Future Air Navigation System (FANS) technology is a form of Controller to Pilot Data Link Communications (CPDLC) that uses the Aircraft Communications Addressing and Reporting System (ACARS) network for air traffic controller to pilot text messaging. Primarily, it has been designated for use over the North Atlantic Tracks (NAT) oceanic airspace. However, some of the functionality is currently being pushed into the domestic United States as part of the Data Comm initiative for the FAA’s NextGen program. This year, the FAA deployed the initial phase of Data Comm using FANS 1/A+ to facilitate automated Departure Clearance (DCL) between aircraft and air traffic controllers at Newark Liberty International Airport, Memphis Airport, George Bush International Airport, Houston William P. Hobby Airport and Salt Lake City.
Europe is using Protected Mode CPDLC (PM CPDLC) or Link 2000+, which is similar to FANS. Link 2000+ is a form of pilot to controller data link communications that uses the Aeronautical Telecommunication Network (ATN), leveraging some VHF data capabilities to provide improved data integrity. After originally mandating PM CPDLC equipage for aircraft flying above 28,000 feet by Feb. 5, 2015, the European Commission delayed that mandate until 2020.
International Civil Aviation Organization’s (ICAO) Global Operational Data Link Document (GOLD) provides the industry’s best guide to the hardware required to perform FANS operations, and comply with the NAT DLM as well as Europe’s Link 2000+ PM CPDLC mandate. Generally, both business jets and commercial airliners require the following equipment to be compliant with FANS mandates:
1. A Flight Management System (FMS) and a Multi-purpose Control Display Unit (MCDU) that is capable of being your interface for your CPDLC text messages;
2. ARINC 741 Level D compliant satellite communications system. Operators using Inmarsat service need the satcom system to meet Technical Standard Order (TSO) C-132. The use of Iridium requires TSO C-159A;
3. Cockpit Voice Recorder (CVR) capable of recording data link communications;
4. Communications Management Unit (CMU); and
5. Very High Frequency (VHF) transceiver that features VDL Mode 2 capability.
Based upon the aircraft’s original equipage and the service bulletins that have been adopted by the operator, an aircraft could require an upgraded FMS or CVR to record the data link messages. The best decision operators of business and commercial-class aircraft can make is to consult with their installation facility or the Original Equipment Manufacturer (OEM) to find out what equipment upgrades they may need.
“Anything that has to do with air traffic data communications to the ground, whether that’s a FANS activation in the United States or over oceanic or CPDLC over the ATN network in Europe, we are seeing a lot of that demand for avionics modifications to enable that right now,” says Bob Dankers, director of avionics modifications at Boeing.
“You have FANS for the oceanic and the United States and you have CPDLC using the ATN network and typically those are an either or type of installation depending on where you are going to operate,” he adds, noting that in-production 777s, 747-8s and 787s are FANS compliant coming out of the factory. Boeing also has upgrade paths available for legacy 737 airframes.
Legacy long-range business jets capable of flying within the NAT and the United States and Europe are also eligible for FANS 1/A+ upgrade paths. According to Jeff Gayon, director of product support technical sales and development for Gulfstream, the Savannah, Ga.-based airframe manufacturer has developed a standard FANS 1/A+ package for in production G280 aircraft and is currently evaluating FANS 1/A+ upgrade packages for legacy G100s, G150s and G200s. Additionally, FANS 1/A comes standard on the G650, and there are also standard “mandates packages” available for the G450 and G550, he says. Gulfstream is also targeting fourth quarter standard retrofit options on the GIV and GV. “The FANS requirements for the GIV and GV, the GV will be certified prior to NBAA, the GIV SP will be certified by the end of 2015 and the straight GIV will be certified in Q1 2016. We have a complete suite for the GIVs and GVs that we can use to update the new technologies into the airplane and advanced features in the display system,” says Gayon.
Operators also have the option of getting FANS compliant through installations performed at a third party Maintenance, Repair and Overhaul (MRO) facility. Mark Francetic, regional avionics manager at Duncan Aviation, the second largest MRO organization in the United States, says the company is seeing demand increase on older Bombardier, Dassault Falcon and Bombardier Challenger business jets. “Challenger 601s, Challenger 604s, Falcon 50s, are all airplanes that go over the water that will need FANS or if they will be operating over in Europe, it needs FANS,” says Francetic. He estimates the average cost of a FANS upgrade for a legacy business jet to start at $300,000. “There are certain European mandates, FANS being one, that mandates flying over the Atlantic. That one was a big one. So, for example, we wouldn’t put FANS on a Phenom but we definitely did on the Challengers and above that are flying across the Atlantic,” says Kyle Gill, director of cockpit configuration at NetJets. Gill notes that the increasing use of data link technology to communicate with air traffic controllers is a big advantage for NetJets pilots.
The majority of airliner aircraft based in Europe are equipped with FANS equivalent avionics for PM-CPDLC, as the European Link 2000+ program had previously mandated data link equipage for February 2015. That mandate has been delayed until February 2020 after flight testing showed that ground automation systems were incapable of handling CPDLC messages from Europe’s daily flight volume, which can reach up to 30,000 on the busiest days, NATS UK estimates. Some airlines, such as Scandinavian Airlines (SAS), are disappointed by the inability of the ground automation systems to support CPDLC at this time.
|Aircraft data link communications concept of operations.
