What happened
On January 23, 2019, a Cessna C-152, registration LV-ONO, was conducting a general aviation training flight from Nahuel Aerodrome toward Neuquén International Airport. Approximately 30 minutes into the flight, while cruising at 8,000 feet, the aircraft experienced a sudden loss of engine power characterized by a drop in RPM. This loss of performance made it impossible for the pilot to maintain the flight path or continue to the intended destination.
In response to the engine failure, the pilot executed an emergency landing on National Route 2/37 near Kilometer 1505, close to Piedra del Águila. While the landing on the roadway was completed without incident, the aircraft's right wingtip struck a roadside sign during the rollout, resulting in minor damage to the wingtip fairing.
The investigation
The investigation focused on the mechanical cause of the power loss and the subsequent impact. The crew, consisting of a private pilot and a flight instructor, evacuated the aircraft safely and sustained no injuries.
Technical inspections conducted by maintenance personnel at the scene revealed that two lower spark plugs in cylinders 3 and 4 were heavily fouled. This condition had caused the engine to malfunction. Following the replacement of these components, the engine was verified to be operating within the manufacturer's specified parameters. A temporary repair was also performed on the wingtip to allow the aircraft to be ferried to Neuquén.
Findings
- The primary cause of the engine power loss was the fouled condition of two spark plugs within the ignition system.
- The resulting drop in RPM caused insufficient engine power to maintain the established flight level.
- The impact to the right wingtip was caused by the aircraft striking a road sign during the emergency landing sequence.