What happened
On September 29, 2021, at 22:45 UTC, a McDonnell Douglas MD-83, registration YV3465, operated by LASER Airlines, departed from Maiquetia International Airport (SVMI) for Punta Cana, Dominican Republic. During the climb to a cruise altitude of 8,000 feet, the crew experienced heavy vibration originating from the left engine.
The flight crew monitored engine parameters and determined that while all readings remained within normal limits, reducing power to the left engine mitigated the vibration. The pilot in command notified air traffic control of the intent to return to the departure airport due to the vibration but did not declare an emergency. The aircraft landed safely at SVMI with no injuries and no damage to the airframe.
The investigation
The JIAAC investigation involved reviewing flight documentation, including weight and balance, passenger manifests, and maintenance records. Investigators interviewed the crew and performed a visual inspection of the aircraft structure and the left engine.
Data from the Flight Data Recorder (FDR) was analyzed to verify operational parameters, confirming the crew's account of the vibration. Although the aircraft lacked engine vibration sensors, the FDR data aligned with pilot testimony. A borescope inspection of the removed left engine revealed significant internal damage. The engine has been placed in the custody of the investigating authority for further analysis.
Findings
Physical inspection of the left engine identified that a turbine blade in the first stage had fractured halfway from its root. This failure caused the detached section to strike and damage numerous blades in the first stage, which subsequently caused secondary damage to the turbine blades and stators in stages 2, 3, and 4. Additionally, investigators found evidence of foreign object damage (FOD) on the fourth-stage turbine blades and metallic debris within the nozzle, along with the loss of the exhaust cone.
Safety action
The JIAAC issued a preventive measure to LASER Airlines to establish a procedure for disconnecting the Cockpit Voice Recorder (CVR) upon engine shutdown. This is intended to prevent the recorder from capturing ground taxi and maneuvering data, ensuring that the recorded audio focuses on in-flight conditions.