Coordination
Coordination helps controllers stay aware of aircraft that are about to enter their jurisdiction and ensure they will operate in a predictable manner, which allows for easier planning of sequencing and separation.
Coordination requirements are often very location-specific, however this page outlines the general guidelines to coordination, which are supplemented by Local Instructions.
MATS Chapter 6 goes in to much more detail about coordination principles, phraseology, and situations. It is well above the level required for VATSIM, but feel free to read up on it if you want to extend your learning.
Coordination in vatSys
Coordination is performed using the VSCS window in vatSys. Once logged onto a relevant position, controllers have the option of opening hotlines and coldlines to surrounding positions.
A hotline is opened by pressing the yellow button titled with the sector you wish to communicate with, which creates an instant connection between positions with no need for the other controller to accept the call. A coldline is opened by pressing the blue button titled with the sector you wish to communicate with, which notifies the other position and requires them to accept the call before communications can begin.
Tip
For more in depth information, refer to the vatSys website.
Coordination notes are included for most positions, using the following format:
Hotline: ORIGINATING SECTOR -> RECEIVING SECTOR: "Message"
Coldline: ORIGINATING SECTOR -> RECEIVING SECTOR: "Message"
General Phraseology
As a receiving controller, answer a coordination call by stating the name of your position.
Phraseology
GUN calls SAS with a hotline to discuss an arrival
GUN -> SAS: *DING*
SAS -> GUN: "Sydney Approach"
GUN -> SAS: "Via RIVET, QFA541, request heading 030 due weather"
SAS -> GUN: "QFA541, Concur heading 030"
If you are busy at the time, tell the other controller to standby. If you anticipate a long delay, tell the controller that you'll call them back.
Phraseology
ELW calls MAE with a hotline but MAE is awaiting a readback from an aircraft
ELW -> MAE: *DING*
MAE -> ELW: "Standby"
When MAE is ready
MAE -> ELW: "Go ahead, Centre"
Each controller must verbalise the instruction, clearance, or change once. Generally, with one controller requesting a change, the approving controller will confirm it, completing the conversation.
Phraseology
ELW -> MAE: "Via BOOIN, JST414, assigned FL120 for my separation with VOZ92"
MAE -> ELW: "FL120, JST414"
In situations where additional changes have been discussed (and as such, both controllers have not yet verbalised them), a readback is required.
Phraseology
CS ADC -> CS TCU: "Next, LKU, runway 15"
CS TCU -> CS ADC: "LKU, runway 15, left turn, unrestricted"
CS ADC -> CS TCU: "Left turn, LKU"
Point-to-Point
Coordination must be done on a point-to-point basis, meaning you can only coordinate with the sector adjacent to yours which the aircraft is coming from, or going to, no skipping! The exception to the rule is onwards coordination, where a controller assumes responsibility for coordinating with other stations.
Example
You are controlling ELW and you would like to suggest an amended route to someone on the ground at YMML. Whilst that may be no issue for ML SMC and ML ADC, it might not work for ML APP. ML APP would be the sector which the aircraft is coming from, so ELW must talk to them, and it is the responsibility of ML APP to work backwards down the line on a point-to-point basis.
Ensure no coordination is ambiguous in its meaning. While proper phraseology is strongly encouraged, plain English may be used where there is no ambiguity and the message is fully understood by both parties.
Onwards Coordination
Onwards coordination is a practice by which a controller will assume another controller's responsibility for coordination and coordinate on their behalf, reducing the downstream controller's workload.
This is most useful when controllers are coordinating to multiple lateral positions, or where the controller "in the middle" of the chain of coordination has no frequency requirements.
Example
You are controlling MAV and an aircraft departing YMAV via ML to the northwest has requested direct to a waypoint in MDN's airspace.
Ordinarily, you would be responsible for coordination with MDS, while MDS is responsible for coordination with MDN. With onwards coordination, you can coordinate with MDN on MDS's behalf.
Phraseology
MAV -> MDS: "East of AV, JST626, request direct DOTPA. My onwards with MDN"
MDS -> MAV: "JST626, direct DOTPA, your onwards with MDN."
MAV -> MDN: "East of AV, JST626, request direct DOTPA"
MDN -> MAV: "JST626, direct DOTPA"
A controller can either offer to assume responsibility for onwards coordination, or be given the responsibility by another controller.
Tip
If another controller is offering to perform onwards coordination on your behalf, you're not obliged to accept. If you identify that you have other requirements, or would prefer to perform the coordination yourself, decline the offer: "I will coordinate with..."
Types of Coordination
As a general rule, some form of coordination is required prior to every handoff. In the majority of cases, this will be voiceless coordination. Local procedures dictate the coordination requirements between each position.
