Summer Training at L.B.S.AAI BABATPUR Varansi

1. 1
Airports Authority of India
भारतीय विमानपत्तन प्राविकरण
Lal Bahadur Shastri International Airport
Babatpur Varanasi
A REPORT
ON
AIRPORT FACILITY FAMILIARIZATION
DURATION: 11th
June- 6thJuly, 2018
Under the guidance
Of
Mr. S.S. Yadav, AGM (Com-ops)
Submitted by
Group – D

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GROUP – D
Name Of Trainees
S.No. Name College Name
1. Shivpujan Gupta
(Monitor)
Mahamaya Polytechnic of Information
Technology,
Chandauli
2. Awanish Kumar
Vishwakarma
(B.Tech)
UNS Institute of Engineering and Technology
VBS Purvanchal University,
Jaunpur
3. Ashay Rai Banaras Institute of Polytechnic and
Engineering,
Varanasi
4. Shubham Kumar Sonkar Mahamaya Polytechnic of Information
Technology,
Chandauli
5. Shubham Kumar Tiwari
(B.Tech)
Jaypee Institute of Information Technology,
Noida
6. Vaibhav Kishan
(B.Tech)
Galgotias College of Engineering and
Technology, Greater Noida
7. Sonu Singh Yadav Mahamaya Polytechnic of Information
Technology,
Chandauli
8. Vikas Sahani Mahamaya Polytechnic of Information
Technology,
Chandauli
9. Vinay Pal Mahamaya Polytechnic of Information
Technology,
Chandauli
10. Alok Kumar Banaras Institute of Polytechnic and
Engineering,
Varanasi
11. Satyajeet Kumar Banaras Institute of Polytechnic and
Engineering,
Varanasi
12. Namrata Yadav Government Polytechnic,
Jaunpur

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Contents
S. NO. Topic Page No.
1.
AUTOMATIC MESSAGE SWITCHING
SYSTEM(AMSS) 4
2. AIR TRAFFIC MANAGEMENT
&
AIRPORT SYSTEM
13
3. RADAR & Automation 19
4. NAVIGATIONAL AIDS 25
5. EQUIPMENT ROOM 37

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CHAPTER 1
AUTOMATIC MESSAGE SWITCHING SYSTEM(AMSS)
Associated Officer: MR. S.L.P.R. Maurya (AGM-CNS)
1.1 INTRODUCTION
AFTN (Aeronautical Fixed Telecommunication Network) is a worldwide system of aeronautical
fixed circuits provided for the exchange of messages and or digital data between aeronautical fixed
stations. These messages are related primarily to the safety of air navigation and regular, efficient and
economic operation of air services. Some circuits of the AFTN are within one state and others are
provided as international circuits. In the AFTN, messages are required to be transmitted to a number of
addressees. It is impracticable for each aeronautical fixed station to be connected physically to all other
such stations. Therefore, the AFTN is organized around a system of relay stations, wherein messages
and/or digital data are transmitted forward circuit by circuit by successive communication centers until
they reach their destinations.
ECIL AMSS is a computer based AFTN, running on UNIX and Windows NT network
operating system in which different offices/sections of an airport (like AMSS Supervisor, HFRT,
Booking, ATC, METetc.) are connected through a Local Area Network (LAN). The Local Area
Networks of different airports are connected through dedicated leased lines provided by BSNL. The
system is meant for automatic exchange of message between various airports and related
establishments. It is more users friendly and faster than TUL AMSS and also incorporates additional
features like Automatic Self-Briefing System (ASBS) and X.25 high-speed data link. The ECIL
AMSS software can support up to 128 channels.
1.2 SYSTEM CONFIGURATION
The ECIL AMSS consists of following components.
1. Ethernet Switch / Hub
2. Workstations / Nodes.
3. AMSS Server (s).
4. Disk Switch.

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5. Database Server (s).
6. X.25 / Communication Server.
7. Communication Channel Multiplexer (CCM) Adaptor.
8. Line Termination Unit (LTU) Rack.
9. Patch Panel Rack.
10. Remote Printers.
11. Uninterrupted Power Supply (UPS)
1.2.1Ethernet Switch/Hub:
Ethernet Switch or Hub is a central unit through which all the servers and workstations/nodes are
interconnected by LAN cables. The advantage of using Ethernet Switch over Hub is that, the improved
client server response time can be achieved by means of bandwidth sharing when more number of
workstations is used.
1.2.2 Workstation / Node:
Each position (like Supervisor, NOTAM booking, HRFT etc) is having a personal computer referred as
Workstation or Node which consists of Main System Unit, 15” color monitor, TVSE Keyboard, two
button mouse and serial printer. The workstations are running on Windows NT Workstation 4.0
operating system. Any position wants to use ECIL AMSS must run appropriate application program
(for example supervisor.exe for supervisor position or hfrt.exefor hfrt position) on his workstation.
1.2.3 AMSS Server (s):
The AMSS servers are running on SCO UNIX 5.05 operating system. The ECIL AMSS is having two
servers; one is configured as SYSTEM A and other as SYSTEM B. At one time any one of the server
can be made Online and the other Hot Standby. This is done by running appropriate Unix Shell
Scripts (./n or ./r or . /h) in respective servers. Both of the AMSS servers are installed with Switch
Over Logic Control (SOLC) cards. Depending upon which server is online (SYS A or SYS B), both
SOLC cards provide SOLC logic to the LTU rack. This logic connects the online server to the
outgoing/incoming channel in the LTU rack. The Online and Hot Standby servers communicate health
to each other through SOLC cards. The AMSS server is installed with Stallion card as communication
controller module to serve multiple numbers of channels. Both the AMSS servers are
printed on these printers.

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1.2.4 Disk Switch:
Both the AMSS servers, System A and System B are connected to two SCSI (Small Computer
System Interface) disks in daisy chain fashion, using SCSI connectors. The SCSI disks are referred as
DISK 0 and DISK 1. Each SCSI disk and its corresponding connector are housed in a single cabinet
and as a whole referred as Disk Switch. The SCSI Disk 0 is housed in Disk Switch 01 and Disk 1 is
housed in Disk Switch 02 respectively.
Each SCSI disk is logically divided into two partitions, referred as FILE 0 & 1. Online server stores
outgoing / incoming messages on these four partitions (File 0, 1 of Disk 1 & File 0, 1 of Disk 2) in
sequence at the intervals of 30 seconds. Both the disks store data for 30 days.
1.2.5 Database Server:
The Database Server is running on Windows NT Server 4.0 operating system. The purpose of this
server is to maintain a database of transmitted/received NOTAM/MET/ATC/FIC messages for which
data have to be kept for more than 30days. In international airports where message traffic is high, more
than one-database servers are used for storage of ATC, FIC, and MET/NOTAM messages.
The RAID controller card is installed in the Database server to connect more than one SCSI
disks in an array, called Redundant Array of Inexpensive/Independent Disks (RAID). The
advantages of using RAID are manifold. If any one of the disks in the array becomes unserviceable, it
can be removed without affecting the functionality of the system. Disk mirroring is also possible if
even numbers of disks are used, to enhance data security.
1.2.6 X.25 Server:
In airports where traffic is very high it is required to send data over a high-speed line and for this
purpose X.25 server is used. This server acts as an interface between LAN of any particular airport and
X.25 line. The X.25 server is connected to X.25 line through a high-speed modem or PAD (Packet
assembler and Dissembler). The X.25 server is also running on Windows NT Server 4.0 operating
system and having additional hardware (EICON card) to incorporate X.25 communication interface.

