| Abstract Scope |
On April 17, 2018, Southwest Airlines flight 1380 experienced a fan blade fracture and subsequent loss of the engine inlet and cowling in the left CFM International CFM56-7B turbofan engine. Fragments from the engine inlet and fan cowling struck the wing and fuselage, resulting in a cabin depressurization. The flight was diverted to Philadelphia, Pennsylvania. One passenger died and eight passengers received minor injuries. Nearly sixteen months earlier on August 27, 2016, another accident had occurred involving a fractured fan blade on another CFM56-7B turbofan engine. In each accident, a Ti-6-4 fan blade fractured at its root, and fractography at the National Transportation Safety Board’s Materials Laboratory revealed fatigue fracture features. Striation counts and residual stress measurements provided clues to fatigue crack initiation and propagation. Information about the fan blade failures that became part of the public record ahead of a November 14, 2018, public hearing will be presented. |