A 2015 mandate for controller-pilot data link communications (CPDLC) in European airspace above 28,500 ft.—Flight Level 285—will represent the most lucrative opportunity in the airline retrofit market in 2013 for avionics makers.

Called Link 2000+, the rule calls for the installation of airborne data link systems that can process nearly 100 uplink and downlink messages, most of which are pre-defined text messages for “non-critical” communications. Over a VHF voice link, those non-critical contacts can occupy 50% of a controller's time, impacting capacity. Having “canned” text messages will also help to reduce miscommunications and stuck-microphone issues.

Typical CPDLC uplink commands include “climb to,” “descend to” and “fly heading” requests, which pilots respond to by clicking “wilco,” “unable” or “stand-by” buttons. Canned requests for pilots to send to controllers include climbs or descents and weather deviations. Both pilots and controllers can also send free text messages for events not covered by pre-defined messages. If a microphone is stuck in the “transmit” mode, blocking voice communications, controllers can send pilots a text message to investigate the situation.

According to Honeywell Aerospace, the controller workload reduction will result in an upper airspace capacity increase of 11% when 75% of the participating aircraft are equipped. “The second benefit, on the pilot's side, is that there is reduced workload and fatigue from radio telephony,” says Aileen McDowall, director of air transport and regional technology sales at Honeywell. “Currently, pilots have to listen to each radio message and only one in 20 messages is applicable to their aircraft.”

While new aircraft were required to have the required equipment installed from the factory as of Jan. 1, 2011, the existing fleet was given until Feb. 5, 2015, to equip. Air navigation service providers in the region are required to have the ground infrastructure in place by early 2013 or 2015, depending on their location (see map, page 130), though there are some indications that the February 2013 date is overly optimistic.

For many airlines, 2013 is a “do-or-die” year for scheduling fleet upgrades for the 2015 mandate, in order to overlap the Link 2000+ maintenance work with regularly scheduled C and D heavy maintenance checks rather than to risk taking aircraft out of service unnecessarily.

In the cockpit, the Link 2000+ retrofit generally requires changes or additions in four areas. The aircraft must have a third radio that is VHF Digital Link Mode 2 (VDLM2)-capable; it must have a multi-function display that can show the text messages and allow for pilot responses; it must have an aural or visual alert that lets the pilots know a message has arrived, and it has to have a communications management unit (CMU) that acts as the CPDLC router and application. McDowall notes that the CMU “is the brains” of the operation.

The relatively high-rate (31.5 kbps) VDLM2-addressable messages are passed between air and ground using upgraded Arinc or SITA ground stations that typically carry Aircraft Communications Addressing and Reporting System (Acars) messages.

“For most airlines, it's a fairly significant upgrade for hardware and software for more than one [of the three] pieces of equipment,” says McDowall, noting that under a best-case scenario it will cost roughly $10,000 to meet the mandate. “Worst case is that there is not [a] third radio or CMU. Then it gets toward a significant cost.”

European airlines had the opportunity for help with those costs as part of a Eurocontrol subsidy program during the early “pioneer” phase of the Link 2000 program, which started in 2003. “Some did,” says McDowall of the aid. “The vast majority did not.”

The pioneer phase involved airlines and controllers using CPDLC in the Maastricht upper airspace sector, a practice that will continue in trial mode for equipped aircraft until more European air navigation service providers (ANSPs) phase in the new service.

A similar rollout in the U.S. will take a much more measured approach. As part of the Data Communications Integrated Services (DCIS) program, which the FAA awarded to Harris Corp. in September, CPDLC will be used by airlines to get updates to pre-departure clearances at five trial airports in 2015, followed by a broader implementation thereafter.

The contract includes $80 million to help airlines equip for CPDLC, which will initially work only with the aircraft using the Future Air Navigation System (FANS) 1/A architecture. This includes a different message set from the Aeronautical Telecommunications Network (ATN) protocol that Eurocontrol is implementing. FANS 1/A is typically used for air traffic services and Acars capability for oceanic routes. The contract calls for Harris to roll out the operational infrastructure for CPDLC in the airport environment by 2018 and in the en-route phase by 2023. While factory-built aircraft can already be equipped for the FANS 1/A CPDLC, retrofits for the U.S. operations could cost anywhere from $30,000 to $500,000 per aircraft for the legacy fleet, experts say.

