What happened
On 25 October 2018, an Airbus A320-232, registration EC-MDZ, operated by Vueling Airlines, S.A., was performing the first scheduled domestic flight of the day from Bilbao Airport to Barcelona. The aircraft was carrying 120 persons on board, including 6 crew members.
During the takeoff run on runway 12, both fan cowls from the left engine detached from the aircraft. At the moment of rotation, the flight crew noted an unusual sound, but they did not immediately identify it as a structural detachment. Shortly after takeoff, the crew received an ECAM LGCIU2 FAULT message. After performing the required procedures and assessing the situation, the crew decided to continue the flight to Barcelona.
The crew remained unaware of the detached cowls until the aircraft landed at Barcelona Airport at 00:55 UTC. Upon taxiing to the parking position, the crew began receiving multiple ECAM messages. It was only after disembarking the passengers that the crew was informed that the left engine cowls had separated. Fragments of the cowls were found embedded in the left leg of the main landing gear, and the aircraft sustained minor damage to the fuselage, belly fairing, pylon, and wing structures.
The investigation
The CIAIAC investigation focused on the maintenance activities performed prior to the flight and the subsequent pre-flight inspections. The investigation established that maintenance work had been carried out during the night of 24-25 October, which required opening and closing the fan cowls on the left engine.
Investigators examined the aircraft's technical logs and found that the maintenance technicians had failed to make the necessary entries regarding the opening and closing of these cowls. Furthermore, the investigation reviewed the flight crew's walk-around inspection and the ground personnel's confirmation of the aircraft's status before pushback.
Findings
- The primary cause of the incident was flying the airplane without properly closing and latching the cowls on the left engine.
- The failure to secure the cowls resulted from an improper maintenance operation during the previous night stop.
- The maintenance technicians failed to secure the four latches on the cowls and did not document the work in the aircraft logbook.
- The pre-flight walk-around inspection performed by the captain failed to identify that the cowls were unlatched.
- Ground personnel incorrectly informed the pilots that all covers were closed and latched prior to pushback.
- There were no injuries to the 120 persons on board.