What does the FAA Say about Limit of Validity?

The limit of validity (LOV) represents an operational limit based on fatigue test evidence that supports the maintenance program. The FAA defines the LOV as “the period of time (in flight cycles, flight hours, or both) up to which it has been demonstrated by test evidence, analysis and, if available, service experience and teardown inspections, that widespread fatigue damage will not occur in the airplane structure.” It is further defined as the point in the structural life of an airplane at which there is significantly increased risk of uncertainties in structural performance and probable development of WFD.

Once the airworthiness limitations containing the LOV are approved by the FAA, an airplane may not operate beyond the LOV.