Service life of the PZL M28 is computed based on the results of the full-scale fatigue tests of the structure . As the PZL M28 is a commuter category airplane according to the 14 CFR Part 23 and CS-23 regulations, the test objects were: (1) wing and wing load carry-through structure, (2) empennage and attached fuselage structure. Additionally, there were fatigue tests carried out for the landing gear and other selected elements including control system elements. The aircraft load carry-through structure is metallic and the cabin is unpressurized. The fatigue tests were conducted stage-by-stage. As tests progressed, it was possible to extend the aircraft target service life, applying the safe-life philosophy with reference to the primary components of the load carry-through structure.
The article brings into attention selected issues related to the fatigue tests plan preparation, with focus on wing and wing load carry-through structure test.