"The Polish report into the crash found the shaft bearing in the engine had been installed with half the required number of roller bearings—13 instead of 26. Its failure caused the inner part of the disc to melt and the outer part to spin freely, destroying itself and becoming a rotary projectile. LOT never bought another Soviet aircraft and took delivery of its first Boeing 767 in 1990. Meanwhile, it fitted its Ilyushin 62M fleet with vibration gauges and warning lights."