Widespread fatigue damage

Following several widely publicized accidents to transport category aircraft that resulted from undetected structural fatigue, the US Federal Aviation Administration has taken several initiatives under its aging aircraft program. These initiatives are intended to address concerns that the initial maintenance programs for some of these aircraft may not fully take into account that the aircraft are experience longer service lives than originally anticipated and be operated beyond their original Design Service Goals (DSG).

Most recently, the FAA has issued a final rule, amending FAA regulations to require design approval holders for certain transport category airplanes to establish limits of validity (LOV) of the engineering data supporting their structural maintenance program. Operators of affected aircraft may not fly the aircraft beyond their LOV unless an extended LOV is approved. Further details on the FAA rule may be found at: 

Since there is currently no mechanism in Canada to limit the operation of aircraft to their DSG, Transport Canada has conducted a Risk Assessment into the potential for adopting the FAA approach. ATAC was among the various industry stakeholders who participated in this risk assessment, which among other things considered the unique circumstances of operation in the Canadian North, where in some cases the only suitable aircraft are older types that may be affected by the imposition of an LOV.

For more information on this subject, please contact:

Les Aalders
Executive Vice President