What happened
On August 5, 2009, at 08:32 UTC, an Airbus A320-211, registration EC-ICQ, operated by Vueling Airlines, was preparing for a scheduled international flight from Paris Orly to Alicante, Spain. During the engine start sequence, the crew began the startup of the number two engine. Approximately 45 seconds later, ground personnel reported a localized fire in the engine, and an 'ENG2 START FAULT' message appeared on the ECAM.
As the flight crew requested assistance from airport fire services, a ground agent attempted to suppress the fire using a powder extinguisher. Although the fire appeared to be extinguished shortly before 08:35, a white cloud of powder created the impression that the fire remained uncontrolled. Consequently, the commander ordered an emergency evacuation via the slides. The evacuation was conducted through the forward left and rear doors, while the forward right door was kept closed. During the process, twelve passengers sustained minor injuries.
The investigation
Investigators examined the engine cowlings and discovered soot, burns, and a fuel leak originating from a T-fitting in the low-pressure circuit. The investigation focused on the Air Turbine Starter (ATS), which had sustained significant damage, including a broken blade, fatigue cracking on the disk and over half of the blades, and destroyed bearings.
Technical analysis revealed that the ATS stator had been replaced in November 2008 with a Parts Manufacturer Approval (PMA) component. This PMA stator featured a different geometry and a rougher surface finish compared to the original part, including a residual casting ridge that acted as a turbulator. Additionally, the investigation found that the fuel leak was caused by the insufficient tightening of a T-fitting nut.
Findings
- The primary cause of the incident was the installation of a PMA starter component whose aerodynamic compatibility was not demonstrated. The altered airflow from the PMA stator likely induced transient resonance and fatigue stresses, leading to the failure of the turbine blades.
- The failure of a blade caused an imbalance that destroyed the bearings, releasing high-temperature fragments that ignited accumulated fuel.
- A secondary contributing factor was a fuel leak resulting from an insufficiently tightened T-fitting.
- The use of a powder extinguisher by ground personnel created a white cloud that likely misled the crew into believing the fire was still active, prompting the evacuation order.