II. Choose the correct descriptions to the terms mentioned in Ex. I and note the purposes of each system

1.It isgeneral term for components, of complex systems such as aircraft that can be replaced quickly and generally with a minimum of tools. The term derives from maintenance that can be done on the flight line, rather than moving the aircraft into a maintenance facility.

2. It will progressively reshape the avionics industry during the next 15 years. It brings the following benefits to aircraft & equipment manufacturers: independence of software applications and hardware platforms, reduction of verification efforts, reusability of application software, less weight and energy consumption, simpler certification, simpler maintenance & upgrades, simpler diagnostic and new business models.

3. With the emergence of commercial air travel in the late 1920s, the major airlines of the day needed a communications provider to rely on. Appointed by the Federal Radio Commission (later known as the FCC) as the sole licensee, such company was born. Over the years, it has evolved into a dynamic, progressive leader providing engineering solutions in the aerospace and defense, aviation, airports, government, networks, security, and transportation industries with over 150 innovative products and services worldwide.

4. As engine power and speeds increased, more force was needed and hydraulically-boosted controls emerged. In the early 60's, NASA engineers began work on an electrical control system which would provide aircraft engineers with more flexibility in aircraft design and architecture, especially in the placement of control surfaces. Systems matured rapidly, and in 1976 General Dynamics took the bold step of eliminating backup hydromechanical controls from the design of its FBW F-16 Fighting Falcon - making it the first high-performance aircraft to rely completely on electrical wires to relay flight commands instead of the usual cables and linkage controls.

5. It consists of the flight control surfaces, the respective cockpit controls, connecting linkage, and necessary operating mechanisms to control aircraft in flight. The mechanical system is the most basic design used. It was used in early aircraft designs and currently in small airplanes where the aerodynamic forces are not excessive. It uses a collection of mechanical parts such as rods, cables, pulleys and sometimes chains to transmit the forces of the cockpit controls to the control surfaces. The Cessna Skyhawk is a typical example. The hydraulic circuit is made of hydraulic pumps, its assorted parts and the actuators. The actuators are powered by the hydraulic pressure generated by the hydraulic circuit and they convert hydraulic pressure into control surface movements. The servo valves control the movement of the actuators.

Ex. II 1-LRU; 2-ARINC; 3-FCS; 4- FBW; 5-IMA;