A key difference between U.S. CPDLC and Link 2000+ is that the FAA is requiring that operators capture data link messages on the aircraft's cockpit voice recorder, while no such requirement exists in Europe. “Europe is looking to implement that, but there's nothing hard and fast on the recording,” says McDowall. “Some in Europe are upgrading recorders in advance but it depends on their ties to U.S. airlines. For the most part they're sitting tight. There are a lot of questions and a lot of uncertainty.”

The cost of the avionics upgrade could be highly dependent on whether the operator uses the original equipment manufacturer (OEM) or third-party provider.

“We're confident the only other solution out there will be a very expensive one—the OEM,” says Scott Campbell, director of airline and military sales for Universal Avionics, a provider of CMUs and flight management systems (FMS) and other avionics. “We will be able to come in for a fraction of the cost.” The OEMs in this case are typically Honeywell, Rockwell Collins and Thales.

Campbell says the “low-hanging fruit” for Universal is the regional and corporate jet market, but that its equipment will “most certainly” work for heavier aircraft as well. He says the market size is “in the thousands.”

Though the Link 2000+ mandate applies to altitudes above where regional jets typically fly, operators may decide to equip regardless. “There is a line of thinking that these operators will want [to equip] because they don't want to be stuck in the penalty box somewhere,” says Campbell, alluding to the much touted “best-equipped, best-served” priorities for next-generation air transportation systems.

Universal already sells a FANS 1/A-compliant “Unilink” CMU for Acars uses, and is developing a Link 2000+ software update to handle CPDLC messaging. The CMU includes a VDLM2 radio, says Campbell. He says that while customers with the Universal CMU tend to have a Universal FMS, the software upgrade will make the CMU compatible with third-party FMS, increasing the potential for retrofit work, which he predicts will cost about $100,000 per aircraft, not including labor.

“Some of the operators we're talking to are looking at provisioning the aircraft, installing the rack and the wiring and putting the box in later,” he says, adding that Universal is planning to roll out Link 2000+ training software in 2013.

Honeywell doesn't appear to be worried about the competition from third-party avionics providers. “Most airlines will have to work with Honeywell to meet this mandate,” says McDowall. She says a third-party solution may make financial sense for “some operators who had very minimal equipage,”but she says for the “vast majority” it makes more sense to go through the OEM. “If they go non-OEM for current mandate, what does it do for the future?” asks McDowall.

Craig Peterson, director of marketing for avionics and flight controls for Rockwell Collins, says that Boeing and Airbus and other airframers who have already had to deal with the “first wave” of Link 2000+ equipage due to the 2011 forward-fit mandate will help OEMs retain the retrofit business. “Since [airframers] made sure production lines were compliant, then ultimately they're incentivized to promote that [avionics kit] as a continuity solution,” says Peterson. “They typically promote that production base to the installed-base community.”

McDowall says there has also been “some concern” about approved third-party equipment in terms of human factors. “One maker is very adamant about the visual signals [of an incoming CPDLC message] in the pilot's forward field of view. It has received supplemental type certificate, but it may not be optimal.”

So when will airlines decide to equip?

“Most operators are waiting,” says Universal's Campbell. “I think [this] year they'll be starting to ramp up a little bit, but airlines tend to do things at the last minute. As we get closer, things will continue to ramp up.”

McDowall is beginning to see momentum building as well. “There has been a slow start. But I'm starting to see in the last few weeks, starting to get a little faster in the takeoff,” she says. “Customers are signing up for upgrades in their fleet; the bigger ones for sure.”

She says the tempo needed to meet the mandate is a concern for Honeywell. “A lot of equipment has to get software upgrades, but in most cases it has to come through a shop to get hardware upgrades,” she says. “We're working with larger airlines to schedule the shop visits.”