Arne Vollan studied aeronautical engineering at the Technical University of Trondheim (Norway) and Aachen (Germany), and holds the degree Diplom Ingenieur. He was employed by several aeronautical companies such as VFW-Fokker (now Airbus), Helicopter Technik Muenchen, Dornier, Nationaal Lucht- en Ruimtevaartlaboratorium, and Pilatus Aircraft as a dynamic and aeroelastic specialist. He was also a consultant and developed programs for the analysis of rotating structures like wind turbines and propellers. Since 2002 he has been working at AeroFEM GmbH in Switzerland on rotor dynamics and the aeroelasticity of aircraft and large wind turbines.Louis Komzsik is a graduate of the Technical University of Budapest with an engineering degree and the Eötvös University of Sciences in Budapest with a mathematics degree, and he holds a Doctorate from the Technical University of Budapest, Hungary. He was employed by the Hungarian Shipyards from 1972 to 1980 and worked at the McDonnell-Douglas Corporation in 1981 and 1982. He was the chief numerical analyst at the MacNeal-Schwendler (now MSC Software) Corporation for two decades. Since 2003 he has been the chief numerical analyst at Siemens PLM Software. For the past 30 years he has been the architect of the modern numerical methods of NASTRAN, the world’s leading finite element analysis tool in structural engineering.