What happened
On August 9, 2021, a Cessna 152 was conducting a maintenance flight near the Melipilla Aerodrome (SCMP) in Chile. The flight, which included a pilot and a passenger, was intended to cover approximately 135 nautical miles over an estimated duration of 84 minutes. While the aircraft was descending to 2,000 feet to enter the traffic pattern for Melipilla, the engine suddenly lost power and ceased operation completely. Unable to reach the runway or an alternative airfield due to the low altitude, the pilot performed an emergency landing in an agricultural field located roughly 7.9 miles west of the aerodrome. Both occupants were uninjured, and the aircraft sustained no damage.
The investigation
DGAC Chile investigators examined the aircraft's maintenance records, engine condition, and fuel levels. The investigation confirmed that the aircraft had recently undergone a 100-hour inspection and an engine replacement. Physical inspections of the engine, propeller, and fuel system showed no mechanical failures or leaks. Laboratory analysis of the AVGAS 100LL fuel confirmed it was uncontaminated and met all manufacturer specifications. However, investigators noted that the flight duration had extended to approximately two hours, exceeding the original 84-minute plan. Upon inspection of the fuel tanks, investigators found that the remaining fuel levels were extremely low, nearing the unusable limit defined in the pilot's manual.
Findings
- The primary cause of the engine failure was a lack of fuel supply to the engine.
- The aircraft was operating with fuel levels below the manufacturer's recommended threshold (one-quarter tank or less).
- This low fuel level allowed air to enter the fuel lines, which prevented the pilot from successfully restarting the engine in flight.
- The flight duration exceeded the original flight plan, contributing to the depletion of the fuel supply.
- Meteorological conditions and aircraft maintenance status were not contributing factors to the incident.