AIRCRAFT COMMUNICATION SYSTEM
CVR (Cont'd)
- The CVR is installed in the aft equipment compartment, and is colored orange for quick identification. An underwater locator device is installed on the unit to aid in unit location if submerged. The device contains an acoustic beacon, battery and a water - activated switch
CVR (Cont'd)
Radio Communications
COCKPIT VOICE RECORDER SYSTEM
A CVR control panel is located on the right side console and includes:
- Test Button
- Test Lights
- Headset Jack
- Erase Button
(CVR)
VHF Communications
HF Communication
- the system provides short range voice communications in the frequency range of 188.000 to 136.975 MHz.
- provides long - range of voice communications in the frequency range of 2 to 30 MHz.
CVR continuously records:
- Radio Communications
- Flight Crew Conversation
- Aural warnings; and
- General sounds from the flight compartment
COMMUNICATION SYSTEM
- a communications system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, and data terminal equipment (DTE) usually capable of interconnection and inter operation to form an integrated whole.
SELECTIVE - CALLING RADIO SYSTEM
SATELLITE COMMUNICATION
(SELCAL)
(SATCOM)
- SATellite COMmunications systems allows to exchange data and control devices remotely even from thousands of Km.
- signal transferring between the sender and receiver is done with the help of satellite. In this process, the signal which is basically a beam of modulated microwaves is sent towards the satellite. Then the satellite amplifies the signal and sent it back to the receiver’s antenna present on the earth’s surface.
- is a selective-calling radio system that can alert an aircraft's crew that a ground radio station wishes to communicate with the aircraft.
- SELCAL uses a ground-based encoder and radio transmitter to broadcast an audio signal that is picked up by a decoder and radio receiver on an aircraft.
- The use of SELCAL allows an aircraft crew to be notified of incoming communications even when the aircraft's radio has been muted. Thus, crew members need not devote their attention to continuous radio listening.
Two Satellites which commonly used:
SELCAL Operates:
Passive satellites: It is just a plastic balloon having a metal coated over it. This sphere reflects the coming microwave signals coming from one part of the earth to other part. This is also known as passive sphere. Our earth also has a passive satellite i.e. moon.
Active satellites: It basically does the work of amplifying the microwave signals coming. In active satellites an antenna system, transmitter, power supply and a receiver is used. These satellites are also called as transponders.
In AVIATION mainly used satellites are:
- high frequency (HF) or very high frequency (VHF) radio frequency bands used for aircraft communications.
- Iridium - Only Iridium’s global satellite communication service allows aviation users to send and receive voice, messaging and data regardless of their positions on or above the earth: air-to-land, land-to-air and air-to-air. With equipment options that are compact and simple to install, Iridium is a powerful, yet practical single satellite solution for your aviation communications needs.
- Inmarsat - the satellite communications network is the backbone for two-way voice, fax and data services for aircraft operating virtually anywhere in the world.