That branch of engineering concerned primarily with the special problems of flight and other modes of transportation involving a heavy reliance on aerodynamics or fluid mechanics. The main emphasis is on airplane and missile flight, but aeronautical engineers work in many related fields such as hydrofoils, which have many problems in common with aircraft wings, and with such devices as air-cushion vehicles, which make use of airflow around the base to lift the vehicle a few feet off the ground, whereupon it is propelled forward by use of propellers or gas turbines. See Aerodynamics, Airplane
Aeronautical engineering expanded dramatically after 1940. Flight speeds increased from a few hundred miles per hour to satellite and space-vehicle velocities. The common means of propulsion changed from propellers to turboprops, turbojets, ramjets, and rockets. This change gave rise to new applications of basic science to the field and a higher reliance on theory and high-speed computers in design and testing, since it was often not feasible to proceed by experimental methods only. See Jet propulsion, Propulsion, Rocket propulsion, Space technology
Aeronautical engineers frequently serve as system integrators of important parts of a design. For example, the control system of an aircraft involves, among other considerations, aerodynamic input from flow calculations and wind-tunnel tests; the structural design of the aircraft (since the flexibility and strength of the structure must be allowed for); the mechanical design of the control system itself; electrical components, such as servomechanisms; hydraulic components, such as hydraulic boosters; and interactions with other systems that affect the control of the aircraft, such as the propulsion system. The aeronautical engineer is responsible for ensuring that all of these factors operate smoothly together.
Aircraft and missile structural engineers have raised the technique of designing complex structures to a level never considered possible before the advent of high-speed computers. Structures can now be analyzed in great detail and the results incorporated directly into computer-aided design (CAD) programs. See Computer-aided design and manufacturing