The Concise Encyclopedia of Aeronautics & Space Systems is devoted to automatic control of these systems in the widest sense. Automatic control in aeronautics encompasses an enormous field including simulation, active control technology - a huge area including aerodynamics, engine control and aircraft management - air traffic control and management, and of course safety. The aeronautics articles are mainly concerned with civil aviation, but also deal with certain aspects of military aircraft and with systems related to helicopters. Atmospheric effects upon aircraft, and upon landing in particular, are thoroughly examined. The problems encountered in the space environment have been identified and addressed both in space itself and during the launching and re-entry phases. This volume presents complete state-of-the-art information on the design and operation of aeronautics and space systems.