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1.2.7 CCM Adaptors:
The CCM adaptors are used as the interface between of the Unix server and the LTU rack. It works in
coordination with Stallion card for multiplexing of messages through different channels. Each CCM
adaptor can support up to 16 numbers of channels.
1.2.8 Line Termination Unit (LTU) Rack:
The LTU rack consists of it’s own power supply modules and three types of line termination units,
LTU C, LTU B/C/M, and LTU D. The term B/C/M refers to the modes of LTU operation. All of these
LTU cards are terminated on the same back plane motherboard in the LTU rack.
• LTU B/C/M: The LTU B/C/M card is basically a communication interface card, which is
terminated on back plane motherboard by 64-pin EURO connector. The card provides
interfacing capabilities for three different interfaces namely:
a. Tele-printer Interface (B Mode).
b. Terminal Interface (C Mode).
c. Modem Interface (M Mode).
Any of the above modes can be selected, one at a time through Dipswitch selection. In B mode
LTU B/C/M does the code conversion (ASCII to Baudot and vice-versa) as well as voltage
conversion (from +/- 60 volts TP level to +/-12 volts RS 232 level and vice-versa). This unit
also provides line isolation, over voltage protection, current protection etc.
• LTU C: It is used to connect remote printers to UNIX server. Unlike LTU B/C/M, LTU C only
operates in C mode(RS 232 to RS 232 interfaces and also performs the functions of line
isolations, over voltage protection, current protection .
• LTU D: The SOLC cards of both the AMSS servers provide the SOLC logic signals to LTU-D
card. The logic level of these signals depend upon, which AMSS server is online (SYS A or
SYS B). LTU D card further extends this logic signals to all other LTU cards through back

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plane motherboard. These logic signals then connects the SYSTEM A or SYSTEM B, which
is presently online to the outgoing/incoming channels and remote printers.
• LTU Rack Power Supply: The LTU rack has four redundant power supply modules
a) +60 V DC, 6 Amps.
b) –60 V DC, 6Amps.
c) +/- 12 V DC , 5 Amps.
d) +5 V DC , 30 Amps.
Above dc supplies are required by LTU cards electronic circuitry and for voltage conversion.
Input to all the above modules is 176V - 264V, 50Hz A.C. supplied distribution box housed in
the LTU rack. The supply to AC distribution box is from AC mains.
1.2.9 Patch Panel Rack:
The Patch panel, Modems and Line Drivers are housed in this rack.
• Patch panel: The output of LTU B/C is connected to TP lines at patch panel using U LINK. Each
patch panel module is capable of connecting 16 channels. The loop back test for the system
side as well TP line side can be done by changing the position of U LINK.
• Modems: Any remote computer can be connected to the ECIL AMSS using Dial Up modems.
• Line Drivers: The line drivers are used to connect remote printers, which are far away from the
system site. Line drivers can drive the line up to a distance of 15 Kms at 300 bps, 12 Kms at
1200 bps, 8 Kms at 9600 bps, and up to a distance of 2 Kms at 19.2Kbps.
1.2.10 Remote Printers:
The ECIL AMSS is incorporated with Report Printer; Reject Printer located in supervisor position and
Drop Printers located in other positions as required. These printers are referred as Remote Printers. The
remote printers are connected to UNIX server through LTU C.

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• Report Printer: System generated Hourly, Half hourly reports and other system information are
automatically printed on this printer.
• Reject Printer: Messages rejected by the system and Channel Check and Mis-check messages are
automatically printed on this printer.
• Drop Printers: As per the requirement of the station, Drop printers can be provided to any location
through LTU C.
The address locations of these remote printers have to be defined in the data files of UNIX server.
1.2.11 Uninterrupted Power Supply (UPS):
The ECIL AMSS is equipped with a VINITEC Alpha series UPS to supply uninterrupted AC power of
high quality to the system, even when the incoming main is cut off completely. The capacity of the
UPS depends upon the load. A battery bank does the necessary storage of electric energy. The UPS
consists of following basic elements:
• Rectifier / Charger.
• Inverter.
•Battery bank
1.3. System Overview
1.3.1. IP-AMSS Overview
The IP-AMSS is a computer based system, centered on the AFTN for exchange of Aeronautical
messages by means of auto-switching for distribution of messages to its destination(s), which works on
store and forward principle. It has four major areas :
1) System : IP-AMSS is a dual architecture computer based system consists of few servers and
workstations which are linked with each other over a local area network , and subsequently connected
with other AMSS or Aviation Systems through BSNL/MTLN/Satellite/Others media to form wide area
network as well as other equipments/devices for data communication.
2) Messages : IP-AMSS is mainly for exchange of AFTN messages as defined by ICAO, but at the
same time it can handle some non-AFTN messages within local network.
3) Switching : IP-AMSS receives messages from User’s Terminal directly connected to it and also
terminals or lines or systems connected indirectly via other switch/routers/media etc., and after
analyzing store the messages as well as automatically retransmit the messages to its destination.

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During the above process, it uses switching system, which allows on demand basis the connection of
any combination of source and sink station.
4) Application Software : The IP-AMSS uses mainly four type of application –
(a) Message switching application,
(b) IP-based communication processes/application
(c) Database application and
(d) Customized User’s Frontend applications.
AFTN message validation/verification as per ICAO specified standard and action thereof, storing,
message switching, message queue management etc. etc. are taken care by IP-AMSS main switching
application. IP Communication processes are responsible for exchange of data with remote
system/terminal over standard TCP/IP protocol. Database application is mainly for parsing of ATS
messages, verification, validation and storing in database with the other services. User’s Frontend
Application to cater the customer requirement including system supervision & control, data feeding,
message monitoring, database query etc.
1.3.2. Main Advantages and Facilities
The main objective of the IP-based AMSS on Linux platform is to provide ‘store and forward’
message switching service over AFTN with the following enhanced facilities to overcome the present
challenges and to handle future data requirement:
ü Flexibility on hardware and software with COTS products and ready to support present day’s
machines as well as future platforms, i.e., supports LP64, ILP64 and
LLP64.
1. Both Hot-Standby and Cold-Standby dual architecture system with common storage system
like SAN, SAS or NAS storage system. Even, ready to work with the help of internal storage
facility without any external common storage device(s), in case of failure of SAN/SAS/NAS
services.
2. Direct communication between AMSS and other network system over IP for exchange of ITA-
2/IA-5 AFTN messages.
3. Serial RS232 communication support through ‘Print Server’ or over IP-Serial devices.
4. Maintaining same unique IP identity for online Server in dual architecture for remote network
connectivity irrespective of which server is online.
5. AMSS Server switching application on Linux platform is ready to run on 32-bit or 64-bit
(LP64/ILP64/LLP64) system with auto-compatibility design.
6. Inter/Intra IP-base communication compatibility with Automation System (Indra/Raytheon) ,
DATIS, AOCC, DVOLMET, AMSS-to-AMSS etc.
7. X.25 Communication with the help of existing EICON card or directly from AMSS Server over
IP-V.35 (X.25) converter.
8. Maximum lines support : 252 lines
9. Circuits/Line speed supports from 300 to unlimited.
10. Per Line message speed : 500 to 2000 messages per hour.
11. AFTN Messages handling capacity : max 10 lakh messages per day with storage for 30
days(Internal)
12. System activity and log storing in files
13. Backup of Messages in external hard disk
14. System Storage disk backup in external disk with current system snapshot.
15. Time synchronization through Time Server or with the pulling the Time-Stamp from
Automation Terminal (IP based).

