Circular No. 44/2014/TT-BGTVT on the methods of air-ground communication for civil aviation

CIRCULAR

Provisions on non-radar air-ground communication for civil aviationg

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Pursuant to the Civil Aviation Law of Vietnam dated June 29, 2006;

Pursuant to Decree No. 107/2012/NĐ-CP dated December 20, 2012 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Transport;

Pursuant to Decree No. 94/2007/NĐ-CP dated June 4, 2007 of the Government on Air Traffic Management;

At the proposal of the Director of the Transport Department and the Director General of the Civil Aviation Authority of Vietnam.

The Minister of Transport issues this Circular to provide provisions on non-radar air-ground communication for civil aviation.

PART I

GENERAL PROVISIONS

Article 1. Scope of Regulation and Applicability

1. This Circular stipulates the methods of non-radar air-ground communication between flight crews and air traffic controllers within Vietnamese airspace, international waters overflown by Vietnam, and foreign flight information regions authorized by Vietnam to provide air traffic services.

2. This Circular applies to organizations and individuals related to non-radar air-ground communication for civil aviation in Vietnam.

Article 2. Abbreviations

In this Circular, the following abbreviations shall be understood as follows:

1. ACC (Area Control Centre). Area Control Centre.

2. ADS (Automatic Dependent Surveillance)Automatic Dependent Surveillance.

3. AIP (Aeronautical Information PublicationAeronautical Information Publication, including permanent and necessary information for flight operations.

4. ATS (Air Traffic ServicesAir Traffic Services.

5. CPDLC (Controller-Pilot Data Link CommunicationsController-Pilot Data Link Communications.

6. ETA (Estimated Time of ArrivalEstimated Time of Arrival.

7. FANS-1/A (Future Air Navigation System-1/AFuture Air Navigation System-1/A.

8. FIR (Flight Information Region)

9. ISL (International Civil Aviation OrganizationFlight Information Region.

10. ICAO (International Civil Aviation OrganizationInternational Civil Aviation Organization.

11. IFR (Instrument Flight RulesInstrument Flight Rules.

12. HF (High FrequencyHigh Frequency (from 3.000 to 30.000 Kilohertz).

13. SSR (Secondary Surveillance RadarSecondary Surveillance Radar.

14. UTC (Coordinated Universal TimeCoordinated Universal Time.

15. Specific Conditions (Operating mode for survey:VHF

16. FOM (Very High FrequencyVery High Frequency (from 30 to 300 Megahertz).

Article 3. Explanation of Terms

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Flight Operations Manual

Flight Operations Manual.

1. Non-radar air-ground communication refers to two-way communication between air traffic controllers and flight crews.

2. An IFR flight is a flight conducted under instrument flight rules.

3. A VFR flight is a flight conducted under visual flight rules.

4. Air traffic service facility is a general term referring to air traffic control facilities, information centers, coordination centers, or clearance offices.

5. Air traffic services (ATS) is a general term encompassing flight information services, alerting services, advisory services, and air traffic control services (en-route control, approach control, and airport control).

6. Reporting point is a specified geographical location from which aircraft can report their position.

7. Altitude is the vertical distance from mean sea level to a point, a surface, or an object considered as a point.

8. Air traffic control instruction is an instruction issued by an air traffic control facility to an aircraft to conduct a flight according to conditions prescribed by the facility, which may include terms such as "taxi," "takeoff," "departure," "en route," "approach," and "landing" to indicate parts of the flight covered by the instruction. It may be referred to as "instruction" when used in appropriate context.

9. Nose direction is the longitudinal axis direction of the aircraft, usually expressed in degrees from true, magnetic, or compass north or grid north.

10. Flight plan is information provided to an air traffic service facility regarding a planned flight or part thereof.

11. Air traffic controller (ATC) is a general term referring to ground controllers at airports, airport controllers, approach controllers, and en route controllers.

12. Flight level is an altitude reference to a standard pressure of 760 mmHg (1013.2 mb) and specified pressure altitudes above that level.

13. Aircraft operator is defined in Article 22 of the Civil Aviation Law 2006.

14. Air traffic control regulations are regulations promulgated together with Decision No. 32/2007/QĐ-BGTVT dated July 5, 2007, of the Minister of Transport.

