What happened
On September 18, 2025, a Cessna 551 aircraft, registration YV1776, was operating a flight from Oscar Machado Zuloaga International Airport in Charallave to Santa Elena de Uairén. The aircraft was carrying two crew members and four passengers.
While cruising at FL 270, the crew detected vibrations in the number two engine. The pilot initially attempted to return to the departure airport by reducing power to the minimum setting. However, after approximately ten minutes of flight, the vibration in the second engine increased. Following the procedures outlined in the Quick Reference Handbook (QRH) without success, the crew declared an emergency and diverted to the nearest suitable airport, Ciudad Bolívar. The crew proceeded to shut down the affected engine and descended to traffic levels. The aircraft landed safely in Ciudad Bolívar with no injuries to the occupants.
The investigation
The JIAAC conducted a physical inspection of the aircraft and its components. Investigators examined the engine, the oil filter, and the N1 rotor assembly. The investigation included interviews with the flight crew and a review of maintenance records from the operator, INVERSIONES 2567P C.A., and the maintenance organization responsible for the last scheduled services.
Findings
Technical inspections of the engine revealed several critical issues:
- The oil filter contained abundant metallic and non-metallic contamination, along with unusual coloring in the oil cover.
- Magnetic particles were found in high quantities within the filter.
- Visual inspection of the N1 rotor assembly showed slight contact between the fan and the engine case.
- Axial play was observed on the fan shaft.
- Manual rotation of the fan produced an unusual sound near the number 1 bearing, characteristic of dry metal-to-metal friction.
All evidence points toward premature damage to the number 1 bearing within the N1 rotor assembly as the primary cause of the vibration.