About the Author: Egbert Torenbeek, Delft University of Technology, The NetherlandsEgbert Torenbeek is Professor Emeritus of Aircraft Design at Delft University of Technology.He graduated as an engineer in 1961 at TU Delft and in 1964 he became responsible for teaching the Aircraft Preliminary Design course at the department of Aerospace Engineering. After a sabbatical at Lockheed Georgia Company, he became a senior lecturer and full professor of the Aircraft Design chair at TU Delft, initiating research and teaching in computer-assisted aircraft design.