15. Broadcast is the transmission of information related to flight operations without specifying a particular station.

16. Annex 10 is the International Civil Aviation Organization's Standards and Recommended Practices concerning Aeronautical Telecommunications.

17. Doc 4444 PANS-ATM is the ICAO's Air Traffic Management Manual.

18. Doc 9432 AN/925 of ICAO is the ICAO's Manual of Radiotelephony.

19. Runway Visual Range (RVR) is the distance along the runway centerline that a pilot can see runway markings, edge lights, or touchdown zone lights while on the runway.

Article 4. General provisions on air-ground communication assurance

1. Air-ground communication assurance for flight crews shall be carried out in accordance with the provisions of Article 34 of the Procedural Rules for Air Traffic Control.

2. Air-ground communication assurance for air traffic service providers shall be carried out in accordance with the provisions of Section 1, Chapter V of the Procedural Rules for Air Traffic Control.

3. The frequencies, operating modes, and coverage ranges of VHF air-ground communications shall be detailedly published by the Civil Aviation Administration of Vietnam through the Vietnam Aeronautical Information Publication (AIP) for each air traffic service provider in Vietnam.

4. The primary language used in air-ground communication is English; in cases of safety reasons, Vietnamese flight crews may use Vietnamese.

Article 5. Methods of air-ground communication

1. Voice air-ground communication method (Voice communication via VHP, HF).

2. Data air-ground communication method (Data communication via ADS/CPDLC).

Chapter II

VOICE AIR-GROUND COMMUNICATION METHODS

Article 6. General Provisions

1. Voice communication methods shall be implemented according to Annex 10 Volume II - Communication Procedures, Document 4444 PANS-ATM and Document 9432 AN/925 of the International Civil Aviation Organization (ICAO) and any amendments or supplements (if applicable).

2. Voice communication methods shall be used in the following situations:

a) Airport control services, ground control services;

b) Radar control;

c) Approach control services;

d) En-route control services;

e) Emergency, distress, and communication failure situations;

f) Transmission of weather information and other airport-related information;

g) Handling abnormal crew situations.

Article 7. Technical transmission rules

1. Technical transmission rules are specified as follows:

a) Before transmitting, listen on the frequency being used to ensure that there will be no interference when another station is transmitting;

b) Use standard intonation, clear pronunciation, and coherent speech;

c) Maintain an average speaking rate not exceeding 100 words per minute. Pause slightly before and after numbers to aid comprehension. When elements of the message are recorded by the recipient, speak at a slower pace;

d) Maintain a stable volume level;

e) Do not use hesitation words such as "ah, um, uh";

f) Maintain a consistent distance between the mouth and the microphone;

g) Temporarily stop transmitting if necessary or when changing the distance between the mouth and the microphone;

h) Press and hold the transmit button before transmitting and do not release it until the entire message has been transmitted to ensure complete transmission;

i) In case of necessity, when transmitting long messages, break them up to allow the transmitter to confirm that the transmission frequency is not being interfered with by another station and to allow the receiver to request retransmission of parts not received.

2. Potential dangerous situations when the transmit button gets stuck during voice communication. To ensure safety, the person pressing the button to speak must release the button after transmitting and ensure that the button is not inadvertently activated.

Article 8. Pronunciation rules for letters

1. Letters shall be pronounced according to the ICAO standard as shown in the table below. The bolded parts are the stressed syllables, which should be emphasized when pronouncing.

2. Except for contact addresses and aircraft types, letters in the aircraft call sign should be pronounced according to ICAO standards when the aircraft call sign is the registration number.

Article 9. Pronunciation rules for digits

1. Digits shall be pronounced as follows. The syllables printed in capital letters will be emphasized.

2. All numbers used to transmit and read information on altitude, cloud height, visibility, and runway visual range (RVR), which include hundreds and thousands, shall be pronounced digit by digit within the hundreds or thousands cluster, followed by the word "TRĂM" or "NGHÌN" as appropriate. The combination of thousands and hundreds clusters shall be pronounced digit by digit within the thousands cluster, followed by the word "NGHÌN", then the hundreds cluster followed by the word "TRĂM".

