AIM ¶ 5-2-2 — Pre-Departure Clearance Procedures
AIM 5-2-2 explains PDC and CPDLC-DCL automated pre-departure clearance procedures, limitations, and differences for IFR pilots preparing for checkrides.
In Plain English
Many towered airports use the Terminal Data Link System (TDLS) to deliver IFR clearances electronically instead of by voice. There are two flavors:
- PDC (Pre-Departure Clearance): The clearance is sent from the ARTCC to the tower, the controller adds local departure info, then it's pushed via the airline/service provider through ACARS (or printed at the gate). No pilot acknowledgment or read-back is required.
- CPDLC-DCL (Controller Pilot Data Link Communication–Departure Clearance): The clearance is uplinked from the tower directly to the aircraft avionics via FANS, and the flight crew must respond.
Both services reduce frequency congestion, controller workload, and read-back errors, but are only available to subscribed participants.
Key limitations:
- PDC: One clearance per departure airport per 18 hours; revised clearances kick out to voice delivery.
- CPDLC-DCL: Unlimited clearances, supports revisions, requires logon to KUSA (FAA National Single Data Authority) and proper ICAO flight plan equipment coding.
If anything looks off, call Clearance Delivery to verify.
AIM Source Text
FAA AIM ¶ 5-2-25-2-2. 5-2-2. Automated Pre-Departure Clearance Procedures
Many airports in the National Airspace System are equipped with the Terminal Data Link System (TDLS) that includes the Pre-Departure Clearance (PDC) and Controller Pilot Data Link Communication–Departure Clearance (CPDLC-DCL) functions. Both the PDC and CPDLC-DCL functions automate the Clearance Delivery operations in the ATCT for participating users. Both functions display IFR clearances from the ARTCC to the ATCT. The Clearance Delivery controller in the ATCT can append local departure information and transmit the clearance via data link to participating airline/service provider computers for PDC. The airline/service provider will then deliver the clearance via the Aircraft Communications Addressing and Reporting System (ACARS) or a similar data link system, or for non-data link equipped aircraft, via a printer located at the departure gate. For CPDLC-DCL, the departure clearance is uplinked from the ATCT via the Future Air Navigation System (FANS) to the aircraft avionics and requires a response from the flight crew. Both PDC and CPDLC-DCL reduce frequency congestion, controller workload, and are intended to mitigate delivery/read back errors. Both services are available only to participating aircraft that have subscribed to the service through an approved service provider. In all situations, the pilot is encouraged to contact clearance delivery if a question or concern exists regarding an automated clearance. Due to technical reasons, the following limitations/differences exist between the two services: PDC Aircraft filing multiple flight plans are limited to one PDC clearance per departure airport within an 18-hour period. Additional clearances will be delivered verbally. If the clearance is revised or modified prior to delivery, it will be rejected from PDC and the clearance will need to be delivered verbally. No acknowledgment of receipt or read back is required for a PDC. CPDLC-DCL No limitation to the number of clearances received. Allows delivery of revised flight data, including revised departure clearances. A response from the flight crew is required. Requires a logon to the FAA National Single Data Authority - KUSA - utilizing the ATC FANS application. To be eligible, operators must have received CPDLC/FANS authorization from the responsible civil aviation authority, and file appropriate equipment information in ICAO field 10a and in the ICAO field 18 DAT (Other Data Applications) of the flight plan.
Oral Exam Questions a DPE Might Ask
Q1What is the difference between PDC and CPDLC-DCL?
Per AIM 5-2-2, PDC delivers the clearance via the airline/service provider through ACARS or a gate printer with no pilot acknowledgment required, while CPDLC-DCL uplinks the clearance directly to the aircraft avionics via FANS and requires a response from the flight crew. CPDLC-DCL also supports revised clearances and has no limit on the number of clearances delivered.
Q2What are the limitations of a PDC clearance?
Per AIM 5-2-2, aircraft filing multiple flight plans are limited to one PDC clearance per departure airport within an 18-hour period — additional clearances must be delivered verbally. If a clearance is revised or modified before delivery, PDC will reject it and it will be issued verbally. No read-back is required for a PDC.
Q3If you have a question about an automated clearance you received, what should you do?
Per AIM 5-2-2, the pilot is encouraged to contact Clearance Delivery any time a question or concern exists regarding an automated clearance, regardless of whether it was delivered via PDC or CPDLC-DCL.
Related Paragraphs in AIM Chapter 5