Event Description
During the takeoff roll, the flightcrew heard a noise and felt a vibration from the left side of the airplane. As the airplane rotated, a cockpit warning indicated a left engine vibration at Level 5. During the climb, the crew observed smoke and haze in the cockpit, and the cabin crew reported that the cabin was filling with smoke. The flightcrew declared an emergency, performed an immediate landing, and initiated an emergency evacuation.
Investigation Findings
The investigation determined that a turbine blade in the left engine had failed due to a fatigue crack. This failure caused excessive vibration within the engine. The continued vibration led to an oil seal failure, allowing oil to contaminate the bleed air, which produced smoke in the cockpit and cabin.
The failed blade had been mis-marked with the wrong part number by the manufacturer. This error allowed the blade to remain in service far beyond its specified life limit, during which the fatigue crack developed and ultimately caused the failure.