What happened
On August 6, 2020, a Socata TB9 Tampico, registration CS-DAB, was conducting a flight from Cascais to Coimbra for the purpose of visiting a maintenance facility. Approximately five minutes after departing Cascais, while flying at 1,000 feet and performing a right turn, the engine began operating irregularly and lost power.
Unable to maintain altitude, the pilot declared a MAYDAY and searched for a suitable landing site. The pilot selected a nearby golf course for an emergency landing. During the final approach, a tailwind component contributed to a bounced landing. The aircraft struck two large trees; the left wing separated from the fuselage upon the first impact, and the fuselage and right wing struck a second tree. The aircraft traveled approximately 265 meters before coming to a stop. There were no injuries to the pilot or the two passengers on board.
The investigation
The GPIAAF investigation focused on the engine failure and the circumstances of the emergency landing. Investigators examined the aircraft's fuel system, the maintenance history of the aircraft, and the pilot's emergency management. The investigation also reviewed the impact of cockpit resources, noting that the two passengers, who were also flight instructors, provided suggestions regarding the landing site that placed additional pressure on the pilot's decision-making process.
Findings
- The primary cause of the engine power loss was fuel contamination, specifically the presence of water in the fuel.
- The pilot's emergency management deviated from the manufacturer's procedures; the fuel selector was set to the left tank and the auxiliary fuel pump was left off. Had the right-hand tank been selected and the auxiliary pump activated, the engine might have continued to run despite the water content.
- The aircraft's configuration during landing (flaps retracted) was not in accordance with the Pilot's Operating Handbook (POH).
- The presence of passengers influenced the pilot's decision-making during the emergency.
- The aircraft had undergone recent maintenance and ownership changes, including painting and inspections, prior to the flight.