1. Institute of Materials and Quality Engineering, Faculty of Materials, Metallurgy and Recycling, Technical University of Kosice, Letna 1/9, 04200 Košice, Slovakia
2. Department of Production Engineering, Faculty of Materials Engineering, Silesian University of Technology, ul. Akademicka 2A, 44-100 Gliwice, Poland
3. Department of Air Transport, Faculty of Transportation Sciences, Czech Technical University in Prague, Konviktská 20, 110 00 Prague, Czech Republic