This handbook documents engineering methodologies for the development of standardized, statistically -based material property data for polymer matrix composite materials. Also provided are data summaries for a number of relevant composite material systems for which available data meets specific MIL-HNBK-17 requirements for publication. Additionally, supporting materials are summarized. This handbook has been developed and is maintained as a joint effort of the Department of Defense and the Federal Aviation Administration. The book's primary purpose is the standardization of engineering data development methodologies related to characterization, testing, data reduction, and data reporting of properties for composite material systems for which data meeting specific requirements is available.