AIM Text
- 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.
- PDC
Source: FAA Aeronautical Information Manual · current edition · paragraph 5-2-2.
The short answer
This AIM section is FAA advisory guidance describing automated pre-departure clearance delivery via the Terminal Data Link System (TDLS), which includes PDC and CPDLC-DCL functions. Both data-link IFR clearances from the ATCT to participating, subscribed users to reduce frequency congestion, controller workload, and read-back errors. It supports IFR clearance delivery under 14 CFR 91.173.
Research Notes
Common Questions
What is the difference between PDC and CPDLC-DCL?
How many PDC clearances can I receive in a day if I filed multiple flight plans?
The AIM states aircraft filing multiple flight plans are limited to one PDC clearance per departure airport within an 18-hour period; additional clearances are delivered verbally. Revised or modified clearances are rejected from PDC and delivered verbally.
What is required to be eligible for CPDLC-DCL?
Per the AIM, operators must log on to the FAA National Single Data Authority (KUSA) using the ATC FANS application, hold CPDLC/FANS authorization from the responsible civil aviation authority, and file appropriate equipment information in ICAO field 10a and field 18 DAT.