This part covers a section of avionics that deal with navigation and communication; it also covers the electronic devices that use avionics features. Constituents in the electrical navigation and communication systems are reflected as aircraft devices, and such can only be renovated FAA-standardized repair site or the original assemblers. Specialists must have the necessary permissions from the Federal Communication Commission to do specific radio aerials processes (Crichton). Every radio receiver mounted in a plane used for intercontinental trips must have an FCC-issued wireless station permit, and the license should be shown on the aircraft (Crichton).
Radio is a way of conveying brainpower from one position to another by electromagnetic radiation means. The process by which intelligence is loaded on a carrier is called modulation, and there are multiple ways to do it. In aviation communication instruments, only three are most common: frequency modulation, amplitude modulation, and single-sideband (Crichton). Amplitude modulation is a way in which the audio signal alters the power of the transporter.
Frequency modulation aids in acquiring communication that is free from any interference. Such interferences may be natural, for example, lighting in the atmosphere or human-made like electric motors. SSB is good because it eliminates a single sideband in the transporter, and in return, all the transportation voltage is used in the outstanding sideband. SSB signal also inhabits a reduced percentage of the frequency band, unlike FM and AM, which need a more significant portion of the frequency spectrum (Crichton). Magnetic and electric waves are components of radio waves, and they are right-angled to each other during propagation. Radio waves are carried from the antenna in three parts, depending on their frequency.
Necessary Instruments in Communication Systems
The antenna is one of the instruments used; it is an electrode linked to a radio carrier to radiate the electromagnetic energy generated by the aerial into space. Antennas are suitable for transmitting because they are good at receiving. When selecting an antenna, its polarization, length, and directivity are vital to check (Crichton). It should be half the wavelength, dipole, and its electric field should be vertical and the magnetic field horizontal. For a transmitter and a receiver to get the maximum amount of power into their antenna and receiver antenna, respectively, the antennas should be linked into a particular type of electrode called coaxial cable (Crichton). Coaxial cable is a transmission line also vital in the communication system.
A coax cable must be matched to the transmitter and the antenna or receiver. Coax is rugged, but it should not be left to overheat, and the diameter radius must be bent ten times smaller than the cable diameter. Communication Radio antennas are vital instruments; they have modernized tuned antennas that form part of the plane structure (Crichton). They are used for HF communications, unlike in the past where they used long-wire trailing antennas.
Electronic Navigation Systems
Traveling by air became practical when pilots could navigate without relying on visual recognition of landmarks thanks to Radio Navigation. Low-frequency, four-course wireless range was the earliest radio Navigation system (Crichton).
Radio Transmitters were stationed along the selected Federal airways on the airport. When landing at an airport with the system, the pilot would tune the receiver to the wireless range frequency to locate the station. An alignment design was flown until the pilot perceived the frequent sound and diverted towards the station (Crichton). The main disadvantage of this system is that it worked under low frequency that it was highly prone to atmospheric static, and during bad weather, it was unreliable. It also required a highly skilled pilot as disparities in signal strength could lead the pilot to unsafe topography.
Important Instruments in Navigation
Radio Magnetic Indicator is a vital instrument panel developed to pool information from different indicators to make their interpretation easier. It is a widely used device that chains the remote showing compass with the pointers for the ADF and VOR. A flux-gate compass pushes the dial of the devices, and the head of the VOR pointers points to the TO direction to the station (Crichton). ADF compass indicates the location relative to the front of the aircraft, which is the top of the pointer.
An instrument landing system is also vital as it ensures that pilots step on the ground once they have reached their destination. It has electronic components that aid in its efficiency: localizer, marker beacons, glide slope, and compass radars for middle and outer markers. Compass locators are mounted at the center and outer marker, and they transmit a frequent carrier and keyed identifier with a range of about 15 miles (Crichton). A localizer provides direction down the stretch centerline of the instrument runway roughly 18 miles out to the touchdown location.
Marker beacons are located between four and seven miles from the end of the runway. The outer marker gives a series of dashes to show where the pilot should land. Glide slopes transmit guiding signals about 1.4 degrees extensive and are angled upward from the spreader at an angle of 3 degrees. Finally, the Radar Beacon Transponder is the most vital instrument in controlling a plane along with the busy terminals or airways. With the numerous aircraft in the air at any time, air traffic regulators need to locate the dots on the scope made by a particular plane.
Work Cited
Crichton, Michael. Airframe. Knopf, pp. 797-867.