Voiceless
Voiceless coordination permits the handoff of an aircraft without prior voice coordination, provided certain criteria are met. These rules are specified on each position's SOPs page and generally involve having aircraft track via certain routes and/or levels.
These routes may also have change parameters, where no changes are permitted within a certain distance of the sector boundary without prior coordination. If a change is required to be made inside these threshold distances, or if voiceless coordination is not available for an aircraft's intended flightpath, voice communication must take place.
Example
Heads-up
Heads-up Coordination is the act of giving the next sector a "heads-up" about an aircraft about to enter their airspace, and should be performed for all handoffs which don't meet the criteria for voiceless coordination.
The format is as follows:
Controlling Sector -> Receiving Sector: "(Position), (Callsign)"
Receiving Sector -> Controlling Sector: "(Callsign), (Level)"
Phraseology
BLA -> GUN: "via CB, VOZ1234"
GUN -> BLA: "VOZ1234, F350"
If the level that will be assigned at transfer of jurisdiction is different from the current CFL, the Controlling Sector will use the phrase "will be assigned (level)".
If the Receiving Sector requires a change of level, they'll reply with the amended level.
Example
Phraseology
WOL -> GUN: "Via CB, RXA32"
GUN -> WOL: "RXA32, F340 due traffic"
WOL -> GUN: "F340, RXA32"
Once this coordination is completed, the aircraft's level and route is locked in. Any further changes must be recoordinated.
Tip
In situations where Heads-Up Coordination is required, the best time to do it is when the aircraft first calls you. There's no need to wait until half a mile before when its due, if you can get it done sooner.
Boundary
Boundary coordination is required when an aircraft may deviate within half the applicable standard of another sector's airspace.
Ie: within:
- 500ft vertically; or
- 2.5nm laterally for ENR; or
- 1.5nm laterally for TCU/ADC
Boundary coordination must be completed so they are aware of the aircraft, and can nominate any restrictions.
The format is as follows:
Controlling Sector -> Boundary Sector: "For Ident, (Position), (Callsign), (Details as required)"
Boundary Sector -> Controlling Sector: "(Callsign), (Restriction)"
Example
Phraseology
GUN -> WOL: "For Ident, northeast of CB, QFA494, do you have any restrictions on descent?"
WOL -> GUN: "QFA494, no restrictions on descent"
The Boundary Sector may omit the restriction and readback the callsign only. This will be taken as the Boundary Sector having no vertical or lateral restrictions.
Phraseology
INL -> BAS: "For Ident, west of BLAKA, FD516"
BAS -> INL: "FD516"
Next
Next coordination is performed between ADC and TCU controllers to discuss the next aircraft to depart. As a general rule, all departing aircraft require Next coordination, unless stipulated by local SOPs through the use of Auto Release. Auto Release can be cancelled at any time through mutual agreement of the ADC and TCU controllers.
The format is as follows:
ADC -> TCU: "Next, (Callsign), (Runway)"
TCU -> ADC: "(Callsign), (Runway), (Lateral and/or Vertical Instructions)"
Example
Phraseology
AD ADC -> AD TCU: "Next, RXA4376, runway 23"
AD TCU -> AD ADC: "RXA4376, runway 23, right heading 290, unrestricted"
AD ADC -> AD TCU: "Right heading 290, RXA4376"
Aircraft assigned a procedural SID will generally not be issued with lateral instructions. Aircraft assigned a radar SID or visual departure must be provided with an assigned heading or other lateral departure instructions, with examples shown below:
| Instruction | Meaning |
|---|---|
| Left/right turn | Make a visual left/right turn to establish on the planned outbound track |
| Left heading 180 | At the SID turn height, or at a safe altitude (if visual departure), fly heading 180 |
| Left heading 180 visual | As above, but with a pilot requirement to maintain visual separation with the ground/water and any obstacles |
| Extended runway centreline | Track the extended runway centreline (accounting for drift) |
An amended level may be instructed, or the term unrestricted used to indicate that no additional vertical restrictions apply. This permits the aircraft to climb to their cleared level (as issued with their airways clearance).
Note
The term 'unrestricted' is not a readback item.
Phraseology
LKU is conducting a visual departure from YBCS
CS ADC -> CS TCU: "Next, LKU, runway 15"
CS TCU -> CS ADC: "LKU, runway 15, left turn, unrestricted"
CS ADC -> CS TCU: "Left turn, LKU"
QFA442 is assigned a procedural SID from YMML with Auto Release cancelled
ML ADC -> ML TCU: "Next, QFA442, runway 16"
ML TCU -> ML ADC: "QFA442, unrestricted"
After a go around
Following a go around, the next departure from that runway must be next coordinated between the ADC and TCU controllers, regardless if it would otherwise meet the auto release criteria.