ONE ONE EIGHT DECIMAL ZERO (One one eight point zero)

1. When reading time, the flight crew and air traffic control service (ATCS) shall pronounce the minutes of the hour separately. In cases where confusion may arise, the hour must also be read.

0920 (9:20 AM)

Term/Phrase

Understanding

ACKNOWLEDGE

Approach control radar arrivals

(Kiểm soát tiếp cận ra đa đối với tàu bay đến)

The name of the aircraft manufacturer or model name will be used as a prefix for radio communication, together with corresponding characters to the aircraft registration mark.

When radio communication is established and there is no possibility of confusion, the aircraft call signs prescribed in point a of this clause may be abbreviated as follows:

The first letter and at least two final characters of the aircraft registration mark

When non-voice communication is established and there is no possibility of confusion, the aircraft call sign specified in Point a Clause 2 shall be abbreviated as follows:

c) The flight crew may use the abbreviated aircraft call sign after being called in this manner by an air traffic control unit.

d) The flight crew shall not change the type of aircraft call sign during the flight except where there is a risk of confusion due to similar call signs. In such cases, the Air Traffic Control Unit has the authority to temporarily change the aircraft call sign in its area of responsibility.

Article 13. Provisions on Communication

1. Establishing and Maintaining Communication

a) When establishing communication, the flight crew must use the full name of the aircraft and the air traffic service provider;

b) When the air traffic service provider wishes to broadcast announcements, the radiogram must begin with the phrase “All Stations”. In this case, the flight crew does not need to acknowledge receipt;

c) The provisions for requesting the retransmission of the entire or part of the radiogram are as follows:

d) When it is necessary to correct a communication error, the term "CORRECTION" (Correction) must be used, followed by the repetition of the last group or phrase and then the transmission of the accurate version. When correcting a communication error, the entire radiogram should be repeated, and the transmitting station should use the phrase "CORRECTION, I SAY AGAIN" (Correction, I repeat) before retransmitting the radiogram;

e) When receiving a radiogram is difficult, important information in the radiogram must be transmitted twice.

2. Transfer of Communication

a) The transferring facility is responsible for informing the aircraft of the frequency of the receiving facility according to the air traffic control agreement. In the absence of such notification, the aircraft is responsible for informing the transferring facility before changing frequencies;

b) The aircraft may be instructed to stand by (STAND BY) on a frequency when it is expected that the air traffic service provider will initiate communication and monitor (MONITOR) on the frequency where information is being transmitted.

3. Issuing and Repeating Air Traffic Instructions

a) Air traffic instructions are defined in the Air Traffic Control Regulations;

b) The air traffic controller is responsible for issuing slow and clear instructions to allow the flight crew sufficient time to record them and avoid the need to repeat instructions, which would waste time. Long-range instructions must be issued to the flight crew before engine start-up. The air traffic controller does not issue long-range instructions to the flight crew during complex taxi maneuvers, takeoff roll, or takeoff;

c) Long-range instructions are not directives for takeoff or entry into an active runway. The term "TAKE OFF" is only used when the aircraft is permitted to take off, when canceling a takeoff instruction, or when canceling a takeoff. At other times, the terms "DEPARTURE" or "AIRBORNE" are used;

d) The purpose of repeating instructions is to ensure flight safety, prevent misunderstandings between the issuance and receipt of instructions and air traffic control directives;

e) Instructions to be repeated include: air traffic control instructions, instructions and directives for approach, takeoff, holding, crossing, and backtracking on the runway; information about the runway in use, assigned altimeter setting, SSR code, flight level directive, heading, and speed;

f) The flight crew is responsible for repeating or acknowledging receipt of other instructions and directives, including conditional instructions, to ensure that the crew understands and will comply with them. The flight crew ends the repetition of instructions with the aircraft's call sign;

g) The air traffic controller is responsible for listening to the flight crew's repetition to ensure that other instructions or directives have been acknowledged accurately and must promptly correct any discrepancies in the repetition. If the flight crew repeats instructions and directives inaccurately, the air traffic controller uses the term "NEGATIVE I SAY AGAIN" (Negative, I repeat) along with the corrected content;

h) In cases of doubt regarding the execution of instructions and directives, the air traffic controller must issue an instruction or directive accompanied by the phrase "IF UNABLE" (If unable) and provide additional backup instructions or directives. If the instruction or directive cannot be executed, the flight crew must inform the air traffic controller using the phrase "UNABLE" and provide the reason.

