Preliminary Report: Cessna 152 Emergency Landing in Agricultural Field, Chile

Incident Overview and Location On March 22, 2025, at 12:02 local time, a Cessna 152 aircraft made an emergency landing in a flat agricultural field in the Chahuilco sector of the Río Negro commune, Los Lagos Region, Chile. The incident occurred at coordinates 40°44′08.1″ S and 73°12′02.0″ W, approximately 10 nautical miles from the departure aerodrome and 12 nautical miles from the destination. The site featured long grass, a slight incline, surrounding trees, and high-voltage towers. ## Flight Details and Occupants The flight departed from Purranque Aerodrome (SCPR) at 11:00 local time, piloted by a private pilot accompanied by another private pilot holding a flight instructor rating. The purpose of the flight was a periodic standardization flight under visual flight rules (VFR). At 11:15 local time, the crew filed a flight plan with Osorno Tower, indicating a destination of Osorno and a planned touch-and-go landing at Cañal Bajo Aerodrome (SCJO). During the subsequent takeoff from SCJO, the aircraft experienced a progressive decrease in engine power, indicated by a drop in revolutions per minute (RPM). The pilot in command decided to make an emergency landing in the agricultural field. Both occupants were unharmed, and the aircraft sustained no damage. ## Maintenance and Fuel Findings The aircraft was operated by an aeroclub classified as Grade III, approved by the Chilean Directorate General of Civil Aviation (DGAC) for maintenance and annual inspections. The most recent annual inspection was completed on February 5, 2025, at 6,234.8 service hours, with no discrepancies recorded regarding the fuel system, air filter, or carburetor. Fuel samples drained from both wing tanks showed no water or sediment, and the fuel was identified as 100 LL aviation gasoline, the manufacturer-recommended type. ## Aircraft Inspection and Engine Testing A physical inspection at the site confirmed the aircraft was intact and undamaged. The engine oil level was 5 quarts (maximum 6 quarts), with no oil leaks, and the air filter was in good condition. Ground functional tests revealed that the engine could not exceed 1,200 RPM (normal range: 1,900–2,550 RPM) and exhibited symptoms of an excessively lean mixture. After replacing the carburetor with a serviceable unit, the engine achieved 2,300 RPM, and subsequent tests showed normal magneto drop, idle RPM, and oil pressure. ## Probable Cause and Investigation Status The investigation is currently in the information review stage. The removal of the carburetor revealed the presence of carbon and foreign material in the fuel mixture metering valve and injector, which is consistent with the observed loss of power. No final cause has been determined.