What happened
On June 20, 2011, an Airbus A320-212, registration CS-TKJ, operated by SATA International, was performing a commercial flight from Funchal (LPMA) to Copenhagen (EKCH). During the takeoff roll on runway 05, the aircraft encountered a large flock of seagulls at approximately two-thirds of the runway length. The birds struck the landing gear, flaps, and the lower surfaces of the fuselage and wings, with several birds being ingested into both engines.
The ingestion caused intense vibrations throughout the aircraft, with N1 vibration readings reaching maximum values on the ECAM. The crew declared a 'mayday' and requested an immediate return to the airport. To mitigate the vibrations, the crew performed a climbing turn, reduced engine power, and experienced a 1st altitude loss of 150 feet before climbing back to 1,000 feet to execute a landing approach.
During the landing roll, as the aircraft decelerated below 80 knots, the crew received a 'DOOR FWD CARGO' master caution message. Upon reaching the stand, ground staff found the forward cargo door swung open and the handle in the fully unlocked position. There were no injuries to the 7 crew members or 105 passengers, though the aircraft sustained minor damage.
The investigation
The GPIAAF investigation examined the aircraft and the surrounding environment. Inspections of the engines revealed that while there was no visible damage to the intake lips or cowlings, the internal liners had significant blood smears, and 9 fan blades on engine number 2 and 12 fan blades on engine number 1 exhibited tip curl deformation that exceeded operating limits, necessitating replacement.
Regarding the cargo door, investigators found blood smears on the door surface and within the handle recess. While the maintenance provider and the manufacturer found no technical discrepancies or mechanical failures that would explain the door opening, the investigation noted that the door was found in an unlocked state. The investigation also reviewed the airport's bird management strategies, noting that a falconry service had been implemented in 2017 following a study into local bird species.
Findings
- The primary cause of the engine vibrations was the ingestion of multiple seagulls during takeoff.
- The forward cargo door became fully unlatched and open during the flight, exposing it to aerodynamic loads.
- The existing FCOM/ECAM procedures for a 'DOOR FWD CARGO' alert were deemed inadequate for a situation where the door is fully unlatched and subject to aerodynamic forces, as the current procedure only addresses issues related to cabin pressure and airtightness.
Safety action
- Safety Recommendation PT.SIA 2021/006: Airbus should develop a specific crew alert and associated procedure for the A320 family to address the event of a cargo door becoming fully unlatched and open in flight, ensuring aircraft integrity is maintained.