III. Read and translate the text. Choose the best title of the text

• History of Avionics
• Avionics Technology
• Avionics Evolution
• Aircraft and its Avionic Systems
• Avionics Implementation
• Modular Avionics

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The word avionics is short for aviation electronics. The term first was introduced in USA as early as 1950’s to define the systems that uses or depends on electronic technology in the aviation sector. When Wilbur and Orville Wright designed and flew the first powered aircraft on 17 December 1903, it might have been impossible for anyone to believe that the aircraft would become a totally electronic and computerized system in the air. Until 1910, the aircraft was just an automobile in the air, when the first radio contact was made between aircraft and ground. After that, there was a steady advancement in both the machinery of the aircraft and the electronics on it. The Wright brothers used avionics as well: an anemometer to measure airspeed. Soon after that, aircraft were equipped with magnetic compasses, angle of attack vanes, fuel-quantity gauges, etc. At the end of the 1920s, avionics had progressed so much, that the first blind flight and landing was performed: navigation was done solely based on gyroscopes and radio navigation aids. Over the 1930s, radio navigation and landing aids were further developed, and implemented on aircraft.

Avionics comprises electronic systems for use on aircraft, artificial satellites and spacecraft, comprising communications, navigation and the display and management of multiple systems. Avionics and systems are the brains and guts of the modern aircraft. Avionics include pilot-machine interface and computerized control of the aircraft, whereas systems allow aircraft operation and keep environmental control for its occupants.

The first major impetus for use of electronics in aviation occurred during World War II. Communications were maturing and the development of airborne radar using the magnetron and associated technology occurred at a furious pace throughout the conflict. Transistors followed in the late 1950s and 1960s and supplanted thermionic valves for many applications. The improved cost-effectiveness of transistors led to the development of digital aircraft systems throughout the 1960s and 1970s, initially in the military combat aircraft where it was used for Nav/Attack systems.

For many years the application of electronics to airborne systems was limited to analogue devices and systems with signal levels and voltages generally being related in some linear or predictive way. This type of system was generally prone to heat soak, drift and other nonlinearities. The principles of digital computing had been understood for a number of years before the techniques were applied to aircraft. The development of thermionic valves enabled digital computing to be accomplished at the expense of vast amounts of hardware. During the World War II a code-breaking machine called Colossus employed thermionic valves on a large scale. The machine was physically enormous and quite impracticable for use in any airborne application.

The first aircraft to be developed in the US using digital techniques was the North American A-5 Vigilante, a US Navy carrier-borne bomber which became operational in the 1960s. The first aircraft to be developed in the UK intended to use digital techniques on any meaningful scale was the ill-fated TSR 2 which was cancelled by the UK Government in 1965. The technology employed by the TRS 2 was largely based upon solid-state transistors. In the UK, it was not until the development of the Anglo-French Jaguar and the Hawker Siddeley Nimrod in the 1960s that weapon systems began to seriously embody digital computing for use in any airborne application, albeit on a meager scale compared to the 1980s.

Since the late 1970s/ early 1980s digital technology has become increasingly used in the control of aircraft systems as well as just for mission related systems. A key driver in this application has been the availability of cost-effective digital data buses such as ARINC 429, MIL-STD-1553B and ARINC 629. This technology, coupled with the availability of cheap microprocessors and more advanced software development tools, has lead to the widespread application of avionics technology throughout the aircraft.

ARINC 429 is a widely implemented data bus standard within the commercial aircraft avionics industry. It is a point-to-point link between avionics subsystems including digital electronics, navigation systems, and engine control systems. Two buses are used for bi-directional interconnections. In a typical application, ARINC 429 buses transmit the sensor data to the flight management computer and another bus transmits the commands from the flight management computer to the sensors and systems. ARINC 429 data bus supports a data rate of 100 kbps or 12.5 kbps. With limited bandwidth ARINC 429 may not be the best standard for modern avionics architectures. Military avionics use MIL-STD-1553, which supports a data rate of 1 Mbps. In the early 1980s Boeing developed a more capable digital data bus termed Digital Autonomous Terminal Access Communication (DATAC) which later became an ARINC standard as A629. It provides a multi-transmitter data bus supporting a 2 Mbps data rate. It is a relatively expensive and heavy implementation. There is always a constant need for higher data rates between the avionics subsystems. The largest single impact of microelectronics on avionic systems has been the introduction of standardized digital data buses to improve the intercommunication between aircraft systems. Previously, large amounts of aircraft wiring were required to connect each signal with the other equipment. As systems became more complex and more integrated so this problem was aggravated.