The Aviation and Space Dictionary is the second of a series of Chinese-English technical dictionaries under preparation by the Foreign Technology Division, United States Air Force Systems Command. The purpose of the series is to provide rapid reference tools for translators, abstracters, and research analysts concerned with scientific and technical materials from Mainland China. This dictionary contains about 28,000 terms selected from sources published in Mainland China. The terms included relate not only to general aviation, aeronautical engineering, rocket engines, astronavigation, etc., but incorporate vocabulary from the basic sciences and the auxiliary technologies closely associated with aviation and space, such as, telecommunications, metallurgy, welding, aircraft construction, etc. The special features of this dictionary are Mainland Chinese practice in regard to: (1) terminology, (2) style of characters, (3) complete alphabetic lookup by means of the 'pinyin' spelling. Characters in some of the terms have been regrouped for optimum clearness and suitability for computer processing. The terms in this dictionary also incorporate those from Aviation and Space, Volume I, compiled at the Library of Congress. Other subject areas in the series will cover general and nuclear physics, electronics and telecommunications, rocketry, automation and computer technology, surveying, mapping, and meteorology.