters (395 lbs) of fuel, which is near the lower limit of the filling nozzle, rather than the full capacity of 326 liters (534 lbs).
- The engine failures were caused by fuel starvation resulting from the lack of fuel in the tank outlets (unporting).
- The investigation noted that in aircraft with low dihedral, fuel can shift during maneuvers, potentially uncovering the fuel collectors.
- There was no evidence that weather conditions contributed to the occurrence.