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A-CDM

Airport Collaborative Decision Making (A-CDM) Controller Guide

What is A-CDM?

A-CDM is a tool that encourages virtual pilots, controllers, and dispatchers to coordinate more effectively in an online flight simulation environment. By sharing essential departure data, planning collaborative push-back times, and adhering to consistent procedures, A-CDM helps to reduce airfield congestion and improve overall traffic flow. The result is a more immersive, realistic, and seamless experience for everyone involved in the virtual aviation community.

A-CDM can be used by controllers at any time they deem necessary. At certain events, the use of A-CDM may be notified as mandatory. As a general rule, if opening a PLN position at a busy airfield, it is advised to enable the system.

Timings

There are several key timings associated with an aircraft's departure:

Time Description
EOBT Departure time entered by the pilot on the flight plan (not typically useful for online networks as it is often inaccurate).
TOBT The time the aircraft aims to push back.
TSAT The time ATC plans to approve start, considering flow restrictions, taxi times, capacity, etc.
ASRT The time at which the pilot requests start-up.
TTOT The estimated time the aircraft will be airborne.
CTOT Also known as a "slot," the aircraft must depart within -5/+10 minutes of this time.

Enabling The Plugin

The plugin is pre-configured in the controller pack for all SMR profiles. Each airfield must have a master controller, with other controllers at the same airfield acting as slaves. Normally, the controller providing the PLN (or Planner when rostered) function will be the master.

  • .cdm master {airport} enables you as the master for the airfield.
  • .cdm slave {airport} allows you to receive A-CDM data for the airfield.

Warning: Only the master controller at an airfield will be able to edit the A-CDM times.

Controller Handover

During a controller handover, the existing master should use the command .cdm slave {airport}, followed by the incoming controller using .cdm master {airport}.

A-CDM Colours

TOBT Colour Codes
Colour Definition
#8fd894 (LIGHT GREEN) Before TOBT -5
#00c000 (DARK GREEN) TOBT -5 → -2
#f5ef0d (YELLOW) Last minute of TOBT
TSAT Colour Codes
Colour Definition
#8fd894 (LIGHT GREEN) TOBT -35 to TSAT -5
#00c000 (DARK GREEN) TSAT -5 to TSAT +5
#f5ef0d (YELLOW) From TSAT +5 to TSAT +6
#be0000 (RED) TSAT >+6 (Expired)
CTOT/TTOT Colour Codes
Colour Definition
#00c000 (GREEN) CDM Server CTOT
#d4852e (ORANGE) Manual/Event CTOT
#be0000 (RED) Flow/CAD CTOT

Controller Responsibilities

PLN / Planner

Slotted Events

For events with CTOTs, these will be added to the system before the event. This is linked to the pilots' CID.

  • When a pilot with an event booking logs in, the system will automatically show the event CTOT in the EVNT column.
  • The PLN controller (or Planner when rostered) must left-click on the event CTOT to generate the A-CDM times as soon as the aircraft appears in the departure list.
  • When the pilot calls for clearance, PLN shall advise the aircraft of the TSAT.

Example Phraseology

  • ATLAS123, cleared to Tunis, MOGTA2D departure, Squawk 3241, QNH 1017. Expect start at time 1345.
  • ATLAS123, contact Algiers Planning on 128.875 when ready.

Pilots without a slot or those who miss their TSAT by more than 5 minutes should be handled accordingly.

Note: When a dedicated Planner position is rostered, the PLN (Clearance Delivery) controller’s primary responsibility is to validate routes and issue clearances.

Non-Slotted/Overload Events
  • When the aircraft calls ready for start, PLN (or Planner when rostered) will left-click the TOBT & ASRT columns to generate the A-CDM system times.
  • If the TSAT is within +/-5 minutes (dark green), the aircraft can be passed to GND for start-up.
  • If the TSAT is not within +/-5 minutes (light green), the aircraft must be advised of the TSAT and instructed to hold position.

Note: When passing a pilot to GND for start-up, PLN (or Planner when rostered) should mark the status flag in the departure list as "STUP".

GND Responsibilities

  • Once an aircraft calls fully ready, the GND controller must check the TSAT.
  • If the TSAT is within +/-5 minutes, start-up clearance can be issued.
  • The TTOT/CTOT columns in the taxi-out list should be used to determine a reasonable departure sequencing order.
  • Final sequencing for departure remains the responsibility of the TWR controller.

TWR Responsibilities

  • The TWR controller should use TTOT/CTOT fields to determine departure order while ensuring normal route/speed/wake separation.
  • CTOTs should be prioritized to comply with flow restrictions such as MDIs.

Video Guide

A video guide on A-CDM is available to assist controllers in understanding the plugin and its functions: Watch Here.

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