PDCs let controllers issue IFR clearances via private message during high-traffic periods — keeping frequency congestion down and getting pilots on their way faster.
Pre-Departure Clearances are issued when the Winnipeg FIR is handling high volumes of traffic — most commonly during cross-the-pond or other major VATSIM events. Controllers may also choose to use PDC at any time at their discretion if required.
Winnipeg's PDC system uses the private message (PM) protocol supported by all VATSIM-approved pilot clients.
Pilots can request a PDC from ATC by voice or text before departure. The controller will respond with a private message containing your full IFR clearance — active runway, assigned SID, squawk code, and more.
Read the PDC carefully — it is your IFR clearance and should be treated as such. If your flight plan is invalid or requires amendment, the PDC will include AMENDED ROUTE; check the routing before accepting.
Once you have your PDC and understand, note the ATIS letter, and call ATC when ready for push and start — quoting your PDC identifier.