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16. User’s Application and Database Backend Application for 32-bit /64-bit platform. Easy
installation with 64-bit support and compatibility.
17. Remote Station (RWS) Application for small Airports with two options : RWS Application as
like existing extended LAN style to receive and transmit AFTN messages through parent
AMSS station , or Portable standalone mini-AMSS with facility to handle 10-15 external like
LAN terminals, Local DATIS line, Local Automation line etc.
18. AMSS network monitoring and status display as GUI Application
1.4. System Architecture
1.4.1. IP-AMSS Architecture
IP-AMSS is designed in a multi-tier client-server model system on Linux platform to provide AFTN
message switching service.
IP-AMSS consists of 4(four) major components:
1. Core System
2. Storage System
3. Database Storage System
4. User’s Terminal
Core System :
It incorporates communication adapters, protocol/suites, routing and gateway facilities.
The core system is composed of two identical machines ( IP-AMSS main servers :
AMSS-1 & AMSS-2) which runs in an operational (Online /Active) / hot standby (Passive/Offline)
combination.
Both units monitor each other status. In case of failure of the operational unit, the hot standby unit is
activated automatically within 30-40 seconds without loss of data. Both the units have a common
storage (HDDs) and / or Own disk as Data Replicated Block Device (DRBD).
Both units are COTS product and ready to work on Linux Platform.
Storage system:
It may be any one or both of the following:
· External SAN Storage system connected with two hosts over OFC.
· Internal RAID-1 Disk as DRBD storage
Database Storage System :
It has two identical database servers with the replication of meta data for storing of specified type of
messages related with flight plan & associated messages, NOTAM messages, MET messages etc.
OS : Microsoft Windows Server ( 2003/2008)
DB : Microsoft SQL Server 2003/2005
Users’ Terminal :
It is the interface between user and the system with capability for administration and monitoring
facilities for all system components, networks and data as well as exchange of data as per requirement
of users by means of different type of frontend application software.
OS : Microsoft Windows XP / Windows 8x / Windows 10
1.4.2. Core System Logical Components
The main logical components of the core system are:

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1. The Server Processing component
2. It is the kernel class of the application, and which routes the messages after validation to the
correct interface component.
3. The Client-Server Interface components
4. It handles the communication with the local terminals and existing X.25/TCP-IP
communication servers.
5. The Broadcast Interface component
6. It handles the interface with all local terminals for time synchronization w.r.t. server.
7. The IP-Link Interface components
8. It handles the interface with all external/remote device/network over standard IP.

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CHAPTER 2
AIRPORT TERMINAL MANAGEMENT
&
AIRPORT SYSTEM
Associated Officer: MR. S.N. SINGH (AGM-CNS)
Introduction to terminal building: the terminal building of Varanasi Airport is broadly divided into two
parts:
1: International departure and arrival section
2: Domestic departure and arrival section
2.1. INTERNATIONAL DEPARTURE:
1. The passenger boarding on international aircraft enter through the separate departure gate of the
international departure building.
2. The baggage’s of passenger are checked by X-Bis machine.
3. Weight of the baggage is measured. The allowed weight is
4. The ticket & passport are checked by the aircraft agency at their respective counter& immigration
counter.
5. Custom checking is done.
6. DFMD checking & small baggage checking by X-Bis before entering the security holding area.
7. If suspected physical checking is done (separate cabin is provided for Ladies.
8. Security holding area: the passengers are made to remain in the SHA.No passenger is allowed to go
back to the terminal building after entering this area except some guenine cases & if he does so he is
again checked serially through above procedure.
9. From security hold area the passenger is allowed to board in the aircraft.
Before boarding just into aircraft, a final boarding checking is done.
2.2. INTERNATIONAL ARRIVAL:

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1. On arrival passengers are made to go through custom checking
2. They are checked by walk through metal detector
3. Their baggage & luggage are brought from aircraft to X-Bis machine through conveyor belt and is
checked . If suspected then physical checking is done.
4. After clearance and getting baggage’s and luggage, passengers are made to go outside through the
city side door (arrival gate).
NOTE: Due to only one international aircraft the same door is used as arrival gate and departure gate
in Varanasi airport.
2.3. DOMESTIC ARRIVAL AND DEPARTURE
2.3.1. DEPARTURE:
1. The boarding passenger with their baggages are made to enter through departure gate .
2. DFMD & HHMD checking is done.
3. Passenger goes to respective aircraft agency counter for ticket verification.
4. Simultaneously baggage checking is done by X-Bis machine.
5. After ticket & baggage checking passenger wait in the passengers lounge for the announcement of
their respective flight.
6. On announcement of security check passengers proceed towards security hold area. Before entering
SHA once again passenger is passed through DFMD & his baggage is checked by X-Bis machine.
7. No passenger is allowed to go back to the terminal building after entering this area except some
guanine cases & if he does so he is again checked serially through above procedure.
2.3.2. ARRIVAL:
The procedure is same as international arrival except that no X-Bis DFMD & custom checking is done.
NOTE: In Varanasi airport there are three domestic aircraft agencies
In operation (Indian Airlines, Jet- Airways, SPICE JET) 20 kg is allowed without any extra charge per
passenger.
2.4. FLIGHT INFORMATION DISPLAY SYSTEM (FIDS)
The flight information display system displays the flight status to the passengers. It consists of split flap
boards that display flight code, flight number, flight status time, gate number and indicators. The airline
personnel update the information displayed on FIDS.

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FIDS may consist of large display board, video display monitors, video projectors etc. these are
logically connected to receive flight information from central operating console (COC).
In Varanasi airport there are 42 FIDS (SOLARI)
2.5 SECURITY EQUIPMENTS
2.5.1. EXPLOSIVE TRACE DETECTORS (ETD)
The IONSCAN 500DT is a powerful analytical tool that can simultaneously detect and accurately
identify. Trace residues of a wide variety of narcotic and explosive substances by using Ion mobility
spectrometer (IMS) technology.
Specifications:
Technology Dual Ion mobility spectrometer (IMS) technology.
Operating modes Explosives /narcotic simultaneous, Explosives only, Narcotic only
Analysis time 5-8 seconds
Warm-up time 30 minutes
Input voltage 95-265VAC
Sensitivity explosives picogram range, narcotics sub nanogram range
In Varanasi airport there are 4 IONSCAN500DT ETDs .Two at check-in area, one at domestic SHA,
one at international SHA.
2.5.2. X-RAY MACHINE
X-BIS:
The objects to be inspected are transported through the unit inspection tunnel via a conveyor belt at a
constant speed.
When an object enters the tunnel, it is detected by a light barrier system. Simultaneously the x-ray
generator is switched on by means of a collimator an extremely thin fan shaped x-ray beam is
generated which penetrates the object in the course of the inspection. The beam is partially absorbed
by the object and finally strikes a detector line.
Technical specifications
X-ray frequency band: 23 kHz-29 kHz
Resolution: standard 0.1mm

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Penetration (steel): standard 27mm
X-ray dose: 0.07mren
Anode voltage: 140KV
Grey levels stored: 4096
X-ray converter: L shaped detector line
Power consumption: 0.8 KVA
In Varanasi airport there are 9 X-BIS machines.
Sl.no Name Of The Equipment Terminal Total Quantity
1 X-BIS 145180 cargo 01
2 X-BIS HS9075 Entry gate 01
3 X-BIS HS100100V Check-in 02
4 X-BIS HS6040i International SHA 02
5 X-BIS HS6040i domestic SHA 03
2.5.3. DFMD (METOR 200)
METOR 200 metal detector is designed to activate an alarm when the signal caused by a metal object
taken through the detector exceeds the present alarm level. Due to the multizone principle used in
metor 200 it discriminates reliably weapons from innocuous item and indicates the height where a
weapon was taken through the gate.
In Varanasi airport there are 6 DFMD (METOR 200)

