AN INTRODUCTION TO COMMUNICATION, NAVIGATION, SURVEILLANCE SERVICES PROVIDED BY VATM
1. Aeronautical communication services
1.1. Aeronautical Mobile communications
Aeronautical mobile communications, also known as Air/Ground Communications, is the communication between pilots and air traffic controllers. This communication is made via Very High Frequency (VHF) communication system at 118 MHz to 137 MHz.
In order to ensure communication between pilots and air traffic controllers at each stage of air traffic management (aerodrome (TWR, GCU), approach and area control), VHF stations are installed in a meticulously and optimally. All 22 airports across the country have VHF stations installed for aerodrome control; VHF stations at airports have GCU units such as Noi Bai, Da Nang, Tan Son Nhat,…; Approach VHF stations provide approach control at Noi Bai, Da Nang, Tan Son Nhat,…; Area control VHF stations are installed along the North – South Axis at Moc Chau, Cat Bi, Vinh, Son Tra, Chu Lai, Quy Nhon, Buon Ma Thuot, HCM, Ca Mau, Truong Sa Lon and Song Tu Tay to provide area control. Each area control VHF station has the maximum reach of 250 NM, equivalent to 450 km.
With the current VHF system, VHF waves have the coverage over all of Viet Nam’s FIRs. Moreover, the East Sea area of Ho Chi Minh FIR’s communication is enhanced with High Frequency (HF) and Controller Pilot Data Link Communication (CPDLC) from June 2011.
1.2. Aeronautical Fixed Telecommunication Network (AFTN)
Air Traffic Service/Direct Speech (ATS/DS) is direct-speech communication for air traffic controllers to communicate information between domestic and local countries’ ATC units. This type of communication uses direct hotlines via aviation’s private satellite networks or via renting exclusive channels from domestic and international providers.
Aeronautical Fixed Telecommunication Network is a text communication network between units related to air trafic management activities, airports, aircraft operations and aviation authorities. AFTN has several Automatic Message Switching Systems (AMSS) located at the northern (Ha Noi), middle (Da Nang), southern (HCMC) regions. Additionally, VATM implemented the Aeronautical Message Handling System (AMHS) to gradually replacing AFTN systems according to ICAO requirement. The system is developed by the Air Traffic Technical Company (ATTECH).
2. Aeronautical Navigation Services
Aeronautical Navigation Services’ missions are: Helping aircrafts determining their exact position on flight routes; support pilots implementing flight procedures for take off and landing; and support aircrafts staying within their flight routes and arriving at their determined destination, not violating air traffic rules or threatening the safety of personel and asset on aircraft or on the ground. To be able to perform these missions, VATM is currently managing and operating ground navigation equipment and systems, mainly located at Viet Nam airports including Non Directional Beacon (NDB) at Moc Chau, Nam Dinh and Long Khanh as well as Very High Frequency Omnidirectional radio range/Distance Measuring Equipment (VOR/DME) at Dien Bien, Noi Bai, Vinh Phuc, Nam Ha, Cat Bi, Tho Xuan, Vinh, Dong Hoi, Da Nang, Phu Bai, Chu Lai, Pleiku, Phu Cat, Buon Ma Thuot, Cam Ranh, Lien Khuong, Phan Thiet, Tan Son Nhat, Can Tho, Phu Quoc, Con Son, Rach Gia, Tuy Hoa.
According to Decision No. 22/QD-BGTVT dated 28/11/2019 issued by Ministry of Transport on Approving modified master plan of developing Viet Nam civil aviation CNS/ATM system to 2020 and orientation to 2030, DVOR/DME systems are oriented from DVOR/DME based navigation to mainly Performance Based Navigation (PBN), with DVOR/DME system as contingency. Therefore, VATM is by-step implementing the transition and application of PBN to be compatible with the national master plan as well as the global aeronautical navigation trend.
3. Aeronautical Surveillance Services
Aeronautical Surveillance service has supported air traffic controllers to identify aircraft, their positions on radar displays at controllers’ working positions. The surveillance service is performed by the radar surveillance, ADS-B, ADS-C and MLAT systems. VATM is currently operating the following surveillance systems:
+ Radar systems for area and approach control: including PSR/SSR radar systems having primary surveillance radar installed with Secondary Surveillance Radar, and systems with Secondary Surveillance Radar only;
+ ADS-B systems: systems with Tier-1 configuration (02 recorders, 02 independent lines minimum) installed across the country (Dien Bien, Pha Din, Noi Bai, Van Don, Cat Bi, Tho Xuan, Vinh, Dong Hoi, Phu Bai, Da Nang, Chu Lai, Phu Cat, Pleiku, Tuy Hoa, Buon Ma Thuot, Lien Khuong, Ba Queo, Can Tho, Ca Mau (2 stations), Phu Quoc, Con Son.
+ ADS-C service is used to perform air traffic management over the ocenic area within Ho Chi Minh FIR.
+ Surface surveillance systems include Surface Movement Radar (SMR) at Noi Bai, Da Nang International Airport, and MLAT system at Phu Quoc International Airport.
Radar systems and ADS-B network have the coverage over Ha Noi FIR and Ho Chi Minh FIR within Viet Nam’s area of responsibility. Additionally, in order to enhance the ability of coordination-air traffic management with nearby countries. VATM is sharing ADS-B surveillance data from Con Son and Ca Mau ADS-B stations for Civil Aviation Authority of Singapore.