Article 14. Communication Check Procedures

1. The communication check procedures shall be conducted in the following order: name of the service provider facility; aircraft call sign; transmission of the phrase "RADIO CHECK" (radio check); frequency in use.

2. The flight crew shall respond to the communication check items specified in Clause 1 of this Article in the following order: name of the calling station; name of the responding station; information related to the quality of transmission.

3. Transmission quality shall be classified according to the following levels:

a) Level 1: Unreadable (Unreadable);

b) Level 2: Readable now and then (Readable now and then);

c) Level 3: Readable but with difficulty (Readable but with difficulty);

d) Level 4: Readable (Readable);

e) Level 5: Perfectly readable (Perfectly readable).

4. The communication check with a ground station, accompanied by transmitter and receiver adjustments, shall not exceed ten seconds (transmitting station's radio call sign and counting one, two, three...).

Article 15. Special Provisions for Pronunciation of Certain Terms

1. For certain abbreviations of commonly used terms in aviation operations (such as ILS, QNH, RVR...) shall be pronounced using letters instead of pronouncing them as prescribed in Article 8 of this Circular.

2. The following terms may be omitted provided there is no risk of misunderstanding:

a) "SURFACE" when transmitting surface wind direction and speed;

b) "DEGREES" when transmitting heading according to radar control instructions;

c) "VISIBILITY" (visibility), "CLOUD" (cloud), and "HEIGHT" (height) in weather reports;

d) "HECTOPASCALS" when providing atmospheric pressure.

3. In non-radar air-ground communications, courteous terms should not be used.

4. The term "IMMEDIATE" (immediate) shall only be used when immediate action is required for safety reasons.

Article 16. Instructions on Altitude and Flight Level

The flight crew and air traffic controllers are responsible for:

1. Ensuring that no confusion arises from the use of different types of terminology to specify altitude and flight level.

2. Repeating the entire instruction on altitude and flight level if any change occurs in the content of the instruction.

Article 17. Position Reports

1. A position report includes the following information:

a) Aircraft identification information;

b) Aircraft position;

c) Time;

d) Flight level or altitude including the flight level being flown through, assigned flight level, if the assigned flight level cannot be maintained;

e) Next position, time over;

f) Next significant point.

2. Information at points d, e, and f of Clause 1 of this Article need not be reported if the ATC has informed the flight crew and the operational environment uses radar. Information at point d of Clause 1 of this Article shall be reported during the first communication contact after the aircraft changes communication frequency.

3. When the service provider facility uses radar surveillance, the ATC may not require the flight crew to report at mandatory reporting positions.

Article 18. Flight Plan

1. In case of emergency, the flight crew shall submit the flight plan to the service provider facility while in flight, transitioning from IFR to VFR flight. The format and details of the flight plan shall be carried out according to ICAO Document 9432 AN/925.

2. When the flight crew reports transitioning from IFR to VFR flight, the ATS facility must provide meteorological information to the flight crew.

Chapter III

DATA COMMUNICATIONS PROCEDURES (ADS/CPDLC)

Article 19. Data Link Communication Airspace

1. For aircraft equipped with data link communication, ADS/CPDLC shall be the primary means of communication and VHF/HF voice communication shall be the secondary means. Depending on traffic volume, air traffic service providers may also use ADS/CPDLC within the coverage area of VHF voice communication if there is still a connection.

2. All aircraft equipped with FANS-1/A and connected to ADS/CPDLC will be informed of the frequency for monitoring during the provision of data link communication services. The ADS/CPDLC connection will be established automatically or manually at the ground system after the login procedure is completed.

3. ADS/CPDLC will be used as the monitoring means outside radar coverage, and the application of ADS will not change current position reporting methods (ADS-C will not be used for separation between aircraft).

