What happened
On May 18, 2001, at approximately 18:30 local time, a Cessna Reims F172E, registration EC-AVL, was conducting a general aviation flight from Málaga to Valencia. The pilot, the sole occupant of the aircraft, had reached a cruising altitude of 10,000 feet without incident. While flying over the vicinity of Jumilla, Murcia, the aircraft experienced a sudden loss of engine power accompanied by intense vibrations. The pilot attempted to increase power, but the engine failed to respond, instead experiencing a further decrease in RPM.
Recognizing the emergency, the pilot initiated a descent to locate a suitable landing site. Although a nearby roadway was visible, the pilot bypassed it to avoid potential hazards from roadside signage. The pilot eventually identified and utilized an unprepared field for an emergency landing. During the landing roll on the uneven terrain, the nose gear collapsed, causing the propeller to strike the ground. The aircraft sustained damage to the nose gear, propeller, engine mount, and the left wing leading edge. The pilot was able to exit the aircraft without injury.
The investigation
The investigation focused on the engine failure and the presence of contaminants in the fuel system. An initial inspection at the landing site confirmed that sufficient fuel remained on board at the time of the incident. However, investigators noted that the mixture control was set to the "lean" position and the carburetor heat was not engaged.
Upon transferring the aircraft to Valencia for a detailed technical examination, investigators found traces of water in the carburetor bowl, though not in quantities large enough to cause an immediate engine shutdown. Further inspection of the fuel system revealed small amounts of water in both the tanks and the fuel strainer. The ignition system and cylinder compressions were found to be within operational limits.
Findings
- The investigation established that the presence of water in the fuel system was due to inadequate fuel system draining.
- The primary cause of the engine performance degradation was the formation of ice in the fuel filter, triggered by the water present in the system, which caused a partial blockage and restricted fuel flow to the carburetor.