A Report on
INTERNSHIP IN AIRPORTS AUTHORITY OF INDIA (AAI)
Submitted
By
NARSING DIVYA
4th year student at ANURAG UNIVERSITY
Internship Role: Intern – CNS Department
under The Supervision
of
M. Jagan Mohan Rao, AGM
Submitted
To
SMU unit, AAI Hyderabad
CONTENTS
1. Introduction
2. Systems and Technologies Covered
2.1 Instrument Landing System (ILS)
2.2 Doppler VHF Omnidirectional Range (DVOR)
2.3 Distance Measuring Equipment (DME)
2.4 Very High Frequency (VHF) Communication Systems
2.5 Voice Communication Control System (VCCS)
2.6 High Frequency Receivers
3. Airport Operations Exposure
3.1 Terminal and Airside Operations
3.2 Airport Operations Control Centre (AOCC)
3.3 Compliance and Safety
4. Key Learnings and Takeaways
5. Conclusion
1. INTRODUCTION
The Airports Authority of India (AAI) is a statutory organization functioning under the
Ministry of Civil Aviation, Government of India. Established on 1st April 1995, AAI was
formed through the merger of two key entities — the International Airports Authority of India
and the National Airports Authority. This strategic consolidation was aimed at fostering the
integrated development, expansion, and modernization of airport infrastructure across the
country, ensuring that India's aviation facilities align with international standards in terms of
safety, efficiency, and passenger experience.
Since its inception, AAI has played a pivotal role in shaping India's civil aviation landscape.
The organization is responsible not only for developing and maintaining airport infrastructure but
also for ensuring seamless air navigation and safety services across Indian airspace. As of now,
AAI manages a total of 133 airports, out of which 110 are operational and 23 are non-
operational. Among the operational airports:
• 28 are civil enclaves operating in coordination with defense airbases.
• 8 are under private control, including:
o 2 airports managed under Joint Venture (JV) agreements, and
o 6 airports operating under Public-Private Partnership (PPP) models on long-
term lease arrangements.
Moreover, 35 of these 110 operational airports support international flights, reflecting AAI’s
instrumental role in strengthening India's global connectivity and trade relations.
Apart from its airport management responsibilities, AAI is also the primary provider of Air
Navigation Services (ANS) across 2.8 million square nautical miles of airspace, covering
both domestic and international traffic regions. Its key operational responsibilities include:
• Air Traffic Control (ATC)
• Communication, Navigation, and Surveillance (CNS) systems
These functions are essential in ensuring safe, efficient, and uninterrupted air travel across the
country.
AAI also plays a significant role in setting, enforcing, and upgrading safety and security
standards throughout India’s civil aviation ecosystem. With a continuous focus on innovation,
sustainability, and modernization, AAI stands as a backbone of India's aviation growth,
supporting economic development, tourism, logistics, and connectivity at national and
international levels.
2. SYSTEMS AND TECHNOLOGIES COVERED
2.1 Instrument Landing System (ILS)
Function: Provides precise horizontal and vertical guidance to aircraft during landing,
especially in low visibility.
It includes:
Localizer (LLZ): Offers lateral guidance.
Installation: 300 meters beyond the upwind end of the runway.
Antenna: Typically, a 20 m wide, 3 m high frangible array consisting of dipoles and reflectors.
Signal Pattern: Two overlapping lobes—90 Hz modulation on the left (Yellow sector) and 150
Hz on the right (Blue sector). The receiver determines the aircraft’s position relative to the
centreline using DDM (Difference in Depth of Modulation).
Glide Path (GP): Offers vertical guidance.
The Glide Path (or Glide Slope) provides vertical descent guidance and operates in the UHF
band (329.15 to 335 MHz) using two lobes:
Upper lobe: 90 Hz
Lower lobe: 150 Hz
The aircraft uses DDM to determine whether it is above or below the optimal glide path, which is
typically set at 3°, but may range from 2° to 4°. For example, London City Airport uses a glide
path of 5.5°.
Location: ~300 meters upwind from runway threshold and 120 m from centreline.