Article 20. ADS/CPDLC Login Procedure

1. All ADS/CPDLC connections must require logging in with the Air Traffic Service Advisory Function (AFN).

2. The flight identification number and aircraft registration when logging in must match the flight identification number and aircraft registration in the filed ATS flight plan.

3. The notification airspace for ADS/CPDLC login addresses is determined and published by the Civil Aviation Authority of Vietnam in the Vietnam Aeronautical Information Publication (AIP).

4. Aircraft equipped with FANS-1/A requiring data link communication services, when flying from notification airspace without data link communication or airspace providing radar service into airspace with data link communication, must log in to the notification airspace address approximately 15 to 45 minutes before entering the airspace with data link communication. The CPDLC/ADS-C connection will be established automatically or manually by ACC after the login procedure is completed. The flight crew must transfer position reports to the relevant air traffic service provider using CPDLC at the first mandatory reporting point after the CPDLC connection is established.

5. Aircraft equipped with FANS-1/A being provided data link communication services, when transitioning from one notification airspace to another, will automatically transfer according to the handover address procedure or according to the instructions of the transferring air traffic service provider to log in manually to the next notification airspace address at an appropriate time/distance before reaching the boundary of the notification airspace. The flight crew must transfer position reports to the relevant air traffic service provider using CPDLC at the boundary of the notification airspace after the CPDLC connection is established.

Article 21. ADS/CPDLC Operation Method

1. When entering airspace with data link communication, all aircraft establishing data link communication with the air traffic service provider must transmit aircraft position report data through ADS/CPDLC at the boundary of the notification airspace. If the CPDLC position report has been sent via FOM and the flight crew has received a reply message from the air traffic service provider, the flight crew does not need to report the aircraft's position again via voice communication unless requested by the air traffic service provider.

2. Voice communication between the air traffic service provider and the flight crew initiated by voice communication shall be concluded by voice communication, and communication initiated by ADS/CPDLC shall be concluded by ADS/CPDLC to ensure synchronization and accuracy of messages.

3. ADS/CPDLC must be the primary means of communication when the air traffic service provider instructs the flight crew to "MONITOR [name of agency] [frequency]".

4. The flight crew responds with the phrase "WILCO" indicating that the instruction has been fully understood and will be followed.

5. It is not mandatory for the flight crew to repeat air traffic control instructions transmitted via CPDLC.

6. The message "STAND BY" indicates that the request is being processed and a short wait is expected.

7. The message "REQUEST DEFERRED" indicates that the request is being processed and a longer wait (extended period) is expected.

8. The content of a CPDLC message sent should contain only one request for instructions to avoid possible misunderstandings.

9. If multiple instructions are contained in the same received message and the ATS unit cannot resolve all requests immediately, the response message to the aircraft should initially state "UNABLE". Subsequently, the ATS unit must respond to each item individually, each in a separate message as required by the flight crew.

10. In case of doubt about the content of a message, clarification must be made through voice communication.

11. Preformatted message components shall be used in all cases. Unformatted message components shall only be used when there are no suitable preformatted message components available or when supplementing existing preformatted message components. Requests for instructions and responses to such requests shall be made using preformatted message components.

12. Standard air traffic control terminology and standard message formats must be used when receiving non-standard messages. Non-regulatory terms or phrases shall not be used.

Article 22. Limitations of ADS/CPDLC Services

1. In case of emergency, the flight crew shall inform the service provider about the situation using the most appropriate communication method available (voice communication or ADS/CPDLC).

2. Upon receiving an ADS/CPDLC message with the content MAYDAY (distress) or PAN (urgency), the service provider shall respond with a free text message to the aircraft with the content ROGER MAYDAY (distress) or PAN (urgency).

3. When the emergency situation no longer exists, the flight crew shall deactivate the ADS/CPDLC emergency mode (if activated).

4. If the flight crew observes or becomes aware of any unusual phenomena related to flight operations, they must report it to ATS through voice communication.

5. When the service provider applies radar separation between aircraft, the flight crew must maintain voice communication on VHF frequency and ADS/CPDLC shall not be used.

