Widespread fatigue damage ( WFD ) in a structure is characterised by the simultaneous presence of cracks at multiple points , that are of sufficient size and density such that , the structure will no longer meet its damage tolerance requirement and could fail . For example , small fatigue cracks developed along a row of fastener holes coalesce , this moves to adjacent sites and propagates . The objective of a designer is to determine when large numbers of small cracks could degrade the joint strength to an unacceptable level . The in-flight loss of part of the fuselage from Aloha Airlines Flight 243 was attributed to multi-site fatigue damage
Aloha Airlines Flight 243
Aloha Airlines Flight 243
Widespread fatigue damage