Expanded CDM Procedures (TWR/GND/DEL)
Before you start, make sure CDM is started for your airport. See Starting CDM Only& one controller per airport can be CDM master, and only the master calculates TSATs. The master shall be the lowest online position at that airport (DEL > GND > TWR > APP/CTR top-down). All other controllers are slaves by default and do not need to do anything.
If you are the lowest position at an airport, write .cdm master ICAO (e.g. .cdm master BIKF) for each airport you cover.
Handinghanding over master
When a lower position logs on, or the current master logs off, master must be handed over:
The old master switches to slave by writing.cdm slaveOnce there is no master, the new controller takes over by writing.cdm master ICAO
Never have two masters for the same airport. Coordinate the handover before typing the command.
Expanded CDM Procedures (TWR/GND/DEL)
This covers both ATFCM (CTOTs) and A-CDM (TSATs).
Expanded CDM procedures are done from the start-up list. TWR may use the departure list instead. Please note that:
- You should follow A-CDM procedures unless traffic is low, using either the departure list or the start-up list.
- You MUST adhere to the displayed CTOT for take-off.
Reference Material
Click the TSAT column header. This sorts the list by TSAT and makes it easier to manage.
Expanded mode shows a lot more information, but the procedures are very similar.
Columns
There are four main times (EOBT, TOBT, TSAT, CTOT), three status columns (E, TTG, CONF) and four additional items (ASRT, ASAT, DE-ICE, ECFMP).
- EOBT: Estimated Off-Block Time
- The off-block time filed in the flight plan (e.g. from SimBrief). The time the passengers show up for.
- TOBT: Target Off-Block Time
- The time the aircraft expects to be ready, confirmed or updated by the pilot on the VDGS (vats.im/vdgs) or set by ATC.
- TSAT: Target Start-up Approval Time
- The time the system calculates from the TOBT to fit the aircraft into the departure sequence.
- Mainly for local airport capacity.
- CTOT: Calculated Take-Off Time
- The aircraft must take off within -5/+10 minutes of this time. The TSAT is adjusted to match.
- For external capacity (ATFCM, ECFMP).
| Colour | EOBT | TOBT | TSAT | CTOT |
|---|---|---|---|---|
| LIGHT GREEN | -- | Valid, but not yet active | -- | |
| DARK GREEN | -- | Active (within the start-up window) | Set by CDM server* | |
| YELLOW | -- | TOBT+4 to +5 (about to expire) | TSAT+4 to +5 (about to expire) | Default colour |
| RED | Flight suspended | -- | Set by CAD* | |
| ORANGE | EOBT more than 5 min from TOBT | Set by manual event* | ||
| WHITE | Default colour | -- | ||
*The source of a CTOT is for information only.
- E: Whether the TOBT is valid.
- TTG: Time to go until the TSAT (negative = time remaining, positive = past the TSAT).
- CONF: Whether the TOBT has been confirmed (or changed) by the pilot or by ATC.
| Colour | E | TTG | CONF |
|---|---|---|---|
| DARK GREEN | Correct (C) or Passed (P) | -35 min to +3 min | Default colour |
| YELLOW | -- | +4 min to +5 min | TSAT+4 |
| RED | Invalid (I) | -- | |
- ASRT: Actual Start-up Request Time
- The time the pilot requested start-up. Set it when a pilot calls before their TSAT window. It stops the flight being invalidated at TSAT and lets the system look for an earlier TSAT.
- ASAT: Actual Start-up Approval Time
- When start-up is approved (status set to STUP or PUSH), ASAT is recorded and the rest of the line turns grey.
- DE-ICE: De-icing assigned
- The aircraft needs de-icing, so the taxi-out time is extended.
- ECFMP: European Collaboration and Flow Management Project
- Shows where a flow measure comes from. For information only.
Procedures
The procedures depend on whether you are handling sequencing only, or both clearance delivery and sequencing.
Aircraft calls for ATC clearance (if within your area of responsibility)
If a CTOT is present: advise the pilot of the CTOT and of the earliest start-up time (TSAT).
If there is no CTOT: no further action is required at this stage.
Aircraft calls for start-up/pushback
Check the times:
- TSAT dark green: start-up can be approved.
- TSAT light green: the pilot is more than 5 minutes early and must wait.
- TSAT yellow: start-up can be approved, but be quick, as it is about to expire.
- TSAT blank: the flight has been invalidated and a new TOBT is needed (set by the pilot on the VDGS, or by you with Ready TOBT).
If the TSAT is light green, a CTOT is present, or the TOBT is invalid (expired), try to improve it with Ready TOBT (right-click the TOBT). This sets the TOBT to the current time and recalculates to look for an earlier TSAT.
If the TSAT is still light green after that, start-up cannot be approved yet:
- Click ASRT to record that the pilot has requested start-up.
- Approve start-up when the TSAT turns dark green.
When start-up is approved:
- Set the status to STUP or PUSH. This records the ASAT and greys out the rest of the times. The aircraft is released.
Flow Chart
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