Incident: Boeing 767-338

The fatigue fracture and liberation of two airfoils from a low pressure turbine stage 5 nozzle segment that impacted and damaged the downstream low pressure stage 5 blades creating an initial imbalance load in the engine’s low pressure turbine rotor sufficient to allow all the low pressure turbine blades to lose radial blade clearance, contact static structure, and to fracture transversely across the airfoil. The progressive failure of the low pressure rotor caused an increasingly imbalanced load that eventually resulted in the fracture of the oil supply tube that allowed oil to contact hot engine parts and smolder and ignite resulting in the undercowl fire.

NTSB docket ENG21LA013

• Ontario International Airport (ONT)0 nm (0 km) eastVoydar estimateGreat-circle distance and initial true bearing between the two airport reference points.Version voydar.air.great_circle v1
• Chino Airport (CNO)5 nm (10 km) southVoydar estimateGreat-circle distance and initial true bearing between the two airport reference points.Version voydar.air.great_circle v1
• Upland-Cable Airport (CCB)5 nm (10 km) north-westVoydar estimateGreat-circle distance and initial true bearing between the two airport reference points.Version voydar.air.great_circle v1