Pre-departure clearance (PDC) is a system that provides instrument flight rules (IFR) departure clearances via data link to subscribing airlines at selected airports.

VATCAN PDC currently uses the private message (PM) communications protocol, with service currently limited to all VATSIM pilot clients.

Airports where PDC service is currently provided in the Toronto FIR are Toronto International, Toronto Island, London International, and Ottawa International. Expansion of the service to additional airports will be notified.

Current Operational PDC

Under the PDC protocol, air traffic control (ATC) sends a clearance without an electronic acknowledgement, thus requiring a verbal read-back of the Flight Plan Unique Identifier (FPUI). This is a fourcharacter (three numeric and one alphabetic) value generated by ATC and included in the PDC message. The FPUI is the primary element in the voice readback of the PDC clearance.

PDC – Procedures and System Messages

1. The pilot initiates PDC by sending a Departure Clearance Request (RCD). The RCD is sent by, filing your flight plan on VATSIM, and sending a request message via PM to the Delivery Controller or Controller assuming the position of Clearance Delivery. The message: “Departure clearance request.”

2. If the above condition is met the pilot will receive a Flight System Message (FSM) stating: RCD RECEIVED – REQUEST BEING PROCESSED – STANDBY.

3. Failure to submit an acceptable RDC will result in one of the following FSM being received: RCD REJECTED – FLIGHT PLAN INVALID – REVERT TO VOICE PROCEDURES; or RCD REJECTED – ERROR IN MESSAGE – REVERT TO VOICE PROCEDURES.

4. Once ATC receives a valid RCD, it will respond by sending the Departure Clearance Message (CLD).

5. At any time during the clearance process, if the pilot receives a FSM stating to REVERT TO VOICE the data link clearance becomes void and the pilot should contact ATC.

CLD EXAMPLE:

*PRE-DEPARTURE CLEARANCE* FLT ACA416 CYYZ – A320 FL330 XPRD 5514 – USE SID (DEDKI3) DEPARTURE RUNWAY (06L) DEST CYUL – DEDKI3 MIGLO HABBS3  . — CONTACT TORONTO DELIVERY ON FREQUENCY 121.30 WITHIN 10 MINS BEFORE *PUSHBACK* WITH ATIS, GATE NUMBER and *IDENTIFIER 501A* — END OF ACARS MESSAGE

This PDC message serves directly as your clearance. Once you received a PDC you will then need to contact delivery, and provide a read-back. If you do not receive a PDC, simply contact clearance delivery and request your clearance as normal. You will not need to ask for a PDC.

** Pilot Response **

Toronto Delivery, Air Canada 416, at gate 151 with information Bravo, Identifier 501A

It is best to file your flight plan as soon as possible so the controllers can get you your PDC as soon as possible. The process of issuing should be a fairly quick process, but if busy may take a few minutes. You will not want to file a flight plan and call for clearance 5 seconds later. That will not leave the flight data and clearance delivery controller enough time to process and prepare your flight plan information into a clearance.

These PDCs can greatly reduce radio congestion on the clearance delivery frequency as well as issue clearances with greater efficiency and accuracy. Not to mention add a new level of realism to your simulation.

Enjoy!