Datalink departure clearance trials update

Voice communication is a pillar of air traffic management throughout all phases of flight - but nowhere is it as important as during surface operations. Finding space on the frequency to communicate can often times be challenge, especially when operations become irregular during weather events or peak push-times. Ground frequencies can become saturated with controllers providing taxi and clearance instructions to pilots and vehicles. To alleviate saturation, ANSPs have turned to more efficient ways to communicate route and clearance information to aircraft. Many airports around the world are using data link as a means to provide route and clearance instructions to the cockpit without using voice communications. The U.S. FAA's Tower Data Link System (TDLS) has been used for more than a decade to provide route clearance information to pilots via PreDeparture Clearance (PDC) messages. TDLS generates the PDC with data obtained from the HOST or ERAM flight data processor and sends it to a dispatcher working in the airline operations center for airlines using the PDC service. The dispatcher then forwards the PDC directly to the cockpit of equipped aircraft and the pilot via ACARS. PDCs are issued 20 to 30 minutes prior to departure and once issued, revisions cannot be generated. If a revision is necessary, the pilot and controller revert to voice communication to issue and accept the clearance instructions.