Digital data messaging between pilots and air traffic controllers is scheduled to begin replacing voice-based communications in U.S. airspace in the next three years.

The FAA plans to deploy data communications in domestic airspace for ATC towers by 2015 for revised pre-departure clearances and routine communications, and for air route traffic control centers (ARTCCs) by 2018 for en route messaging. The provision of data communications in domestic airspace will feather into a requirement for datalink capability in North Atlantic oceanic airspace slated to begin in 2013.

The data communications–or DataComm–effort is considered one of six “transformational” programs leading to the Next Generation Air Transportation System (NextGen). Data messaging for air traffic services is expected to improve controller productivity and reduce workload by automating delivery of routine clearances, freeing controllers to handle increased traffic. Safety will be enhanced by reducing misunderstandings and radio congestion arising from voice communications. Data communications are integral to the networked, data-centric vision of NextGen.

Success is not assured. “Developing and implementing DataComm will be a complex, high-risk effort, and industry officials have expressed skepticism about the FAA’s ability to deliver the program,” Calvin Scovel III, Department of Transportation inspector general, stated in testimony to the U.S. House in October.

Eventual Fans Replacement

The FAA is currently evaluating industry proposals for its data communications integrated services (DCIS) acquisition, which were due to the agency in early October. Citing “source selection sensitivity,” the agency declined to identify vendors that responded or to provide the number of proposals received in response to the DCIS request for offers. AIN has verified proposals by at least two companies–Harris and ITT Exelis. Harris is prime contractor of the FAA telecommunications infrastructure, the network supporting voice, data and video communications at FAA and Department of Defense facilities. ITT Exelis is building the ground infrastructure for automatic dependent surveillance-broadcast (ADS-B), a nationwide network of radio stations.

The FAA also declined comment on the expected DCIS contract value, but said the program is on track for a contract award next year. According to the DOT IG, the FAA has estimated total acquisition costs could be as much as $3 billion.

The chosen contractor will provide ground-to-ground and air-to-ground segments of a data network between FAA air traffic service points and data comm-equipped aircraft. In the DCIS solicitation, the FAA said it expects the contractor to use one or both of the current commercial providers of air/ground communications–a reference to Arinc and SITA–to provide a VHF Digital Link Mode 2 (VDL-2) datalink for air traffic services that also accommodates aircraft communications addressing and reporting system (Acars) messages. Acars is used mainly for data communications between an airliner and its operations center.

In addition to the network service, the DCIS contractor will be required to administer a “Data Communications Avionics Equipage Initiative,” with $80 million in funding to supply early adopters with the necessary Future Air Navigation System (Fans) 1/A+ avionics package, building on an equipment set already used for oceanic datalink communications. The solicitation states that no more than 10 percent of the funding may be used to equip Part 135 commuter and on-demand aircraft, with the balance used for carriers operating under Part 121. The overall plan for data communications is to migrate from the Fans standard to the global Aeronautical Telecommunications Network (ATN) protocol for oceanic and domestic operations.

The capability for data communications is focused on Part 121 carriers and high-end GA aircraft. What will be industry’s cost to equip? The NextGen Advisory Committee (NAC) advising the FAA on deploying NextGen estimates 64 percent of the Part 121 fleet forecast in 2020 could be equipped for Fans 1/A+ over VDL-2 for $1.3 billion. The remaining 36 percent of the expected 2020 fleet, primarily regional jets and single-aisle airliners, have no upgrade path identified for Fans 1/A+. A partial survey of high-end GA aircraft indicates 7 percent of the forecasted 2020 fleet of 10,932 aircraft could have Fans capability over VDL-2 at a cost of $118 million. The remainder of the surveyed fleet has no Fans upgrade path identified.

The FAA has said it is considering implementing an incremental standard between Fans and ATN, designated ATN Baseline 1 (ATN B1), that would align sooner with Europe’s 2015 data communications retrofit mandate under the Link 2000+ program. In a joint letter to the NAC, Airbus and Boeing say they oppose ATN B1 because it is not an “integrated” standard, or one allowing for the exchange of digital messages between ground automation systems and aircraft flight management systems (FMS). It is also not necessary to comply with Europe’s requirement, they argue, because aircraft equipped with Fans 1/A systems are exempt from the mandate. The NAC has noted, however, that requiring FMS autoload capability for domestic ATC datalink “will preclude many regional aircraft from participating and will incur opportunity costs for operators who could cost-effectively implement ATN B1.”

The data communications network on the ground will interface with ATC automation platforms–the Tower Data Link Services system for airport towers and the En Route Automation Modernization (Eram) system being installed at 20 Artccs. In response to an AIN query regarding the Data Comm program, the FAA said, “Significant work is being done to provide the necessary software enhancements to domain automation software, but that design and development work is being executed through existing [contract] vehicles already active in the FAA Terminal and En Route offices.” The Eram contract with Lockheed Martin is being used to provide a national logon capability and a protocol gateway, required for both tower and en route services.

The FAA’s DataComm program office plans to conduct trials at designated towers in 2013, and to launch formal integration testing in October that year. To support the testing, the DCIS contractor will be required to provide a test tower service at the FAA’s William J. Hughes Technical Center in Atlantic City, N.J. Formal operational test and evaluation (OT&E) of the system is linked to Eram, a program that is running four years late and is slated for completion in 2014. After successful completion of OT&E, the DataComm program will begin deploying services to 73 towers in 2015. The initial set of DataComm services includes revised departure clearances, weather reroutes, tailored arrival flight paths, direct-to-fix and crossing restrictions, according to the FAA.