What happened
On July 5, 2009, a Cessna 152-II, registration EC-DNN, was conducting a private VFR flight from Granada Airport to Almería Airport. The aircraft was operated by Gesplane and carried a pilot and one passenger. During the return leg of the flight, while cruising at 4,500 feet, the pilot noticed the engine began losing power.
Unable to restore power, the pilot attempted emergency procedures, including adjusting the mixture and using the choke. The pilot also performed banking maneuvers to attempt to stabilize fuel flow. Ultimately, the pilot selected the A-44 highway near El Padul as a landing site due to the low traffic volume at the time. The aircraft landed on the highway; while the engine continued to run at low RPM, it could not provide sufficient power. The pilot and passenger were uninjured, and there was no damage to the aircraft or third-party property.
The investigation
The CIAIAC investigation examined the aircraft's mechanical condition, maintenance records, and the pilot's actions. Investigators found that the left fuel tank was empty, while the right tank contained approximately 20 liters of fuel. Crucially, the cockpit fuel gauges provided inaccurate readings, significantly underreporting the actual fuel levels.
Technical inspections revealed several maintenance deficiencies. The throttle friction knob was loose, causing RPM fluctuations, and the mixture control was improperly secured to the instrument panel. The ignition switch was also loose enough to be removed even while the engine was running. Additionally, investigators found corrosion in the fuel filter, a detached rubber plug within the gascolator, and a lack of sealant at the carburetor intake connection.
Findings
- The pilot failed to perform a visual fuel quantity check during pre-flight inspections, relying instead on inaccurate cockpit gauges.
- The left fuel tank was empty, leading to the power loss.
- The pilot's use of banking maneuvers may have contributed to the engine failure by disrupting fuel flow from the remaining fuel in the right tank.
- The aircraft's maintenance was found to be deficient, evidenced by the loose control levers and ignition switch.
- The cockpit tachometer was malfunctioning, providing fluctuating and unreliable RPM readings.