What happened
On July 22, 2021, a CESSNA FR172K, registration EC-DCP, was conducting a flight for the purpose of building pilot experience when the aircraft experienced a loss of engine power. The flight departed from Cuatro Vientos airport and was cruising at approximately 4,000 ft near Albalate de Zorita when the power loss occurred.
Upon the loss of power, the pilot handed control of the aircraft to the passenger, who held a higher level of flight experience. The crew attempted to troubleshoot the issue by switching fuel tanks and applying full throttle, but the engine power continued to decline. The passenger subsequently decided to perform a precautionary landing in a fallow agricultural field. During the landing, the uneven terrain caused the nose gear to collapse, resulting in the aircraft flipping onto its back.
Both occupants of the aircraft were uninjured and were able to exit the cabin on their own.
The investigation
The investigation focused on the engine's performance and the maintenance history of the aircraft. Investigators examined the engine and found several minor discrepancies, including worn spark plugs, a loose mixture control cable sleeve, and a non-functional alternative air valve. However, the investigation found that these issues were not capable of causing a sudden drop in engine RPM.
Testing of the fuel system, including the gascolator, showed no obstructions or contamination. The magnetos were found to be providing adequate voltage, and the engine compression was within normal limits. While the investigation noted that the maintenance center had not provided the specific operational test results required after the 100-hour inspection, no conclusive evidence was found to link any mechanical component to the power loss.
Findings
- The primary cause of the accident was the emergency landing in a field due to engine power loss.
- The pilot and passenger failed to complete all steps of the engine failure checklist, leaving it uncertain if power could have been restored.
- The nose gear collapse and subsequent inversion were caused by the pilot's failure to account for the uneven terrain during the landing.
- There was no conclusive mechanical cause identified for the initial loss of engine power.