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Sl no Name Of The Equipment Terminal Total Quantity
1 DFMD (METOR 200) Entry gate 01
2 DFMD (METOR 200) International SHA 02
3 DFMD (METOR 200) domestic SHA 03
In Varanasi airport there are 29 HHMDs which are maintained by CISF
Sl no Name Of The
Equipment
Terminal Total Quantity
1 HHMD METOR28 WITH CISF 17
2 HHMDPD140 WITH CISF 12
2.5.4. CLOSED CIRCUIT TELEVISION (CCTV)
For surveillance there are CCTV installations at different vital positions. It covers the entire
passengers’ route. The components of the CCTV system are
1. Camera
2. Monitor
3. CCTV rack
Camera: In Varanasi there are 69 CCTV (INFINOVA) cameras (56 installed) .There are two types of
cameras.
1. fixed camera (make Philips)
2. p/t/z camera (pan/tilt/zoom)
CCTV rack consists of
1. Matrix switcher
2. Digital recorder cum multiplexer
3. Data archiving and tape drive (DAT Device for back up)

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4. Keyboard for controlling
2.6. PUBLIC ADDRESS SYSTEM
The Public address system gives the flight status and other related information to the passengers
through announcements.
The PA system for direct announcement consists of
1. Announcement console which includes MIC, limiter compressor
2. Two dual 35 Bose amplifier racks
3. Noise sensing microphones
4. Sound column loud speakers
5. Ceiling ring loud speakers
6. Indoor loud speakers
The announcement console is located in the announcer’s room. The amplifier racks are located in the
control room. The speakers are used to achieve uniform sound distribution of the music and
announcement signal through the airport premises. The noise sensing microphones are mounted to pick
up the average noise level in respective zones which ensure the signal level is 6db above the noise
level. The signal is then fed to AVR modules which control the overall gain of the signal. Normally the
soft music is relayed overall loudspeakers in the zones. Chime signal tone precedes the announcement
signal.
Other existing security equipments at Varanasi airport:
 Night vision goggles with CISF

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CHAPTER 3
RADAR AND AUTOMATION SYSTEM
Associate Officer: Mr. Vinod Kumar, (Joint GM – CNS)
Mr. Shivbahadur Singh
3.1 RADAR PRINCIPLES
The Radar operates on the principle that energy emitted from the source travels at a uniform speed may
get scattered or reflected by the obstructing surfaces or objects which lie in the path of travelling
energy. A portion of transmitted energy is reflected back to the source. These reflections are the
“echoes” which resembles the transmitted energy. These echoes are then processed and the targets or
obstructing surfaces are identified. The target range is measured by the elapsed time from the
transmission to the reception, and the azimuth of the target is measured from the reflections received at
the time of beam direction.
3.2 PRIMARY RADAR
Primary Radar consists of a transmitter and a receiver each connected to a directional antenna. The
Transmitter is capable of sending out microwave power through the antenna. The receiving antenna
collects as much energy as possible from the echoes reflected in its direction by targets, and is then
processed and displayed this information in a suitable way. The receiving antenna is very often the
same as transmitting antenna. This is possible through a kind of Time Division Multiplexing (TDM)
arrangement, since the radio energy is very often sent out in the form of train of pulses.
Advantages of a Primary radar
a. It works independently thus active cooperation of target is not necessary.
b. It is not likely to get saturated
c. Electronic systems are much simpler. It requires one set of transmitter & receiver.

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Disadvantages of Primary Radar
Since the energy has to travel the two-way distance, the transmitter power should be too high
compared to the Secondary Radar for the same distance, antenna gain, and same receiver sensitivity.
a. The Receiver sensitivity should be kept too high, as it receives very less echo energy
returns.
b. As the transmitter and receiver frequency are same, the alignment between these
sections is critical for proper detection.
c. The blip strength is directly proportional to the range, size and material of the target.
d. It will not provide the Altitude information.
3.3 SECONDARY RADAR
A Secondary Surveillance Radar (SSR) consists of two principal components namely the
INTERROGATOR, a ground based system and the TRANSPONDER, which is carried by the target.
The Interrogator interrogates transponder-equipped aircrafts, and receives the coded replies back from
the transponder. The replies are processed into a digital report message. The range and azimuth of the
target is measured by the method as stated earlier, along with the added information namely;
surveillance of the target & datalink with the target is also available. It is this information, which is of
immense help for air-traffic control purposes.
Advantages
a. Selective addressing of aircrafts is possible.
b. Altitude information of the aircrafts is made available.
c. For a given range, the transmitter (Interrogator) power required is less compared to
Primary radar, since the signal has to travel one-way distance only from the Interrogator
to the target transponder.
d. The received signal is not echoes, but it is from onboard transmitter (Transponder) in
the aircraft. Hence, the receiver sensitivity need not be very high.
e. As Interrogator and Transponder transmit frequencies are different, the ground clutter
problems are eliminated.
f. Solid-state technologies are used and no need for very high voltage.

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Disadvantages
a. Active cooperation of the target is very much required.
b. Like DME, saturation of targets is a limiting factor.
c. System operation depends upon aircraft equipment. (Transponder serviceability).
3.4 RADAR OPERATIONS AND MODES
Manufacturer: Westinghouse Electric Corp
Type of radar: Monopulse surveillance secondary radar (MSSR)
Transmitting frequency: 1030MHz
Receiving frequency: 1090MHz
Intermediate frequency: 60 MHz
Maximum Aircraft handling capacity: 700
Range: 255 Nm
Azimuth accuracy: 0.068 degrees
Beam width: 2.4 degrees at 3 db point
Scan rates: 5 to 15 rpm (12 RPM at Varanasi)
P R F: 126
Co-ordinates:25 27 34N
082 51 47E
Commissioned on 02-07-2003.
Functional characteristics:
1. Transmit Power: Primary-800Watts; Auxiliary- 3200Watts
2. Receive Power: 60dB dynamic operating range -95dBm sensitivity
External power requirements: Interrogator- 3 phase; 120/208V AC L-L 60Hz; 5Amps/phase.
We get the following information from the MSSR -
1. Range
2. Azimuth
3. Identity
4. Altitude