Airways Clearance
The local procedures of some aerodromes require ACD to coordinate with the TCU prior to issuing airways clearance to certain aircraft. This coordination allows the TCU controller to assess the current & projected traffic levels, and current position staffing, and determine whether clearance is available.
The format is as follows:
ACD -> TCU: "(Callsign) requests clearance to (Destination), (Any Other Relevant Details)"
TCU -> ACD: "(Callsign), clearance approved"
Phraseology
SY ACD -> SY TCU: "LKU, VFR aircraft, requests clearance to Bankstown"
SY TCU -> SY ACD: "LKU, clearance approved"
Example
If a change of level or tracking is required, the TCU controller shall provide this change during this exchange.
Intra-Tower Coordination
Runway Crossings
When coordinating with Tower, there are three key items that must be used.
- Aircraft Type: A320, B737, B777, C172, etc;
- Location: Taxiway the aircraft is currently on;
- Runway: The runway the aircraft will enter, backtrack or cross.
The format is as follows:
SMC -> ADC: "(Aircraft Type) on (Location) to cross (Runway)."
ADC -> SMC: "(Aircraft Type) on (Location) cross (Runway)."
or
ADC -> SMC: "Negative. Hold Short."
SMC -> ADC: "Hold Short (Runway)."
Tip
SMC can expedite the coordination process by applying the crossing highlight to an aircraft's strip in OzStrips and placing it in the Holding Point Bay.
This will indicate the need to facilitate a runway crossing to ADC and may prompt them to proactively hotline SMC to approve the crossing when a suitable gap in the sequence exists.
Approved runway crossings should be recorded in OzStrips.
Runway Releases
As an alternative to coordinating individual aircraft crossings, ADC may 'release' a non-active runway to SMC. This reduces the workload of both controllers by allowing SMC to instruct aircraft to cross or otherwise use the non-active runway without coordination.
Phraseology
CB SMC -> CB ADC: "Request Runway 30 release to Ground"
CB ADC -> CB SMC: "Runway 30 released to Ground"
Coordinated runway releases should be recorded in OzStrips.
Recalling a Runway
ADC can recall a runway release immediately. Upon recall, SMC shall acknowledge the recall with a traffic statement.
Phraseology
AD ADC -> AD SMC: "Cancel release of Runway 30"
AD SMC -> AD ADC: "Runway 30, no traffic"
or
AD SMC -> AD ADC: "Runway 30, traffic is a B737 crossing on F."
Helicopter Movements in SMC Jurisdiction
ADC must coordinate with the relevant SMC controller before permitting an helicopter to take off or land on any part of the manouevring area under the jurisdiction of ADC.
This ensures SMC will keep the designated are clear from taxiing traffic.
Phraseology
PH ADC -> PH SMC: "Helicopter YOE inbound for landing on Taxiway C9."
PH SMC -> PH ADC: "YOE."
Helicopter Air Transit
A helicopter performing an air transit maneouvre must be coordinated from SMC to ADC.
Phraseology
BRM SMC -> BRM ADC: "Robinson 44 on Eastern Heli Parking, for air transit to Western Helipad"
BRM ADC -> BRM SMC: "Air transit approved."
The C-Prompt (Coordination Prompt)
Display the "C-Prompt" when all coordination for an aircraft is complete, or voice coordination is not required for an aircraft (ie. subject to voiceless coordination).
The "C-Prompt" can be displayed by middle clicking the area just above the aircraft's callsign in the label.
Remove the "C-Prompt" once jurisdiction of the aircraft has been handed off, and the new frequency has been correctly read back.
No Frequency Requirements (NFR)
Some aircraft may clip small parts of a sector's airspace on their cleared route. If an aircraft only enters someone's airspace for a small distance, there is usually no need for them to talk to that controller.
In this instance, a controller may coordinate any:
- Frequency Requirements: requirement for the pilot to be switched to the second controller's frequency
- Restrictions: limitations which the second controller imposes to maintain separation assurance with aircraft in their sector
| Label Data / Global Ops | Meaning | Note |
|---|---|---|
| NFR | No Frequency Requirements | Additional coordination must be done for any lateral or level changes |
| NR | No Restrictions | Any and all lateral and level changes approved |
| NRR | No Restrictions or Requirements | Any and all lateral and level changes approved, and No Frequency Requirements |
| NRD | No Restrictions on Descent | Additional coordination must be done for any lateral changes |
| NRC | No Restrictions on Climb | Additional coordination must be done for any lateral changes |
| NVR | No Vertical Restrictions | Additional coordination must be done for any lateral changes |
| NLR | No Lateral Restrictions | Additional coordination must be done for any level changes |
Tip
See Annotations for a complete list of label annotations.
