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Issuing PDC

Why do we issue PDCs?

Whenever suitable, controllers are encouraged to issue Pre-Departure Clearance (PDC) electronically to pilots so as to ensure minimal delay for pilots waiting to receive IFR clearance. Issuing PDCs reduces pilot errors in understanding the clearance, improves initial climb adherence and minimises RT (frequency) loading.

In the real world, most major airports use datalink clearances to electronically clear aircraft. This should be used as much as possible on VATSIM to aid both realism and efficiency.

Methods of issuing PDC

The VATSIM implementation of PDC is currently available via the 🔗 Hoppie network and can be used through various EuroScope plugins. vSMR is included with the pack and set up by default. Other options, such as 🔗 vEFPS, allow for more advanced PDC functionality, e.g. automated responses where appropriate.

Controllers are encouraged to use one form of 🔗 Hoppie implementation to cater for pilots who use it, and when it is in operation, it should be advertised as such in the controller’s logon ATIS. E.g.: PDC ATIS Example

When pilots request clearance via voice, assuming no changes to flight plan are required, a datalink PDC can be emulated by sending a direct message PDC, using the .pdc Text Alias with the aircraft selected. This will expand automatically to a .msg message which can be sent from the EuroScope message bar. A short courtesy response on RT may be used to alert the pilot to the fact they will receive a text message with their clearance, e.g.:

Radiotelephony

BVX240A, roger, text PDC sent.

Between the use of Hoppie and .pdc, lots of time can be saved and few aircraft should be left waiting for clearance for more than a few seconds. There will of course be some exceptions, such as those who require flight plan changes or are not departing via a SID, but the saving on RT time should make these easier to deal with too! We encourage you to use these tools at all levels of controlling, from EGxx_DEL up.

When to use PDC

General Guidance

Controllers are encouraged to provide a PDC service at any UK aerodrome that has SID departures.

VATSIMism

In reality, only major airports have datalink clearance capability. Local ATC documentation will indicate whether PDC services are available at an aerodrome in the real world.

PDC clearances shall not be issued in the following circumstances:

  • For any departure route other than a SID.

Note

PDC is unable to provide clearances on non-SID routes - this include routes that might otherwise be considered a “standard departure”. Controllers must also ensure that aircraft on non-standard routes (for example positioning flights) are provided an appropriate clearance and that issuing a PDC does not lead to a failure to perform mandatory coordination.

  • When the route of an aircraft’s flight plan needs to be changed, or for expedition during a flow restriction on a particular routing.
  • Up to half an hour before a runway change, to prevent the incorrect issuing of a SID. The actual availability of PDC will be at the GMP controller’s discretion

Note

Should the controller elect to continue issuing PDC clearances within the 30-minute period before a runway change they shall only issue manual PDC clearances and deactivate their system's automatic PDC feature (if present). This is to prevent the inadvertent issue of an PDC clearance with an incorrect SID without the controller noticing.

In all the above cases, the pilot should be advised by ACARS message to call the controller handling clearances by voice in order to obtain ATC clearance.

Automatic PDC Guidance

Automatic PDC provides fully automatic replies to aircraft requesting PDC clearances. Typically, the tools that deliver this function provide three types of response, configurable on a per-SID basis:

  1. Refuse - Pilots will receive an automatic "Revert to Voice" ACARS message.
  2. Manual - Requires the controller to review and approve each PDC request.
  3. Automatic - PDC is issued without any controller interaction.

Warning

Automatic PDC must be used with caution.

Whilst Automatic PDC can significantly reduce controller workload, the issuance of a valid Automatic PDC requires that the Euroscope Cleared Level and Assigned SSR Code fields are correct prior to the aircraft requesting PDC. As such, when using Automatic PDC controllers should set UKCP to automatically allocate initial cleared levels and SSR codes.

Controllers must also note that Automatic PDC may lead to a clearance being issued on an inappropriate route - see the guidance below. Controllers must still check the route of aircraft on first contact when they indicate they have received a PDC.

Automatic PDC should not be used with:

  • SIDs which have been withdrawn (i.e. Out-of-date procedures).
  • Relief SIDs.
  • SIDs not in use due to runway-in-use.
  • SIDs not in use due to alternative special procedures being adopted (e.g. Heathrow (EGLL) CPT departures off Runway 09L/R).

Warning

Additionally, care should be taken if using Automatic PDC to issue any required warnings verbally on first contact with the aircraft. For example on SIDs which feature a step-climb out of Luton (EGGW).

Using vSMR for PDC

First time set-up

The vSMR plugin is included with the 🔗 UK Controller Pack. Using the LogonDetails.exe script to set up your pack allows you to place your Hoppie Code (obtained via the 🔗 Hoppie website) into all profiles. Otherwise, in the message bar in EuroScope, type .smr, press Enter. You will be met with the dialog shown where you can insert your code and press OK.

vSMR Setup Dialog

Everything else should be configured through the pack already.

Connecting to Hoppie

To begin using Hoppie, run the command .smr connect in the EuroScope message bar. You should get a message back from "CPDLC" like this:

vSMR Logon Message

Responding to a PDC Request

When a pilot requests clearance via Hoppie, the DCL column for that aircraft will flash with an R, and a ping will sound if you have that option enabled:

vSMR flashing R

Click the R and a Datalink menu will open:

vSMR Datalink Menu

To send the PDC, select Confirm, which opens the clearance dialog shown below. If for some reason you need the aircraft to revert to voice for clearance, you can click Voice.

vSMR Clearance Dialog

Once you've checked the details in the clearance dialog are correct, click Send to send the PDC. The dialog will close and the R will change to a yellow V: vSMR Yellow V

When the clearance is acknowledged by the pilot, the V will turn green, and you can click the clearance flag: vSMR Green V

Troubleshooting

If a pilot reports that they have requested PDC, but you haven't received a flashing R, you can check the Hoppie Message Log for the airport you're controlling, e.g. 🔗 http://hoppie.nl/acars/system/callsign.html?network=VATSIM&callsign=EGCC for Manchester (change the ICAO at the end of the link for different airports).

Some common causes of issues are the pilot mis-typing their callsign or departure airport ICAO code, or failed to file a flight plan at all (in which case you may hear the ping but not have an R flash up).