22. 22
Type of interrogations-
1. Mode 3/A & Mode C: It is also called ATCRBS mode
3/A interrogator:
Interrogation: identity request
For this we can use two pulses P1 & P3. Width of pulse P1 & P3 are 0.8 micro sec. Pulse interval
between P1 & P3 is 8 micro sec. Here also a third pulse is used called P2 known as side lobe
suppression pulse. P2 pulse is transmitted after 2 micro sec. from the P1 pulse is transmitted.
P1 & P3 pulses are transmitted through the main beam antenna while the P2 pulse is transmitted
through a separate omni directional antenna. If P2 > P1 then transponder will not reply.
Mode-C:
Interrogation: Altitude request
For this we can use two pulses P1 & P3. Width of pulse P1 & P3 is 0.8 micro sec. Pulse interval
between P1 & P3 is 21 micro sec. Here also a third pulse is used called P2 known as side lobe
suppression pulse. P2 pulse is transmitted after 2 micro sec. from the P1 pulse is transmitted.
ATCRBS Reply: The interrogator interfaces with the data processing system and the radar. The
interrogator operates with the radar during independent air traffic control radar beacon system
(ATCRBS) mode. The interrogator interrupts interrogation commands received from the DPS and sent
RF transmit signals to the antennas. The interrogation replies are received from the antenna and
processed in the receiver/RFTTG and signal processor. The interrogator sends the reply data to the
DPS for further processing.
An ATCBRS consist of a pulse train that contains 3-15 pulses. ATCBRS reply format contains an
initial bracket pulse, F1 followed by 12 positions (which may or may not contain pulses) and than a
final bracket pulse, F2.
The location of the pulse positions are based on their relationship to the F1 bracket pulse. The pulse
positions are separated by 1.45 micro sec. and each is 0.45 micro sec. wide. The 12 pulse positions are
divided among 4 octal digits A-D and each pulse position is weighted 1, 2 or 4.
3. Mode S: It has two basic functions: locate and identify aircraft and test for faults. The unit used by
the interrogator to perform these functions is transmitter, receiver/ RF test target generator (RFTTG),
signal processor power distribution circuit.

23. 23
4. Mode 4: Military Mode
NAME OF EQUIPMENT USED:
1. Interrogators: No. of interrogators racks is 2 and each rack consists of:
1. Transmitter &Receiver Section
a) Local oscillator
b) Modulator driver
c) Primary power amplifier
d) Auxiliary power amplifier
e) Level control
f) Diplexer
g) Directional coupler
Receiver Section
a) Diplexer
b) Hybrid ring
c) Mixer
d) IF amplifier
e) Video Processor and monitoring unit

24. 24
2. DPS (Data Processing System)
3. Fiber distribution frame
4. Antenna control unit
5. Air dryer
6. AC distribution: Mains supply is 230V ac. It is converted into 110V ac by using transformer.
7. Two UPS: Each 60KVA connected in parallel.
8. Two Battery Bank: Each 433V
Different DC regulated voltage used by different modules:
+15V, -15V, +5V, +36V, +52V, +24V
9. MMI (Man Machine Interface)

25. 25
CHAPTER 4
NAVIGATIONAL AIDS
Associated Officer: Mr. R.K. Srivastava Jt. GM( CNS)
Mr. Ashok kumar, JE(CNS)
4.1. NON-DIRECTIONAL BEACON(NDB)
4.1.1. MAKE: SOUTHERN AVIONICS COMPANY (SAC)
4.1.2. INTRODUCTION: It is an AM transmitter with an adjustable output power up to 100 watts
using switching technology in the power amplifiers and modulator/regulator modules resulting in a
highly efficient system in a small package.
4.1.3. RADIATED POWER: 100W
4.1.4. MODULATION SCHEME: Amplitude Modulation
4.1.5. FREQUENCY USED: 222 KHz (Varanasi)
4.1.6. IDENTIFICATION CODE: BN
4.1.7. RANGE: 200NM
4.1.8. MODULATION DEPTH: 80%
4.1.9. CARDS IN EXCITER MODULE:
(i) Synthesizer (190-535 kHz): The RF signal is generated on the KWOSYN PWB by VCO.
(ii) Tone Key (1020Hz or 400 Hz): Two separate audio tones ,400Hz and 1020 Hz are generated on the
TONE KEY BOARD PWB. One of the tones is selected and fed trough a gate controlled by the keyer.
(iii) Programmable Morse code keyer.
(iv) A Monitor circuit: It monitors the forward power, reflected power and percent modulation.
(v) Code shift register.
4.1.10. POWER AMPLIFIER SECTION:
(i) Filter: The filter module covers 190-535 KHz in 5 bands. Bands are selected with jumpers.
(ii) SPA (Switching Power Amplifier): The half-bridge switching power amplifier amplifies the RF
Drive signal and delivers an amplitude modulated signal with a power level up to 400 watts peak to the
filter module.
(iii) Switch modulator/regulator

26. 26
(iv) Power Supply: Power for the transmitter can be supplied from 115/230 VAC, 24 VDC(Optional)
,or both automatic change over to batteries (optional) when AC power is lost.
4.1.11. ANTENNA COUPLER: It couples the 50 ohm output of the transmitter to a "T" Antenna. It
consists of an impedance Transformer, a large tapped coil with rotate able shorted ring. The shorted
ring is driven by a motor that is controlled by the Auto tune motor Drive PWB in the coupler a large
tapped coil Meter.
4.1.12. ANTENNA USED: T-type Antenna
4.2 DISTANCE MEASURING EQUIPMENT (DME) (High Power)
4.2.1. MAKE: AIRSYS ATM-THALES DME 435
4.2.2. INTRODUCTION: Distance Measuring Equipment is a vital navigation Aid, which provides a
pilot with visual information regarding his position (distance) relative to the ground based DME
station.
4.2.2. FREQUENCY RANGE: 960 MHz to 1215MHz.
4.2.3. CHANNEL: 86X
4.2.4. IDENT: BBN
4.2.5. TRANSMISSION RATE: 800 - 4800 PPS.
4.2.6. AIRCRAFT HANDLING CAPACITY: 200
4.2.7. RANGE: 200NM
4.2.8. EFFICIENCY: 70 % (minimum)
4.2.9. POWER SUPPLY: 194/260 VAC; 48 VDC.
4.2.10. DIFFERENT MODULES:
(i) Two 1 K watt Transmitter (Main & Stand by)
(ii) Monitor card
(iii) Receiver
(iv)Signal Processor (DPR)
(v) Demodulator (DMD)
(vi)Power Supply Card
4.2.11. MAINTAINENANCE SCHEDULE:
DAILY PARAMETERS:

27. 27
(1) DC Supply.
(2) AC Supply.
(3) System Delay.
(4) Pulse pair Spacing.
(5) Reply Efficiency.
(6) Transmission Rate.
(7) Peak Power Output.
(8) Minimum Reply Rate.
(9) Max. Reply Rate.
(10) Transmitting Frequency.
4.3. INSTRUMENT LANDING SYSTEM
4.3.1. INTRODUCTION: A complete ILS comprises a localizer system, producing a radio course to
furnish lateral guidance to the airport runway and a glide path system, producing a radio course to
furnish vertical guidance down to the correct descent angle on the runway.
4.3.2. LOCALIZER
4.3.2.1. LOCALIZER DESCRIPTION: The antenna array of the ILS localizer transmitter is located on
the extension of the centerline of the instrument runway of an airfield, but is located far enough from
the stop end of the runway to prevent it being a collision hazard. The localizer antenna radiates a field
pattern directed along the centerline of runway towards the middle and outer marker. The antenna also
furnish information outside front course area in the form of full fly left or full fly right
indication(clearance).
All localizer installations transmit Station identification in Morse code at periodic interval. This
is a 1020Hz tone that is keyed to form the basic station identification.
The localizer is designed to provide a signal at a minimum distance of 25 nautical miles within +/- 10
& +/-35 degrees from the front course line.
4.3.2.3. CATEGORY: Category-I Localizer 27
4.3.2.4. MANUFACTURE: NORMAC 7013, Norway.
4.3.2.5. POWER SUPPLY: Two SMPS
4.3.2.6. POWER SUPPLY UNIT: Two parallel Modules
4.3.2.7. OSCILLATOR: 1. Two parallel crystal oscillator (RF)
2. Two parallel crystal oscillator (LF)