Offering your Airspace
As you scan your Announced Bay and the airspace surrounding your sector, you may notice aircraft who will only clip a small portion of your airspace.
Provided you do not have any potential conflicts with the aircraft, it is good practice to coordinate with the upline controller to offer NFR. This reduces the number of frequency transfers required by the pilot.
Example
Phraseology
VOZ1392 is tracking direct to YWLM
ARL -> INL: "West of CFS, VOZ1392, I have no vertical restrictions or frequency requirements, your onwards with MNN"
INL -> ARL: "VOZ1392, my onwards with MNN"
INL will put "ARL NVR NFR" in the label data
INL -> MNN: "West of CFS, VOZ1392, ARL has no vertical restrictions or frequency requirements"
MNN -> INL: "VOZ1392"
INL will handoff the aircraft directly to MNN
Suggesting Adjacent Airspace
An aircraft under your jurisdiction may clip another controller's airspace (either to return to your jurisdiction or when transiting to a third controller).
Controllers should perform heads-up coordination and optionally, offer NFR. Where the pilot will transit to a third controller, it is important that onwards coordination takes place to that controller.
Example
Phraseology
VOZ1447 is tracking direct to CWR
MUN -> ASP: "Northeast of MIA, VOZ1447, do you have any restrictions or requirements?"
ASP -> MUN: "VOZ1447, I have no restrictions or requirements"
MUN will put "ASP NRR" in the label data
Handoffs
Receiving a handoff means you are permitted to turn an aircraft 45 degrees left or right, and climb/descend it to any level without coordination. Do not handoff an aircraft to another sector if a turn of 45 degrees or a change of level would cause a conflict with any of your own aircraft. Alternatively, you can nominate a restriction prior to handoff.
A restriction can be limited to vertical or lateral, or be limited by a single aircraft. In this case, nominate the conflicting aircraft themselves as the restriction.
Example
Phraseology
BLA -> GUN: "QFA501, my restriction is QFA494"
GUN -> BLA: "QFA501, restriction is QFA494"
When an aircraft is nominated as a restriction, both controllers are jointly responsible for maintaining separation assurance. Any flightpath deviations which may impact separation assurance must first be backwards coordinated between the controllers.
Upon receipt of a handoff, once the aircraft is established half the applicable lateral standard (2.5nm for ENR, 1.5nm for ADC/TCU) within your airspace, you are free to turn the aircraft as much as you like. If you need to turn them more than 45 degrees earlier than that, simply ask!
Phraseology
KPL -> RKA: "ZYX, do you have any restrictions?"
RKA -> KPL: "ZYX, no restrictions"
KPL will place "RKA NR" in the label until 2.5nm clear of their airspace, to record that the coordination has been completed.
For more information, refer to individual local instructions.
Rules
Class D Towers
ENR/TCU -> Class D TWR
Heads-up coordinate arrivals/overfliers prior to 5 mins from the boundary.
"Via (Route/Procedure), (Callsign), (Level - if not standard assignable), (Runway - if not duty runway)"
Class D TWR -> ENR/TCU
Next call within 2 minutes of takeoff for all CTA departures.
Radar Towers
Radar TWR -> TCU
Next call within 2 minutes of takeoff unless overridden by local Auto Release rules.
If Auto Release is suspended by the TCU controller, respond by advising of any aircraft with a takeoff clearance.
Phraseology
TCU -> ADC: "Cancel Auto Release"
ADC -> TCU: "Cancel Auto Release, QLK108D released"
TCU -> ADC: "QLK108D"
TCUs
ENR -> TCU
Voiceless for aircraft landing at main airport (eg YMML in ML TCU), assigned a STAR, and standard assignable level, unless overridden by local procedure.
Heads-up coordinate all other aircraft by 20nm to boundary.
TCU -> ENR
Voiceless for aircraft assigned lower of standard assignable level or RFL, and tracking via a Procedural SID terminus, unless overridden by local procedure.
Note
Aircraft are not required to be tracking via the SID procedure, simply tracking via any of the terminus waypoints (regardless of departure airport or assigned SID) is sufficient to meet the criteria for voiceless coordination.
Heads-up coordinate all other aircraft by the boundary.
Radar Position -> TCU Controllers
Entering CTA
Heads-up coordination is required for all aircraft entering TCU CTA from Class G. Heads-up coordination must be completed prior to handoff, however, best practice is to complete the coordination as soon as possible.