Article 23. Termination of ADS/CPDLC Communication Service

1. For flights entering and exiting FIRs providing ADS/CPDLC services: Aircraft equipped with FANS-1/A will automatically transmit the "FN_CAD" message 15 minutes before crossing the FIR boundary to initiate the electronic log-in process for the next ATS region's ATM system. Once the next service provider accepts control of the flight, a "CONTACT or MONITOR [ATS unit name] [frequency]" message will be transmitted 5 minutes before crossing the FIR boundary, and an "END SERVICE" message will be automatically transmitted at the FIR boundary. In the event of automatic log-in failure, the "END SERVICE" message will be manually transmitted to the aircraft no later than when the aircraft enters the FIR boundary or as soon as possible.

2. For flights entering and exiting FIRs without ADS/CPDLC services: Aircraft equipped with FANS-1/A will have the "CPDLC CONTACT [ATS unit name] [frequency]" message transmitted 5 minutes before crossing the FIR boundary or sector boundary. The flight crew must confirm receipt of this message by transmitting "WILCO". When the aircraft leaves the area with data link communications, the service provider must transmit an "END SERVICE" message to the aircraft to indicate the termination of CPDLC connection.

Article 24. Flight Plan Filing

The flight crew or aircraft operator responsible for implementing the ADS/CDPLC communication method shall enter the following information into Section 10 of the ICAO Standard Flight Plan Form, specifically as follows:

1. Section 10 - Letter "J" indicating data link communication capability.

2. Section 10 - Letter "D" under Surveillance indicating ADS-C capability.

3. Section 18 - Letters DAT followed by one or more appropriate letters indicating the type of equipment installed if letter "J" is entered in Section 10.

Article 25. Loss of Data Link Connection

1. When the ADS/CPDLC connection cannot be established, the flight crew shall select "ATC Com Off" and then begin logging into another AFN. If the CPDLC connection continuously fails, the flight crew must re-establish voice communication on the appropriate frequency.

2. Upon detecting a failed ADS/CPDLC connection, the flight crew must inform the service provider of the situation via the appropriate voice communication frequency and immediately cease the CPDLC connection. If possible, by selecting "service provider Com Off".

Article 26. Address for receiving incident reports

The flight crew, aircraft operators, and air navigation service providers encountering incidents with data transmission must prepare and submit incident reports to the Civil Aviation Authority of Vietnam at the following address:

Flight Operations Management Department, Civil Aviation Authority of Vietnam;

No. 119 Nguyen Son Street, Long Bien District, Hanoi City;

Telephone: 84-4-38274191/38723600; Fax: 84-4-38274194; AFS: VVVVYAAN;

Email: [email protected]. Website of the Civil Aviation Authority of Vietnam: http://www.caa.gov.vn.

Chapter IV

RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS INVOLVED

Article 27. Responsibilities of the Civil Aviation Authority of Vietnam

1. Implement this Circular, and update new content related to flight safety operations.

2. Guide the implementation of voice communication procedures and data communication methods for relevant organizations and individuals.

3. Summarize and report to the Ministry of Transport any issues or difficulties arising during implementation for research and timely resolution.

Article 28. Responsibilities of Air Navigation Service Providers

1. Implement this Circular for units, departments, control tower staff, and other personnel involved in air-ground communications.

2. Train control tower staff and other relevant personnel to ensure compliance with air-ground communication procedures.

3. Report any issues or difficulties encountered during implementation to the Civil Aviation Authority of Vietnam for consolidation and recommendation to the Ministry of Transport.

Article 29. Responsibilities of Airlines

1. Implement this Circular for units, departments, flight crews, and other personnel involved in air-ground communications.

2. Train flight crews and other relevant personnel to ensure compliance with air-ground communication procedures.

3. Report any issues or difficulties encountered during implementation to the Civil Aviation Authority of Vietnam for consolidation and recommendation to the Ministry of Transport.

Chapter V

IMPLEMENTING PROVISIONS

Article 30. Effectiveness and Responsibility for Enforcement

1. This Circular takes effect from December 1, 2014.

2. The Director of the Ministry's Office, the Inspector General of the Ministry, Heads of Departments, Directors of the Civil Aviation Authority of Vietnam, Heads of agencies, organizations, and individuals concerned are responsible for enforcing this Circular./.