28. 28
4.3.2.8. FREQUENCY: RF- 109.9 MHz
4.3.2.9. BASE BAND SIGNAL: 90Hz; 150Hz
4.3.2.10. IDENTIFICATION SIGNAL: 1020 Hz
4.3.2.11. STATION CODE: IVNS
4.3.2.12. TRANSMITTER: No. of Transmitter: 4 One for course and another for clearance. Course and
Clearance contain two transmitters respectively.
4.3.2.13. CLEARANCE USED: Two Frequency clearances.
4.3.2.14. ADU: 4 signals (CSB & SBO for both course and clearance) coming from ILS equipment
room are divided as per the ICAO rules and specification.
4.3.2.15. ANTENNA: Signals from ADU are fed into 12 numbers of log periodic antenna for the
desired pattern.
4.3.2.16. MONITOR COMBINER UNIT (MCU): Signals from the pickup coils of the different
antennas are picked up, combined and sent to front end monitor card.
Front end monitor card: CSB & SBO for both course and clearance and near field signals are fed into
this card.
Monitor card: Multiplexing and digitalization takes place in this card.
4.3.2.17. MONITOR PARAMETERS: RF level: 3 volts
SDM : 40%
DDM : 0%
DS : 15.5%
4.3.2.18. DATA TRANSMISSION MEDIUM: 2 wire line 600 ohm.
4.3.2.19. DATA MODULATION: FSK
4.3.2.20. POWER SUPPLY:
Input Voltage: 230V +15%/-20%
Output voltage: 27.6V
Output current: 20A
ILS Cabinet:
Input Voltage: 22-28V DC
Current consumption: 8A- 14A
Stand-by battery: 24V DC nominal

29. 29
4.3.2.21. MAINTENANCE SCHEDULE DAILY:
Temp: 22º C ± 2º
Main power: 220V ± 10%
Main frequency: 50Hz±10%
Battery: 23-28V
Monitor Delay: 6 secs
PS1: 26.8V
PS2: 26.8V
4.3.3. GLIDE PATH
The NM7000 series Glide path comprises the following units
1. Glide path Cabinet
2. Power Supply
3. Remote Control
4. RMM (Remote Maintenance Monitoring) System
The Glide path cabinet comprises:
1. Dual transmitter/modulators
2. Dual monitors in "2 out of 2" voting
3. Priority and change-over system with local control panel
4. Remote monitoring system with local display and RS-232 ports for local and remote PC
connections.
The power supply is a separate, wall mounted unit. Back-up batteries are float charged and
connected to the GP cabinet.
The Remote-Control unit is intended for installation in the tower or a technical room to give
remote control and status indication. An optional Remote Slave panel can be used if control and status
indication is required in additional positions.
The RMM system comprises the built-in RMS system in the GP cabinet, and a data program running
on a standard PC can be connected directly to the cabinet, or by modems through leased or switched
telephone lines.
4.3.3.1. MANUFACTURE: NORMAC 7013, Norway.
4.3.3.2. POWER SUPPLY: Two SMPS
4.3.3.3. POWER SUPPLY UNIT: Two parallel Modules

30. 30
4.3.3.4. OSCILLATOR: 1. Two parallel crystal oscillator (RF)
2. Two parallel crystal oscillator (LF)
4.3.3.5. FREQUENCY: RF- 329.7 MHz
4.3.3.6. BASE BAND SIGNAL: 90Hz; 150Hz;
4.3.3.7. IDENTIFICATION SIGNAL: 1020 Hz
4.3.3.8. STATION CODE: IVNS
4.3.3.9. TRANSMITTER: No. of Transmitters: 4 One for course and another for clearance. Course and
Clearance contain two transmitters respectively.
Clearance Used: Two Frequency clearance.
4.3.3.10. ANTENNA
Glide path Antenna:
Antenna used: M-array antenna. The antenna system is comprised of the following:
1. Three antenna elements
2. An antenna mast (equipped with an obstruction light)
3. A distribution network and three antennas cables.
4. A monitor system including network cables and a near-field monitor antenna.
4.3.3.11. MONITOR PARAMETERS:
1. CLR: SDM, DDM, RF.
2. CL: SDM, DDM, RF.
3. DS
4. NF
4.3.3.12. PERIPHERAL UNIT:
1. M-array distribution network
2. M-array monitor network
4.3.3.13. ANTENNA ELEMENT:
1. The radiating element is a stacked dipole antenna with reflector housed in a glass radome for
weather protection.
2. The gain of the antenna element is 12dB
Distribution circuit:

31. 31
1. The signals from the main transmitter (CSB and SBO) and the clearance transmitter signals are
routed to antenna elements via hybrids, adjustable power divider and adjustable phasors. These
components are connected by coaxial cables.
4.3.3.14. MONITOR CIRCUIT: The monitor circuit consists of
1. Pick up couplers in each antenna element.
2. Three monitor cables
3. Monitor network
4. Near field monitor antenna and cable
Integral Monitoring:
The signals from the pick -up couplers which are proportional to the radiated signals from the
antenna elements are fed through the equal length monitor cables to the monitor network.
Near-field monitoring:
The near field monitor comprises a receiving antenna mounted on a mast about 80 meters in
front of the M array antenna system and a coaxial cable sending the received signal to near field
monitor channel.
The monitor antenna is a half wave dipole fitted with a reflector; it is protected against the
weather by the fact that all the conductors are embedded in fiber glass reinforced polyester. The
monitor mast which is 5.5m high is embedded into a concrete block foundation.
For 3º glide angle the distance is approx. 83m and the height of the near field antenna should be
approx. 4.3m.
4.4 DME with GLIDE PATH (Low Power)
4.4.1. MAKE: THALES 415
4.4.2. INTRODUCTION: Distance Measuring Equipment is a vital navigation Aid, which provides a
pilot with visual information regarding his position (distance) relative to the ground based DME
station.
4.4.3. TRANSMITTING SECTION FREQUENCY RANGE: 960 to 1215 MHz. (Freq. used in
Varanasi is 997 MHz.)
4.4.4 OSCILLATION TYPE: Crystal Controlled Oscillator
4.4.5. PEAK POWER OUTPUT: 100W peak
4.4.6. OUTPUT IMPEDANCE: 50 ohms

32. 32
4.4.7. FREQ. STABILITY: ±0.002% or less.
4.4.8. NUMBER OF PULSES: More than 700PPS, less than 2,700±90 PPS.
4.4.9. RECEIVING SECTION: FREQUENCY RANGE: 1025 to 1150 MHz. (Freq. used in Varanasi
1060 MHz)
4.4.10. IF FREQUENCY: 63 MHz.
4.4.11. Pulse Priority Order:
1. Identification pulse.
2. Reply Pulse
3. Squitter Pulse.
4.4.12. POWER SOURCE: AC: 230+ 10%-15%, 50Hz∓3Hz
4.4.13. Current Drain: 20 Amps. (Max.)
4.4.14. ANTENNA:
Frequency: 960-1215 MHz
Polarization: Vertical
Impedance: 50 ohms
VSWR: 2:1 Max.
Power handling Capability: 3 KW Peak.
4.4.15. DME consists of the following:
1. Transponder----------QTY.2
2. Control Monitor-------QTY1
3. Antenna change over----QTY1
4. Power Supply --------QTY1
5. Cabinet Rack---------QTY1
4.4.15.1. TRANSPONDER:
The transponder consists of the following units:
1. Pre-selector
2. Mixer Preamplifier
3. IF video unit
4. Decoder Coder unit
5. Signal Processor Unit
6. Video control unit
7. RF unit

