This book has been prepared as a source of data and procedures for use in the sizing of both airframe and space vehicle structures. The material presented herein has been compiled largely from the published data of government agencies, such as NACA reports and technical publications. The reader will not, of course, be able to read this book with complete comprehension unless he is familiar with the basic concepts of strength of materials and structural analysis; it is assumed that the reader is familiar with these subjects and such material generally is not repeated herein. To maintain the compact size of this book, only data and information relevant to airframe structures are included. Since today's airframe structures are primarily constructed from metallic materials, this book focuses on metallic structural sizing. A few material allowables are included for reference and for in performing the sizing examples.