Glide Path Range:
Azimuth: ±8°
Vertical: 0.45θ to 1.75θ (where θ is the nominal glide angle)
Distance: 10 NM
Critical and Sensitive Areas
Critical Area: No aircraft or vehicle movement allowed during ILS operation.
Sensitive Area: Controlled vehicle movement to prevent signal interference.
ILS is indispensable for Category I/II/III approaches and must meet ICAO Annex 10
standards. Critical and sensitive areas around the runway must remain clear during
operation.
2.2 Doppler VHF Omnidirectional Range (DVOR)
Function: Provides azimuth information to aircraft for enroute and approach navigation.
System Studied: MARU 220 DVOR by Mopiens.
Key Highlights:
48 directional antennas simulate Doppler effect.
Includes redundancy with dual amplifiers and monitoring units.
Remote monitoring via LMMS/RMMS for efficient management.
High-frequency stability with centralized power control.
This system ensures continuous and accurate navigation support, especially in high-
density air routes.
2.3 Distance Measuring Equipment (DME)
Function: Measures slant range distance between aircraft and ground station.
Operating Range:
962–1213 MHz (UHF).
System Characteristics:
Works alongside DVOR/ILS.
Offers real-time updates with ±0.1 NM accuracy.
Terminal and En-route variants available.
The DME helps pilots confirm their position, contributing to safe spacing and navigation.
2.4 Very High Frequency (VHF) Communication Systems
Function: Facilitates ground-to-air communication using line-of-sight radio waves
(117.975–137 MHz).
System Studied: Park Air T6 Radios
Features:
Digital modulation, AM voice & VDL Mode 2.
Satellite-based relays for remote coverage.
IPv4/IPv6 compatibility and remote diagnostics.
These radios are the primary communication link between pilots and controllers in most
Indian airspace.
2.5 Voice Communication Control System (VCCS)
System Studied:
SITTI MULTIFONO VCCS
Function: Manages all radio and telephony communication for ATC.
Highlights:
Modular, fault-tolerant architecture.
SIP and RTP protocols for digital communication.
Used at Area Control Centres, Towers, and AOCCs.
Reliable voice communication is central to safe air navigation, especially during sector
transitions and emergencies.
2.6 High Frequency (HF) Receivers
Use: Communication over long distances, oceanic airspace.
Modern Trend: Software Defined Radio (SDR) approach.
Receiver Specs:
10 kHz to 30 MHz frequency range.
Dual IF stages for high sensitivity (48.048 MHz and 48 kHz).
FPGA and controller-based management.
HF remains crucial where satellite or VHF coverage is limited.
3. Airport Operations Exposure
3.1 Terminal and Airside Operations
Monitored apron control, terminal movement, and serviceability of passenger facilities.
Learned about emergency protocol handling and coordination with airlines, ground
handlers, and ATC.
3.2 Airport Operations Control Centre (AOCC)
Central command for real-time flight, gate, and apron management.
Enhances responsiveness to delays, diversions, and VVIP movement.
3.3 Compliance and Safety
Gained technical understanding of CNS systems, their components, redundancy, and fault
detection.
Understood interdisciplinary roles in managing air traffic and airport operations.
Exposure to real-time system monitoring tools enhanced operational awareness.
Developed appreciation for regulatory compliance, documentation, and international
aviation standards.
4. KEY LEARNINGS AND TAKEAWAYS
Strict adherence to ICAO SARPs, DGCA CARs, and coordination with security agencies.
5. CONCLUSION
The internship at SMU, AAI Hyderabad, was an enriching experience that bridged
academic learning and real-world application. It deepened my understanding of aviation
systems and airport operations, and strengthened my interest in the field of aviation
electronics, communication, and operations management
References:
• Noridian Navigation Systems. (n.d.). Radio Navigation Systems – EASA Training
Module (Demo). Retrieved from
https://www.nordian.net/REPOSITORY/111_easa_radio_navigation_demo.pdfMopiens
Inc. (2019). MARU 220 DVOR/DME Technical Manual.
• (Provided during AAI internship sessions)
• AAI Training Material – CNS/ATM Systems, AAI Hyderabad Unit. (2025).
(Internal documentation)
