飞机设计导论（第七章）.ppt

Introduction to Aircraft Design
Chapter 7
What’s under the skin?
Avionics, flight control and weapon systems
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隐身技术
Avionics Systems
Avionics is one of the most rapidly developing fields of aircraft design. Its importance and range has increased over recent years and as much as 40% of the cost of new aircraft can be attributed to avionics.
There is a bewildering range of avionics systems, each of which usually requires the use of many acronyms.
Fig. shows an avionics fit for a small executive aircraft.
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Introduction to Aircraft Design
Avionics Systems
Modern efficient, reliable avionics have dramatically simplified the flight operation and have eliminated to need of crew members such as navigator, wireless operator and flight engineer.
The growth in the capabilities of military avionics has been even more dramatic and make it possible for pilot of single-seat aircraft to navigate, communicate, detect and attack targets at heights of 30m and speeds approaching the speed of sound. Fig. and .
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Introduction to Aircraft Design

munications systems vary considerably in size, weight, range, power requirements, quality of operation, and cost, depending upon the desired operation.
The munication system in use today is VHF, large a/c are usually equipped with HF, some are fitted with UHF systems.
VHF (100~150MHz) radio waves follow approximately straight lines. The range of contact is determined by the heights of the transmitting and receiving antennas.
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Introduction to Aircraft Design

Typical ranges are 200 miles (320km) at 20 000ft (6000m) .
UHF systems are similar to VHF but operate in the 200~400MHz band.
HF (2~30MHz) communication system is used for long munication, which operates essentially in the same way as VHF systems.
Communications over long distances are possible with HF radio because of ionospheric reflection.
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Introduction to Aircraft