Incident Overview
On 23 January 2019, a Cessna C-152, registration LV-ONO, departed from Nahuel Aerodrome in San Carlos de Bariloche, Río Negro, at 16:20 UTC on a general aviation training flight destined for Presidente Perón International Airport in Neuquén. Approximately 30 minutes into the flight, while cruising at 8,000 feet, the aircraft experienced an engine malfunction characterized by a drop in revolutions per minute (RPM). The power loss prevented the aircraft from maintaining level flight or continuing toward its destination.
The pilot executed an emergency landing on National Route 237 at kilometer 1505, near Piedra del Águila, Neuquén. The landing was without incident; however, after rolling about 130 meters, the right wingtip struck a road sign. The impact caused minor damage to the right wingtip fairing.
Both occupants—a pilot and a flight instructor—exited the aircraft unassisted and were uninjured. The emergency was reported to another aircraft from the same flight school that was flying in the area and in radio contact.
Investigation Findings
Personnel from the FlightCenter de Medivac S.R.L. repair station (1B-513) inspected the aircraft at the site. They found that two of the lower spark plugs in cylinders 3 and 4 were heavily fouled, causing poor engine performance. After replacing these spark plugs, the engine operated within the manufacturer’s parameters. A temporary repair of the wingtip was performed to allow the aircraft to be ferried to Neuquén Airport.
Conclusions
The investigation concluded that the engine power loss resulted from the faulty operation of two spark plugs in the ignition system. This power reduction prevented the aircraft from maintaining its flight path, necessitating the emergency landing. The damage to the right wingtip was consistent with impact against the road sign.
Safety Actions
The report recommended that the aircraft owner implement effective monitoring and control of component condition and aircraft airworthiness before they are placed into service, to ensure correct operation.