Photo courtesy of Duncan Aviation
Nowhere is FANS more applicable today as an airspace mandate though than the NAT. There are now an estimated 420,000 aircraft flying the North Atlantic System every year, it is currently the world’s busiest airspace with commercial, military and business jets flying Reduced Vertical Separation Minimum (RVSM) procedures everyday.
Last year there were a total of 420,000 flight operations in the North Atlantic Track System, and air traffic volume within the airspace has grown nearly 5 percent per year over the last 15 years. During this time, NATS UK, the United Kingdom’s Air Navigation Service Provider (ANSP) has experienced a significant rise in FANS equipped aircraft, driven by a number of factors. The most relevant of these have been the introduction into service of new aircraft types such as the B787 and A380, plus the decision by the ICAO North Atlantic Systems Planning Group (NATSPG), the state level governance body responsible for the safety, performance and development of this airspace, who mandated the use of FANS to improve safety within the airspace. Today, more than 80 percent of the NAT fleet is FANS-equipped, a number that is rising steadily, according to Andy Smith, manager of ATC Development for NATS UK. Within the most densely populated parts of NAT airspace, the NAT Organized Track System (OTS), the proportion of FANS equipped aircraft is higher, reflecting high levels of airline investment in these systems.
Phase 2 of the North Atlantic Data Link Mandate has just come into effect this year as well to further enhance safety and reduce collision risk within the NAT. As of February 5, 2015, all aircraft operating in the NAT OTS between 35,000 and 39,000 feet are required to be equipped with FANS 1/A CPDLC and ADS-C avionics. Since this is within the oceanic environment, the aircraft also needs a satellite communications unit to satisfy this requirement. Phase 2B of the NAT DLM will expand to the entire ICAO NAT region. Finally, in January 2020, the mandate will be expanded to all altitudes above 29,000 feet.
“With FANS and CPDLC, the ground ATM system and aircraft avionics have been developed to work with each other to routinely exchange basic flight data, quickly and reliably. Moreover, the use of ‘contracts’ between both systems, enables certainty around key flight data. The contract will agree how often routine position reports are received, plus they will provide timely and automated alerts when the flight profile deviates from the clearance the controller has assigned. This contract is supplemented with the use of data link, to communicate quickly between controller and pilot and intervene to apply new control measures and/or correct non-conformances. FANS provides the opportunity to track the aircraft routinely at intervals of 14 minutes and also, in emergency or to interrogate non-conformances, at reduced intervals of around a minute, or whenever the controller wants to assure themselves of the aircraft status,” says Smith.
ICAO Air Navigation Bureau Director Stephen Creamer says the use of FANS within the NAT system is an essentially element of the global agency’s Aviation System Block Upgrades (ASBUs) program for Block 0 and transitioning into Block 1 over the next three years. “The technologies and the procedures that are being utilized in the North Atlantic are technologies that are available out of the ASBUs and block 0. So you can look at the technology inventory there and you can see them being employed to create the reductions in lateral and longitudinal separation. A key element of that is the states involved in that region are working together really closely on that oversight component. They are evaluating the risk and they are doing the safety risk management documentation so that they are assured that they are maintaining a high level of safety,” he says.
In the United States, the FAA has deployed data communications infrastructure that uses available FANS 1/A and VDL mode 2 avionics. In August, the agency published Advisory Circular 120-70C (AC 120-70C) to include domestic data communications ground services and the European ATN Link 2000+. To support more advanced data communications services, the FAA will support the use of ATN avionics in the future. ICAO developed the ATN to provide a more globally interoperable data communications system, and Europe’s current February 2020 PM CPDLC based on the early version of this, ATN Baseline 1.
Going forward, the plan is for the United States and Europe to domestically support ATN Baseline 2 (ATN B-2), which fuses the oceanic FANS 1/A+ and land-based ATN B-1. In December, RTCA Special Committee 214 and Eurocae’s WG78 held a meeting to discuss the finalized revisions for the standards for all ATN B-2 documents, including DO-350, DO-351, DO-352 and DO-353. SC-214 expects to publish the first revision for Baseline 2 documents in March 2016. ATN B-2 standards support advanced capabilities such as 4D Trajectories, Dynamic RNP and Advanced Flight Interval Management with ATC winds. This is the protocol, ATN B-2, that the two leading standards committees in the United States and Europe expect to be embraced globally as the evolution of FANS 1/A+ data communications.
NATS UK’s Smith believes the future of FANS, at least in the North Atlantic region, begins in 2018. “The future of FANS, alongside the evolution of satellite based ADS-B surveillance, is an exciting prospect that promises numerous benefits. These include furthering a reduction in separations, creating more space for aircraft to operate even more efficiently thus reducing fuel use and GHG emissions, and bringing further improvements to airline efficiency. This future isn’t far away with NATS, and it’s collaborative partners NAV CANADA, at the forefront of deploying these new technologies side by side with each other. This change will be transformational, and by 2018 we’ll begin to see the future of air traffic management deployed across the North Atlantic,” says Black.
Woodrow Bellamy III is the associate editor for Avionics Magazine.