Notes regarding the operational use of PDC in the US:
- A PDC does not have an option for crew acknowledgment and the FAA does not expect a response.
- A PDC will fail (not generate) as soon as there is a change to the time or route of the filed flight plan. The change could be prompted by either crew or ATC. In other words, a PDC will only be available under ideal circumstances.
- Operators capable of the FANS DCL clearance option can only receive the FANS DCL or the PDC - never both. In some cases, an operator may fail to remember that the departure is from one of the 62 FANS DCL-enabled airports in the US and may have filed the departure clearance preference in Field 18 as "DAT/1FANS2PDC". The operator may expect a PDC, which never generates because ATC has a FANS DCL clearance ready to distribute and is only waiting for the operator to perform a FANS logon to "KUSA".
FANS DCL in the US:
At present, only the US delivers Data Link Departure Clearances using the FANS protocol. FANS CPDLC equipped aircraft may utilize VHF Data Link to perform a FANS logon to "KUSA" at the 62 eligible airports across the US. The logon is accepted up to 90 minutes prior to the filed departure time. Flight plans will need to show the form of VHF Data Link in use in Field 10a ("J3" for VDL Mode 0/A and/or "J4" for VDL Mode 2) and the operator's departure clearance preferences in Field 18 DAT/ ("1FANS2PDC" describing the first preference as FANS DCL if available, otherwise PDC). Alternatively, the departure clearance preferences can be managed in the FAA's SDB by ARINCDirect.
Data Link Departure Clearances Globally:
Outside of the US, a selection of airports support DCL via the ARINC623 protocol on the ACARS network. Operators state their DCL capability by means of filing a flight plan indicating the equipment suffix "E3" in Field 10a. The Departure Clearance Request is generated by means of completing a request form in the ATC menu of the avionics, often located in the vicinity of the Oceanic Clearance Request. If unsure of the submenu, please check with your OEM. Upon receipt, ATC will respond by means of an ACARS uplink to the aircraft.