What happened
On February 22, 2017, an A320-232, registration PT-MZY, operated by TAM Airlines, was performing a takeoff from threshold 17R at Congonhas Aerodrome (SBSP) in São Paulo. The flight was scheduled for regular passenger transport to Confins, carrying 131 passengers and six crewmembers.
As the aircraft reached a speed of approximately 68 knots, a loud noise was recorded, followed immediately by an engine stall warning for the number two engine. The failure of the right engine caused the aircraft to yaw significantly to the right. During the aborted takeoff procedure, the aircraft momentarily exited the right side of the runway. The crew applied left pedal and differential braking to correct the trajectory; however, because the application of the left brake was insufficient to disengage the autobrake, the system applied symmetrical braking, which contributed to the excursion. The crew eventually regained directional control and brought the aircraft to a stop on the asphalt. There were no injuries to the 137 occupants, though the aircraft sustained damage to the right engine and right wing.
The investigation
CENIPA's investigation focused on the mechanical failure of the right engine, an IAE V2/2527-A5. Investigators examined the internal structure of the engine and found that two annulus fillers—components within the fan module—had detached and fragmented. These fragments were ingested into the compressor and turbines, causing significant internal damage, including the breaking of stationary and rotating elements and an excessive increase in Exhaust Gas Temperature (EGT).
Laboratory tests conducted with the assistance of international agencies (BEA, NTSB, JTSB, and BFU) identified potential stress marks on the rear attachment points of the annulus fillers. While investigators could not definitively determine if the failure was caused by a pre-existing microstructural defect or a deformation in the retaining ring, they confirmed the fragmentation of these parts was the primary driver of the engine failure.
Findings
- The right engine failure was caused by the detachment and fragmentation of two annulus fillers.
- The aircraft's excursion from the runway was influenced by the inability to disengage the autobrake via differential braking, leading to symmetrical braking during a critical directional correction.
- The runway surface was wet due to recent heavy rain and thunderstorms in the area.
- The aircraft sustained limited damage to the inner regions of the right engine and minor damage to a flap fairing on the right wing.