33. 33
Note: Of the units 4, 5, 6 are the plug units.
4.4.15.2. CONTROL MONITOR:
The control monitor consists of the following units
(a) Monitor Unit (b) Test Unit (c) Control unit (d) L/C Unit
The monitor unit monitors the following six parameters:
1. Reply delay time (system delay)
2. Reply efficiency (RCV SENS)
3. Peak Power Output (Peak Power)
4. Pulse Pair Spacing (Pulse Space)
5. Identification Code (ID)
6. Number of transmitting output pulses (Pulse Count)
Control Unit Function:
1. Transponder starts and stops.
2. Transponder selection
3. Automatic transfer.
4. Monitoring operating conditions. It monitored following conditions
(a) T/R No. 1 ON/OFF.
(b) T/R No.2 ON/OFF.
(c) TRANSFER
(d) SHUTDOWN
(e) REMOTE/LOCAL
4.4.15.3. POWER SUPPLY: The Power supply consists of the + 48 V power supplies (rectifier) and
+5V, +15V, -15 V, +24V, +48V power supplies, an alarm unit and a monitor unit. This panel is
provided by 230 VAC commercial power supply.
4.4.15.4. ANTENNA: It consists of a master antenna and two monitor antennas and has a cylindrical
form of approx 2.2 meters in length and 160 millimeters in diameter. The radiating elements are
protected by an epoxy glass cylinder designed for a minimum power loss.
4.4.15.5. ANTENNA CHANGE OVER: Its major function is the changeover between the transponder
No.1 and No.2, antenna and dummy load according to control signal from the control monitor

34. 34
4.5 DOPPLER-VERY HIGH FREQUENCY (VHF) OMNIDIRECTIONAL
RADIO RANGE (DVOR)
4.5.1. MAKE: GCEL-755
4.5.2. INTRODUCTION:
The main purpose of the VOR is to provide the navigational signals for an aircraft receiver, which will
allow the pilot to determine the bearing of the aircraft to a VOR facility.
VOR’s use as a navigational aid is based on the principle of Rho-Theta Navigation System. The Very
High Frequency Omni Range (VOR) and DME constitute the basic components of the Rho-Theta
Navigation System. While the VOR provides azimuth information (Theta) to the pilot, the DME
provides the distance information (Rho) so that the pilot receives a continuous navigational fix relative
to a known ground location.
4.5.3. ANTENNA TYPE: ALFORD LOOP ANTENNA
4.5.4. FREQUENCY RANGE: 108-118 MHz (in Varanasi Airport 113.9 MHz)
4.5.6. IMPEDANCE OF ANTENNA: 50 Ω
4.5.7. POLARIZATION: OMNI-DIRECTIONAL HORIZONTAL
4.5.8 DIAMETER OF COUNTERPOISE: 26 m
4.5.9 DIAMETER OF SIDEBAND ANTENNA CIRCLE: 13.5 m
4.5.10. REFERENCE SIGNAL: 30 Hz, Amplitude Modulated having its phase constant.
4.5.11. VARIABLE SIGNAL: 30 Hz, Frequency Modulated having its phase is related to azimuth.
4.5.12. The variable phase signal is obtained from the 9960 Hz frequency modulation sub carrier which
amplitude modulates the carrier.
4.5.13. NO. OF SIDEBAND ANTENNAS: 48
4.5.14. FREQUENCY OF BLENDING SIGNAL: 720 Hz
4.5.15. IDENT: BBN
4.5.16. TRANSMITTER SECTION
The transmitter is divided in to various blocks namely:
(a) Carrier generation and modulation sub system
(b) Side band generation sub system
(c) Timing sequence generation sub system
(d) Reference phase generation sub system
(e) Side band Amplifier Modulator and sub system
(f) Side band Antenna commutating sub system

35. 35
4.5.17.OPERATING PRINCIPLES:
Operation of the DVOR is based on the phase difference between two 30 Hz signals modulated on the
carrier, called the reference phase and the variable phase. The reference phase signal is obtained by
amplitude modulating the carrier with a 30 Hz sine wave signal. This amplitude modulated signal is
radiated Omni- directional in the horizontal plane by the central, carrier antenna. The radiation pattern
is a circle, and produces in the aircraft receiver a 30 Hz signal with a phase independent of azimuth.
4.5.18. TRANSMITTING ANTENNA SYSTEM:
The DVOR antenna system consists of a single carrier antenna assembly at the center of counterpoise,
and 48 sideband antenna assemblies spaced
equally in a 44 foot diameter circle concentric with the carrier antenna assembly. All antennas are
enclosed in small, weatherproof, fiberglass radomes.
4.5.19. CARRIER ANTENNA:
Carrier Antenna is a single Alford loop on a support plate. The antenna is supported above
the counterpoise by a metal pedestal. The antenna is electrically tuned to the station
frequency by means of a single, high voltage, glass capacitor. This antenna is designed to
function with collocated distance measuring equipment (DME) system. When required, a
metal pipe passes through the center of the antenna. The pipe serves as a conduit for feed
lines and cables to a DME antenna and obstruction lights.
4.5.20. SIDEBAND ANTENNA: Each sideband antenna is an Alford loop, similar to carrier antenna
but without the large hole in the support plate. This antenna is electrically tuned to the station
frequency by means of single, high voltage, glass capacitor. The antennas are mounted independently
on individual support plates, supported above the counterpoise by metal pedestals equal in height to the
carrier antenna.
4.5.21. FIELD MONITOR ANTENNA: There is one field monitor antenna in each DVOR system. A
single dipole antenna and dual detectors are used in each DVOR system.
4.5.22. COUNTERPOISE: The counterpoise is a circular, metallic support structure upon which the
transmitting antenna system is installed. The counterpoise typically is between 60 and 120 feet in
diameter, 8 to 12 feet above ground level. It can be aluminium or galvanized steel and is assembled of
segments bolted together.
4.5.23. EQUIPMENT SPECIFICATION DATA
TRANSMITTER:
Input Power Requirements: 230 VAC (+/- 15%),47 to 400 Hz ,single phased ,or 48VDC.Four
12 volt, sealed, lead-acid batteries(65 amp/hour)in series will provide approximately 2.5 hours of
battery operation.
Carrier frequency range & spacing: 108 to 118 MHz. with 50 kHz channel.
Carrier Frequency Tolerance: +/- 0.0005 %( 5PPM)
Carrier Output Power: Transmitter output power adjustable from 50 to 100 watts in 1 watt increments.
Effective Radiated Power: 23dBW minimum
Reference Phase signal (30Hz AM)
Frequency: 30Hz (+/-) 0.01%
Modulation Depth: 28 to 32% digitally controlled

36. 36
Variable Phase signal (30 Hz FM)
Frequency: 30Hz (+/-) 0.01%
Sub-Carrier Signal Center frequency: 9960 Hz (+/-)1%
Deviation ratio: 16(+/-) 1 at 115 MHz
Modulation Depth: 28 to 32% digitally controlled
Identification Signal:
Frequency: 1020Hz (+/-) 10Hz
Modulation depth: 5 to 20 % adjustable
Code: 2, 3, 4 letters in Morse code
Rate: 8 words per minute
Repetition: 4times/30 seconds; 3 times with co-located DME
Antenna System
Type: Alford loop with associated pedestal and fiberglass radome
Frequency Range: 108 to 118 MHz, fine tunable
Polarization: Horizontal
Antenna System Bearing Error: Less than 0.5 degrees
DME Co-location: Permits coaxial mounting of DME antenna above Carrier
Number of Antenna: 48 Sidebands, 1 Carrier
Frequency Range: 108-118 MHz broadband, no tuning
Field Monitor
Antenna Type: Dipole
Number of Antennas: 1 standard, 2 optional
Frequency Range: 108 to 118 MHz
Monitor:
Azimuth Measurement Resolution: (+/-) 0.01 degree
Azimuth Measurement Range: 0 to 360 degrees
Azimuth Measurement Accuracy: (+/-) 0.2 degree

