For over 20 years the airlines have used data link to augment the voice communications for Airline Operational Communications (AOC) and Airline Passenger Correspondence (APC), that todays standard aircraft delivered for the factory includes an operational data link system. Due to the acceptance by the Airline Flight Crews and their daily use of the digital communications network, the Airlines requested that the FAA consider the data link network to provide Air Traffic Control informational messages.
In 1990, the FAA accepted this request which led to the development of the PreDeparture Clearance and Digital ATIS message projects. Both of these products are messages used by the Pilot for planning and guidance information.
The challenge now is to develop a International Standard data link network that can process Air Traffic System tactical and control messages to provide both the Airlines and the FAA's with operational benefits of “FREE” Airspace, which can only be achieved by augmenting the Voice message and command system with a combined voice/data message and command system, that will rely 90 percent on data link communications and 10 percent on voice communications.