PILATUS PC-21 - A damage tolerant aircraft

Abstract

The PC-21 Advanced Trainer was designed and certified as a damage tolerant aircraft. The PC-21 is certified to the acrobatic category of FAR 23 Amendment 23-54. Some major certification aspects are addressed in this paper. The design fatigue spectrum was created based on pilot input in a deterministic manner. The distribution of vertical acceleration was shown to result in fatigue damage similar to FALSTAFF. The aircraft inspection intervals were defined by crack growth analyses, whereas results of the FSFT were taken into account. The Full Scale Fatigue Test (FSFT) was performed by considering a life scatter factor of 3. First, two lives of durability testing were performed. After introduction of artificial damages another life of damage tolerant testing was run. Finally, a residual strength test campaign was carried out. The certified Fatigue Monitoring System (FMS) allows monitoring the loading history of major structural assemblies by means of strain sensors. Several Fatigue Indices are calculated from the strain signals on a flight-by-flight basis for Individual Aircraft Tracking purposes (IAT). © Springer Science+Business Media B.V. 2009.