2021-02-05 - Clarification on the Use of the Aerodrome Traffic Monitor (ATM)

[VATSIM UK Operations]

Effective 05 February 2021

On VATSIM, aerodrome controllers do not work from a visual control room (VCR) and are limited to the use of the ATM to provide air traffic control services. Furthermore, pilots are not restricted by real weather conditions and may for instance operate VFR when real world conditions are IMC.

It is assumed that an ATM is available and utilisation of the advanced functions of the ATM is approved at all airfields in the UK. However, there is a difference between which of these functions are available to use by S2 and S3+ rated controllers due to the differences in training that is provided by VATSIM UK for these ratings.

S2 rated controllers may use the ATM to: 

• Provide functions that would normally be facilitated using a VCR;
  • Note: During periods of IMC, controllers should adopt appropriate procedures, but should not prevent aircraft wishing to operate VFR from doing so. In this case, controllers should continue to provide control to these specific aircraft as if they were in VMC. In this instance, if a VFR aircraft in IMC is required to comply with a conditional clearance that is dependent on having another aircraft in sight, they should be asked to confirm that they have the aircraft in sight prior to the conditional clearance being issued. (e.g. An aircraft in the visual circuit is required to report final behind landing instrument traffic. They should first be instructed to report the instrument traffic in sight.)
• Determine the landing order, spacing and distance from touchdown of arriving aircraft;
  • Note: this function is primarily for the purpose of planning departures - it is not the AIR controller’s responsibility to provide wake vortex arrival separation to aircraft conducting an instrument approach.
• Assist in applying longitudinal separation for departing aircraft;
  • Note: this includes 4NM heavy:heavy wake turbulence separation and, where approved, 5NM in lieu of 2 minute departure interval separation.
• Enable the controller to confirm that the initial track of a departing aircraft conforms with the clearance issued;
• Provide information to aircraft on the position of other aircraft in the circuit or carrying out an instrument approach.

Note: S2-rated controllers are only permitted to apply reduced separation in the vicinity of the aerodrome (RSIVA) to reduce departure separation at London Heathrow (EGLL).

What does this mean practically for S2 controllers?

• Missed approaches - instruct aircraft to "fly the standard missed approach", unless radar issues different instructions to establish separation. Don't apply different headings or levels yourself other than in extreme circumstances.
• Don't assume or "pick up" tags of aircraft - this tells other controllers that you have IVV'd the aircraft which is not covered in our S2 training. Do however, check that the aircraft is squawking Mode C before transferring them to the area departures controller. Read more about this here.
• Always use time based (normally 1, 2 or 3 minutes) route separation minima for departures unless you are at Heathrow (and are trained to use RSIVA) or are applying 5NM instead of 2 minutes (note that this can only be done at certain airfields - read the vMATS!)

You can read more into this topic on the VATSIM UK S2 Moodle Course

 

Utilisation of the advanced functions of the ATM requires further training. S3+ rated controllers may, when operating a tower position (inc. top-down) at any airfield, utilise the ATM to:

• Utilise RSIVA in order to reduce departure separation minima where local procedures allow and in appropriate weather conditions;
• Following identification, validate SSR codes of departing aircraft and verify associated Mode C read-outs;
• Monitor the progress of overflying aircraft identified by Approach Radar Control to ensure that they do not conflict with the tracks of arriving or departing aircraft;
• Establish separation between departing aircraft 
  • Note: S2 rated controllers may utilise this function ONLY at Heathrow.
• Pass traffic information;
• Establish separation in the event of a missed approach;
• Assist in taking initial corrective action when the separation between arriving aircraft becomes less than the prescribed minima
   

What does this mean practically for S3 controllers?

• Generally - operate tower positions in the same manner that you would expect an S2 controller to.
• Missed approaches - stick to the standard missed approach unless radar issues different instructions to establish separation. You can apply headings and levels to establish separation if you cannot coordinate with radar, but make sure that this will not cause conflicts with other aircraft and make sure to coordinate what you have done with radar afterwards.
• Unless a situation develops where you have IVV'd the aircraft, don't assume or "pick up" tags of aircraft as a tower controller. Do not complete IVV for departures that do not require it and do not delay handoffs to the area departures controller, only check that the aircraft is squawking Mode C. Read more about this here.
• Generally, use time based (normally 1, 2 or 3 minutes) route separation minima for departures unless local procedures allow that to be reduced by other means.

Edited February 5, 2021 by Jack Edwards