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3. Coordination & Handover

3.1 Handover/Takeover Procedures

Handover and takeover of aircraft between controllers or sectors within the Muscat FIR are primarily facilitated through the TopSky ATM system. When all relevant flight information—including identification, position, altitude, route, and clearances—is correctly reflected on the aircraft’s electronic tag, no additional verbal coordination is required. This “silent” handover allows controllers to transfer responsibility seamlessly without voice communication, reducing frequency congestion and workload.

However, if the handover involves any deviations, special conditions, or requires confirmation beyond the data displayed on the system, controllers shall initiate voice coordination with the receiving controller. This verbal communication ensures clarity and confirms mutual understanding of any special instructions, restrictions, or traffic conflicts before completing the transfer.

The handover process must be completed well in advance of the aircraft reaching the sector boundary to provide sufficient time for situational awareness and timely intervention if needed. Both transferring and receiving controllers remain responsible for continuous monitoring until the handover is fully accepted.

3.2 Intra-FIR Coordination (between sectors)

Coordination between sectors within the Muscat FIR is primarily managed through the TopSky ATM system, which enables silent electronic exchange of flight data such as position, altitude, speed, and route. When all necessary information is accurately reflected on the system and there are no special conditions or conflicts, no verbal coordination is required, facilitating efficient traffic management and reducing communication load.

If, however, there are deviations, potential conflicts, or operational constraints that require clarification or agreement, controllers shall conduct voice coordination to ensure mutual understanding. This includes coordination of clearance changes, estimated times of sector entry, or resolving workload issues. All coordination must be completed in a timely manner to maintain safety and smooth traffic flow.

3.3 Inter-FIR Coordination (adjacent FIRs)

Coordination with adjacent FIRs is conducted through a combination of silent electronic data exchange and voice communication. Routine flight plan data, estimated entry and exit times, and standard clearances are shared electronically when systems allow, minimizing the need for voice contact and reducing frequency congestion.

Voice coordination is required when there are non-standard conditions, such as deviations from the flight plan, emergencies, or traffic conflicts that need immediate resolution. Controllers must ensure that all transferred information is confirmed and understood by both parties before transfer of control and communication.

Coordination is particularly critical when liaising with Mumbai Oceanic or Sanaa Radio, as these units operate predominantly under procedural separation due to the absence of radar coverage in their airspace. Accurate and timely exchange of information in these cases is essential to maintain safe separation and ensure smooth transitions between radar-controlled and procedural environments.

Clear and timely coordination between FIRs is essential to maintain safe separation, comply with letter of agreements, and optimize traffic flow across boundaries.

3.4 Transfer of Communication

The transfer of communication involves shifting radio contact of the aircraft from one controller to another. When using automated ATM systems like TopSky, this transfer is often preceded by a silent handoff, where the aircraft’s flight data is electronically passed to the receiving controller’s display without the need for immediate voice coordination, provided no special instructions or conflicts exist.

Prior to transferring communication, the transferring controller must inform the pilot of the upcoming frequency change, providing the new frequency and ensuring the pilot’s acknowledgment. The receiving controller will only accept the aircraft’s electronic tag once the aircraft establishes radio contact by calling up on the new frequency.

If the receiving controller does not assume the aircraft tag within a reasonable timeframe, it indicates the aircraft has not yet contacted the next sector, and the transferring controller remains responsible for providing services until contact is established.

3.5 Transfer of Control

The transfer of control is the formal passing of responsibility for an aircraft’s separation and navigation from one controller or sector to another. This transfer must be effected at least 20 nautical miles or 10 minutes prior to the aircraft reaching the FIR boundary, unless otherwise agreed between adjacent units. This ensures the receiving controller has adequate time to assume control and maintain safe separation.

Transfer of control can be performed as a silent handoff via the ATM system when all flight data is correctly displayed and no special coordination is needed. The transferring controller retains responsibility until the receiving controller explicitly accepts control by assuming the aircraft’s electronic tag, which occurs after the aircraft has established radio contact on the receiving controller’s frequency.

There are three types of transfer conditions that define the extent of control delegated to the receiving controller:

  • Full: The receiving controller has full freedom to manage the aircraft’s route, speed, and altitude as necessary.
  • Turn: The receiving controller is authorized solely to execute heading changes.
  • Climb/Descend: The receiving controller is permitted only to adjust the aircraft’s altitude, either climbing or descending.

Any applicable restrictions or transfer conditions must be clearly communicated and agreed upon during coordination. If the receiving controller does not accept the aircraft tag within a reasonable timeframe, the transferring controller remains responsible for the aircraft until contact and transfer are completed.

3.6 Phraseology for Coordination

Effective and standardized phraseology is essential for clear, concise, and unambiguous communication between controllers during coordination, handover, and transfer of control. ICAO provides standardized phraseology to minimize misunderstandings and enhance safety.

Most coordination between sectors and adjacent FIRs is conducted electronically through the TopSky ATM system, enabling silent transfer of flight data such as position, altitude, and route. This reduces frequency congestion and controller workload by minimizing the need for voice coordination.

Voice communication and use of phraseology as per ICAO standards are required only when special coordination is necessary, such as for deviations, restrictions, emergencies, or any condition not reflected in the electronic system.