This highly regarded textbook presents the entire process of aircraft conceptual design--from requirements definition to initial sizing, configuration layout, analysis, sizing, and trade studies--in the same manner seen in industry aircraft design groups. Interesting and easy to read, the book has more than 900 pages of design methods, illustrations, tips, explanations, and equations, and has extensive appendices with key data essential to design. The book is the required design text at numerous universities around the world and is a favorite of practicing design engineers. The new fourth edition is enhanced in many areas, with improvements and reworking of the text, expanded sizing and analysis methods, and up-to-date treatments of emerging technologies and concepts. A new section provides an introduction to spaceflight and rockets including thrust analysis and vehicle sizing for launch and planetary missions. Appendices are revised and additional exam questions are provided.