Controller-pilot data link communications (CPDLC) Build 1 value-added services

The Federal Aviation Administration's (FAAs) controller-pilot data link communications (CPDLC) Build 1 system began initial daily use (IDU) at Miami Air Route Traffic Control Center (ARTCC) on October 7, 2002. CPDLC utilizes the aeronautical telecommunications network (ATN) and very high frequency digital link (VDL) mode 2 to transmit digital messages between air traffic controllers and pilots in specially equipped aircraft. In addition to the FAA and the Miami ARTCC, stakeholders include ARINC, American Airlines, Continental Airlines, Delta Airlines, Atlantic Southeast Airlines (ASA), the United States Air Force, Rockwell Collins, and Teledyne. CPDLC Build 1 consists of four basic services: transfer of communications (TOC) for directing a pilot to change the assigned voice frequency; initial contact (IC) for verification of the pilot's assigned altitude; altimeter setting (AS) for uplinking barometric pressure data, and menu text (MT) for uplinking a predefined set of text messages. These services are invoked through five message types: contact; monitor, usually combined with confirm assigned level (CAL); "independent" CAL; altimeter setting; and menu text. CPDLC Build 1 was to have been the first step in an evolution of data link capabilities that would eventually provide data link services to all centers through a series of builds intended to keep pace with similar developments in Europe. It was planned to be a limited duration, single site implementation to prove the viability of CPDLC procedures and capabilities, to be followed by the national deployment of CPDLC Build 1A. However, in April 2003, the FAA's Joint Resources Council (JRC) decided to defer CPDLC Build 1A, but directed the CPDLC team to prepare a sustainment plan for continued Build 1 operations in Miami. The sustainment plan (2003) was prepared in July 2003 and included plans for the resolution of existing operational issues and implementation of program refinements. Key among the latter included expanding existing capabilities at little or no cost through value-added services. This paper summarizes CPDLC Build 1 operations since IDU and describes some innovative approaches for expanding its limited capabilities with minimal impact on existing systems (e.g., procedural) and cost to the program office.