What happened
On August 21, 2009, at 07:45 UTC, a SATA (Air Açores) British Aerospace ATP, registration CS-TFJ, was performing a takeoff from Porto Santo Airport (LPPS) bound for Funchal. During the takeoff roll, before reaching 80 knots, the crew detected a failure in the number 2 engine. The Interstage Turbine Temperature (ITT) surged to approximately 1200°C, accompanied by visible smoke and an orange glow emanating from the engine, which was visible to the passengers.
The flight crew responded immediately by aborting the takeoff, bringing the aircraft to a halt on the runway, shutting down the affected engine, and discharging an engine fire extinguisher. Airport emergency services arrived promptly to apply water to the overheating engine.
During the subsequent evacuation, the commander ordered passengers to exit via the rear left door using the emergency slide. However, the slide failed to inflate because the deployment lever had been left in an intermediate position rather than the required "auto" position. Consequently, most passengers jumped directly from the aircraft onto the runway. While most crew and passengers exited via the front slide without issue, one passenger sustained a minor foot injury during the jump from the rear door.
The investigation
The GPIAAF examined the engine components and the aircraft's emergency equipment. An inspection of the number 2 engine, conducted by the manufacturer, revealed that several turbine blades in the first stage had been destroyed. Microscopic analysis of the fracture surfaces was performed to determine the origin of the failure.
Findings
- The engine overheat was caused by the fatigue fracture of turbine blade number 29.
- The investigation identified that the fatigue originated from casting porosity within the blade profile, which eventually led to a final rupture due to tensile overload.
- The failure of blade 29 triggered a chain reaction, causing the destruction of multiple other blades in the first stage of the turbine.
- The failure of the emergency slide was attributed to the deployment lever not being set to the "auto" position.
- The method of evacuation contributed to the single minor injury recorded during the incident.