Almost since the beginning of air traffic control in the U.S., the interaction between pilots and controllers has been based on talking via radio. But voice communication, like radar, is about to be overtaken by new technology.

The FAA aims to establish a data communications network to shift most controller-pilot messages—more than 1.2 million a day—to a digital text-based system. This will be one of the key enablers of the NextGen modernization effort, which requires aircraft to fly satellite-based procedures that are too complex for current ATC communications technology.

The agency's Data Communications (Data Comm) program will make it quicker for controllers to send and revise clearances, as well as reducing frequency congestion and allowing the transmission of complex flight profiles. Departure clearances and other instructions will be uploaded directly to an aircraft's flight management system (FMS), which will further streamline the process and cut error rates associated with manual entry.

Most of the major names in the aerospace industry are involved in bidding for the Data Communications Integrated Services (DCIS) contract, which will likely be one of the largest NextGen awards to date. The winning team will establish and operate the Data Comm network for up to 17 years, with the FAA paying a fee for the service. Contract award is expected in June.

Three teams have submitted bids to the agency for DCIS. The teams are led by Harris Corp., ITT Exelis and Lockheed Martin. None is revealing its bid amount yet.

Airlines have put their support behind the DCIS effort, says Ed Sayadian, vice president of air traffic management for ITT Exelis. “Nobody is arguing with the benefits this program will provide when fully deployed,” he says.

Peter Challan, vice president of government relations for Harris, says air carriers regard Data Comm as one of the NextGen initiatives that has the potential for significant user benefits, and it is backed by a strong business case. In addition, the FAA is including equipage funding in the contract to help deployment reach a “tipping point” in the airline fleet, he says.

Data Comm has been identified as one of the “foundational” NextGen programs, says Diane DeSua, Lockheed Martin's director of NextGen strategy. “This is the only way we can move to trajectory-based operations.” DeSua stresses that this will be one of the most complex programs the FAA has undertaken, with a network linking to a wide range of ATC platforms, as well as cockpit avionics. “It's a really large systems integration job,” she says.

The FAA, meanwhile, sees Data Comm as “necessary for the transition from a voice-based air traffic control communications system to data-centric NextGen, and [it will] serve as the primary enabler for many of the NextGen operational improvements,” says an FAA spokesman. The agency expects Data Comm will improve controller productivity and reduce workload by automating the delivery of routine clearances.

Data communication links for ATC are already used extensively on oceanic routes in the U.S. and elsewhere, and Eurocontrol uses them in the upper airspace it controls in Western Europe. The U.S. had an earlier program called Controller-Pilot Data Link Communications, but it was shelved in 2003.

The DCIS acquisition effort has been underway for more than two years, and the FAA “has spent a lot of time with the contractor community coming up with a viable, executable program,” says Challan.

The first stage of deployment, to be completed from 2015-18, will cover airport data communication services. This step will allow departure clearances to be streamlined. Five initial sites will be selected for testing, and the system will be deployed eventually to 73 airport towers.

Improving the departure clearance process will be one of the major benefits of the Data Comm program, says Sayadian. It will mean controllers can quickly revise multiple clearances to reroute aircraft during severe weather.

The Data Comm program will be expanded to en route centers from 2018-23, requiring a range of additional messages covering everything from altitude and route changes to tailored arrivals. Eventually the system will be used to send the complex information required for the four-dimensional trajectories that are a key NextGen element. A schedule for data communications to be applied in terminal airspace has yet to be determined.

The FAA has stipulated that DCIS will use the air-ground communication networks of Arinc and SITA, to take advantage of existing infrastructure. The winning bidder must strike a separate deal with one or both of these two companies, and will work with them to add to their networks where necessary. An advantage of this approach is that it avoids the need for separate aircraft equipage for Data Comm and existing applications used by airlines for sending digital messages to pilots.

A second component of the program covers airline equipage. The FAA has earmarked $80 million to be used to help carriers upgrade aircraft to use the service. The bidders must propose how that sum can provide incentives for at least 1,900 aircraft to be equipped for data communications.

While newer aircraft are capable of handling data communications, older fleets will need avionics upgrades. There will be no mandate for airlines to equip, although all are likely to participate, says DeSua.

The winning bidder will also have to supply integration and engineering support to the FAA as the system is rolled out. The agency will need to upgrade tower and en route ATC systems to align with Data Comm.

The service will initially use the Future Air Navigation System 1/A (FANS 1/A) standard via VHF Digital Link Mode 2, since FANS 1/A is already widely used for airline operations and for oceanic data communications. While FANS 1/A messages can be uploaded to the FMS, this standard cannot handle the more-complex messages needed for advanced procedures such as 4-D trajectories. A standard known as Aeronautical Telecommunication Network (ATN) Baseline 2 is being developed, and this will allow the more complex messages to be uploaded to the FMS.

One question that the FAA must still answer is whether Data Comm will support ATN Baseline 1 in addition to Baseline 2. Baseline 1 is regarded as an interim solution, and is the standard being used in the Link 2000+ data link program in Europe. Boeing and Airbus are among those recommending that the FAA does not include Baseline 1, as it would divert resources from the development of Baseline 2.

Because of the huge scope of DCIS, ITT has brought in expertise from all facets of the industry in its bid team, Sayadian says. ITT is the prime contractor for the FAA's Automatic Dependent Surveillance-Broadcast (ADS-B) program, which also involves the establishment of a nationwide network.

Included in the ITT team are air carriers United Airlines, JetBlue Airways and UPS, which have provided perspective on equipage and operations. Rockwell Collins contributes avionics expertise. Among the other team members are Airbus, Raytheon, General Dynamics, Aerospace Engineering, AT&T, Airtel, Northrop Grumman, CSC, Saab Sensis, Nav Canada and Nexa Capital Partners.

Harris Corp. has not yet released its full team list. However, the company says it includes Arinc, which is one of the prospective commercial network providers. Also in this team are GE Aviation, which will provide avionics expertise, and Thales. There is also a major airline partner, but Harris is not yet revealing which one.

The DCIS program “falls right in the wheelhouse” of Harris, says Challan. This is due to the FAA activities in which the company is already involved, particularly the FAA Telecommunications Infrastructure program.

The Lockheed Martin team includes Boeing, Level 3 and Telcordia. Lockheed is also not yet naming its major airline partners. DeSua notes that Lockheed was the prime contractor for the FAA's oceanic ATC system, which is the only system in the U.S. that currently uses controller-pilot data links. Boeing has already used data communications in various demonstration programs.