37. 37
CHAPTER 5
EQUIPMENT ROOM
Associated Officers: S.K. CHATURVEDI (SM - CNS)
5.1. Name of the equipments:
EQUIPMENTS MAKE
1. NDB SAC
2. ILS NORMAC
3. DME (High power) THALES
4. DME (Low power) THALES
5. DVOR GCEL, India
6. VHF ECIL 5000 Series, India / OTE, Italy
7. Voice Control System Drake digital 4000 Series, UK
5.1 VOICE COMMUNICATION SYSTEM
System Overview: VCS is a digital communication using a central switching matrix for routing calls
between outstation connected in a star format. This digital central switching matrix uses a
microprocessor for control & configuration purpose. It contains different digital matrix cards allowing
multiple routes to be made simultaneously and achieves all switching and routing. It also provides
analog audio, GPI (General Purpose Input) & outputs, Data interface and an advanced software
package.
A range of digital control panel is available providing a suitable user interface for making and
receiving calls.
The standard control panel provides the basic facilities of Direct Access keys (DAKs) which allow
single button operation for frequent calls.

38. 38
A call is initiated on a control panel by pressing one of the assigned DAKs or, on panels equipped with
an electronic dial keypad, by dialing a number & pressing the call button.
The cross point are activated or deactivated according to configuration rules held in system matrix map
(stored in microprocessor memory).
Number of blocks: Main Matrix; Gemini Matrix; Radio Interface; Ethernet Switch (for EPBAX and
telephone lines); Analog switching unit.
Matrix A contains: Power Supply; CPU; Hique; Codec.
Hique Card: 16 Ports; Data I/O Positions; A/D converter.
Codec Card: 16 I/O lines; 10 I/O lines used at Varanasi.
Main Distribution Frame contains: VHF Lines; Telephone Lines; Tape Recorder.
VHF Lines: Transmitter - 2 pairs (audio & PTT)
Receiver - 1 pair (audio & PTT)
Telephone lines: STD; ISD; DSC (Direct Speech Circuit); ISDN.
Positions terminated on MDF: Tower-2 positions; Area (North & South)
Name of sub-systems: (a) Touch Entry Device (TED) (b) Position Interface Unit (PIU) (c) Jack Box
(d) Headset with PTT (e) Loud Speaker
(a) TED: It is an operating position mounted on color LCD panel i.e. touch sensitive. Its position
provides the interface with central rack to initiate and respond to all radio, landline & intercom
communications for specific positions.
(b) Jack box: It is a hardwired connector interface for the operator's headset & handset.
(c) PIU: It contains the number of connections from the systems to various audio data and power
components.
(d) Speaker: The loud speaker module broadcasts received audio.
Applications:
(1) Air Traffic Control, Voice Control & integrated communication switching.
(2) Radio, landline & Intercom Communications
MASTER CLOCK
Make: Bihar communications Pvt. Limited
Reference: NPL (National Physical Laboratory), Delhi.
Purpose: To synchronize all the clocks available in different units of the airport to get same time.
Note: The Master clock is situated in the equipment room. It updates its timing with reference clock at
05:30 A.M everyday by automatic dialing. A telephone line is connected with NPL, Delhi for this
purpose.
VHF Workshop
S.no Name Type
1 VHF Set OTE
2 HHMD METOR-28
3 DFMD METOR-200
4 Tx. & Rx. 5000 Series
5 X- Bis HI-SCAN 6040i

39. 39
Test EquipmentUsed: -
1. Digital CRO (Tektronix)
2. Marconi instrument 10 KHz to 1.35GHz
3. Frequency Counter
AIR TRAFFIC SERVICES
AREA CONTROL CENTRE
Associated Officer:
Frequency Used: Area South 132.4 MHz / Stand by- 118.95 MHz
Area North 120.75 MHz/ Stand by- 119.0 MHz
Range: 220 NM
Equipment Used: (a) VCS-TED (b) Radar Screen Display (c) AK-100 (d) Printer (e) UTC Digital
clock (f) Telephone (g) Headphone with PTT.
AERODROME CONTROL TOWER
Frequency used: 118.1 MHz
Range: 25 NM
No. of equipment: (a) VCS (b) J-controller (c) walky-talky (d) Telephone Lines (e) Man pack
Status Indicators: (a) ILS (b) VOR (c) DME (d) NDB (e) VCS
RUNWAY
Orientation of Runway: 09-27
Length of Runway: 2745 m
Breadth of Runway: 45 m
Runway Indication: (a) Beacon Lights (green & white) for IFR flights/Range-Max. 40NM (15 Flashes
per/ min.) (b) Name of the airport station in large size for VFR flights.
Taxi way:3 (Three) - A, B, C.
No. of Bays: 7(Seven)
VHF EQUIPMENT ROOM DETAILS AT VARANASI STATION
1.VOICE COMMUNICATION SYSTEM (DRAKE VCS)
2. RACK1: VHF TX (OTE -7 ECIL -1)
3.RACK2: VHF RX (OTE -7)
4.RACK3: DATIS TERMA DATIS
VHF TX PAE
VHF RX PAE
5.RACK4: PAE VHF TX (3)
PAE VHF RX (3)
6.RACK5: VHF DEDICATED STAND ALONE SET UP
OTE VHF TX (3)
OTE VHF RX (3)
7.RACK6: NDB RCU
DVOR RCU
8.RACK7: DIGITAL CLOCK (BIHAR COMMUNICATIONS PVT LTD)
LOW POWER DME
LOCALIZER, GLIDE PATH REMOTE STATUS
HIGH POWER DME
9. RICOCHET DIGITAL VOICE TAPE RECORDER SYSTEM

40. 40
THE FREQUENCIES USED IN VHF COMMUNICATION AT VARANASI STATION
1.118.1 MHZ -TOWER FREQUENCY
ONESET OF DRAKE VHF TX/RX
ONESET OF DEDICATED VHF TX/RX (AK 100)
2. 119MHZ - STAND BY TOWER FREQUENCY
3.118.95 MHZ STAND BY AREA FREQUENCY
4. 120.75MHZ -AREA SOUTH FREQUENCY
ONESET OF DRAKE VHF TX/RX
ONESTANDBY SETUP OF VHF TX/RX
ONEDEDICATED STAND-ALONE SETUP OF SAME FREQUENCY
5.132.4MHZ- AREA NORTH FREQUENCY 132.4MHZ
ONESETUP OF DRAKE VHF TX/RX
ONESTANDBY SETUP OF VHF TX/RX
ONEDEDICATED STAND-ALONE SETUP OF SAME FREQUENCY
6.121.5MHZ- EMERGENCY FREQUENCY
ONESETUP OF VHF DRAKE TX/RX
ONESTANDY BY SETUP OF SAME FREQUENCY
7.126.2 MHZ- DATIS FREQUENCY
TWO SET OF VHF PAE TX/RX