AIM 8/15/19  Section 2. Departure Procedures 5 − 2 − 1. Pre-taxi Clearance Procedures 1. PDC 2. CPDLC − DCL 5 − 2 − 2. Automated Pre − Departure Clearance Procedures 5 − 2 − 1 Departure Procedures a. Certain airports have established pre-taxi clearance programs whereby pilots of departing instrument flight rules (IFR) aircraft may elect to receive their IFR clearances before they start taxiing for takeoff. The following provisions are included in such procedures: 1. Pilot participation is not mandatory. 2. Participating pilots call clearance delivery or ground control not more than 10 minutes before proposed taxi time. 3. IFR clearance (or delay information, if clearance cannot be obtained) is issued at the time of this initial call-up. 4. When the IFR clearance is received on clearance delivery frequency, pilots call ground control when ready to taxi. 5. Normally, pilots need not inform ground control that they have received IFR clearance on clearance delivery frequency. Certain locations may, however, require that the pilot inform ground control of a portion of the routing or that the IFR clearance has been received. 6. If a pilot cannot establish contact on clearance delivery frequency or has not received an IFR clearance before ready to taxi, the pilot should contact ground control and inform the controller accordingly. b. Locations where these procedures are in effect are indicated in the Chart Supplement U.S. a. 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 Communica- tion–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. b. Both services are available only to participating aircraft that have subscribed to the service through an approved service provider. c. 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/differ- ences exist between the two services: (a) 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. (b) 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. (c) No acknowledgment of receipt or read back is required for a PDC. (a) No limitation to the number of clearances received. (b) Allows delivery of revised flight data, including revised departure clearances. (c) A response from the flight crew is required. (d) Requires a logon to the FAA National Single Data Authority  −  KUSA  −  utilizing the ATC FANS application. (e) To be eligible, operators must have received CPDLC/FANS authorization from the