Lesson Two Cloze Fill in the blanks with the following given words. (填入对应字母,不填单词) A. digital computers B. feedback C. philosophy D. complex E. reliability F. leading edge G. actuated H. excessive I. performance J. pilot controls Flight Control System As aviation matured and aircraft designers learned more about aerodynamics, the industry produced larger and faster aircraft. Therefore, the aerodynamic forces acting upon the control suces increased exponentially. To make the control force required by pilots manageable, aircraft engineers designed more 1.______ systems. At first, hydro-mechanical 液压机械式designs, consisting of a mechanical circuit回路 and a hydraulic circuit, were used to reduce the complexity, weight, and limitations of mechanical flight control systems. As aircraft became more sophisticated, the control suces were 2.____ by electric motors电马达, 3._____ , or fiber optic cables.光纤线缆 Called “fly-by-wire,” 电传this flight control system replaces the physical connection between 4.____ and the flight control suces with an electrical intece. In addition, in some large and fast aircraft, controls are boosted by hydraulically or electrically actuated systems. In both fly-by-wire and boosted controls, the feel of the control reaction is fed back to the pilot by simulated means. Current research at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center involves Intelt Flight Control Systems (IFCS). The goal of this project is to develop an adaptive neural network-based flight control system. Applied directly to flight control system 5.____ errors, IFCS provides adjustments to improve aircraft performance in normal flight as well as with system failures. With IFCS, a pilot is able to maintain control and safely land an aircraft that has suffered a failure to a control suce or damage to the airframe. It also improves mission capability, increases the 6.____ and safety of flight, and eases the pilot workload. Today’s aircraft employ a variety of flight control systems; however, the 7.____ of flight controls is the same. Aircraft flight control systems consist of primary and secondary systems. The ailerons, elevator (or stabilator), and rudder constitute the primary control system and are required to control an aircraft safely during flight. Wing flaps, 8.____ devices, spoilers, and trim systems constitute the secondary control system and improve the 9.____ characteristics of the airplane or relieve the pilot of 10.____ control forces.