Upon receipt of the heads-up coordination from Radar, the TCU controller has several options:
| Response | Use Case |
|---|---|
| Acknowledge the callsign | Indicate to Radar that you can accept the handoff to provide clearance |
| "Remain outside Class C airspace, expect XX minute delay" | Useful if it's busy |
| "Clearance unavailable due XXXX" | Useful if the pilot's request is unlikely to be available at all |
| "I'll call you back" | Useful if the TCU controller hasn't had time to assess the aircraft yet (remember to cock the strip) |
Phraseology
SYC -> SDS: "Departed YSHL, EQU"
SDS -> SYC: "EQU"
SYC: "EQU, Contact Sydney Departures on 129.7 for clearance"
EQU: "129.7, EQU"
...
EQU: "Sydney Departures, EQU, climbing to F170"
SDS: "EQU, Sydney Departures. Cleared to YWLM via TESAT, flight planned route. Climb to F170"
EQU: "Cleared to YWLM via TESAT, flight planned route. Climb to F170, EQU"
Phraseology
SYC -> SDS: "Departed YSHL, EQU"
SDS -> SYC: "EQU remain outside Class C airspace, expect 10 minute delay."
SYC -> SDS: "Remain outside Class C airspace, expect 10 minute delay, EQU."
SYC: "EQU, remain outside Class C airspace, expect 10 minute delay."
EQU: "Remain outside Class C airspace, copy, EQU"
SDS -> SYC: "EQU to contact me."
SYC -> SDS: "EQU to contact you."
SYC: "EQU, Contact Sydney Departures on 129.7"
EQU: "129.7, EQU"
...
EQU: "Sydney Departures, EQU, climbing to F170."
SDS: "EQU, Sydney Departures. Cleared to YWLM via TESAT, flight planned route. Climb to F170"
EQU: "Cleared to YWLM via TESAT, flight planned route. Climb to F170, EQU"
At locations with a low overlying base of CTA (e.g. YSBK with the tower closed), Radar shall perform normal coordination to the appropriate CTA controller in response to a taxi call. It is expected that Radar will transfer the aircraft to the CTA controller to issue clearance prior to the aircraft's departure.
Leaving CTA
Heads-up coordination is not required from a TCU position to Radar for aircraft:
- Assigned 500ft above the BCTA as the CFL; and
- Handed off to Radar
Phraseology
FD214 is intending on leaving Class C airspace on descent into Bankstown. The lower limit of CTA is A045.
SDS: "FD214 descend to A050, contact Sydney Centre 124.55"
FD214: "Descend A050, 124.55, FD214"
FD214: "Sydney Centre, FD214, descending A050"
SYC: "FD214, Sydney Centre, leave controlled airspace descending, no reported IFR traffic"
FD214: "Leave controlled airspace descending, FD214"
Heads-up coordination is not required from a TCU position to Radar for aircraft:
- Handed off to Radar upon termination of control services
Phraseology
CYF is an IFR C172 leaving CTA to the north at A050.
SAN: "CYF at 30DME SY, control service terminates, contact Sydney Centre 124.55"
CYF: "124.55, CYF"
CYF: "Sydney Centre, CYF, maintaining A050"
SYC: "CYF, Sydney Centre, no reported IFR traffic, area QNH 1024"
Enroute
ENR -> ENR
Voiceless, no changes to route or CFL within 50nm of the boundary, unless overridden by local procedure.
To/from Oceanic/International Units
Pacific Units
For aircraft going between the following FIRs in Oceanic Airspace only:
- YBBB
- YMMM
- NFFF
- NFFJ
- AGGG
- ANAU
- NZZO
- NZCM
- KZAK
- NTTT
- AYPM
Voiceless, no changes to route or CFL within 15 mins of boundary.
Other Units
For aircraft going to the following FIRs:
- WAAF
- WIIF
- VCCF
- VRMF
- FIMM
- FAJO
Heads-up coordinate prior to 30 mins to boundary.
Voice coordination to International units shall be done in the following format:
"Estimate, (Callsign), (Boundary Point) (Estimate), (Level), on climb/descent if applicable"
Phraseology
IND -> FIMM CTR: "Estimate, QFA63, IBMAT time 33, F360"
FIMM CTR -> IND: "QFA63, F360"
OCTA Coordination
For any aircraft transiting to or from uncontrolled airspace (ie: Class G, VFR Class E), heads-up coordination is not required. However, a 5 minute change parameter applies to any aircraft that change level, route, or taxi within 5 minutes of the next sector's airspace.