The USA is revolutionising its air traffic management system to make it more efficient, safer and greener. The plan for NextGen is under way and the FAA is targeting 2018 as the date when operators will begin to reap its benefits. Our special report looks at the technology behind the ambitious programme and the steps needed to bring it to fruition



The US Federal Aviation Administration has adopted a pragmatic approach to the future of its national airspace system, based on a desired mid-term outcome that makes the best of technologies already available and gives industry a leading role in showing the way forward, largely through a wide array of demonstration programmes.

 © Rex Features
Self-separation and real-time in-cockpit incursion alerts are NextGen technologies the FAA is hoping to make "NowGen"

"We realised a couple of years into the Joint Planning and Development Office's visionary work that we needed an FAA plan to implement NextGen," says Vicki Cox, a senior FAA vice-president of NextGen and operations planning. "To get there we have to take baby steps. They're not nearly as exciting [as the long-term vision], but they are necessary." The Joint Planning and Development Office is a mix of transport-related government agencies charged by the US Congress in 2003 with bringing NextGen to fruition by 2025.

What that has meant for the FAA is leaving much of the long-term planning to the office, while getting to work on activities in the short to mid-term that would both further the long-term agenda and begin "selling" the idea to stakeholders, who would ultimately be asked to pay for the upgrades that NextGen would require. In January, the FAA laid out its first concrete plans for how to "get there" in the form of 13 "roadmaps" for required infrastructure advances in areas such as aircraft, airspace procedures, automation, communication, surveillance and weather.

The infrastructure and associated "service" roadmaps target 2018 as the intermediate point where NextGen will become "NowGen" and where "operators will begin to reap the benefits of NextGen, including improved safety, increased operations and efficiency, and better environmental performance", says the FAA.


A key part of the roadmaps are in-service demonstrations, funded by the "enabling activities" portion of the FAA's burgeoning NextGen funding stream. Demonstration programmes include several co-operative ventures with Europe, including the Atlantic interoperability initiative to reduce emissions and a similar programme in the South Pacific, as well as programmes to reduce taxi times at congested airports such as New York Kennedy.

The other half of the NextGen budget, which topped about $700 million this year and is expected to rise to more than $800 million next year, is for "transformational" programmes.

Highest priority on the transformational list is the installation of the automatic dependent surveillance - broadcast network, the GPS-based "backbone of NextGen" that will replace the FAA's cadre secondary surveillance radars. The $1.8 billion project to set up the ground infrastructure, headed by prime contractor ITT, is on course to be complete in 2013.

ITT last year inaugurated the first en-route segment of the system, in southern Florida, and in autumn will begin operations at four so-called "critical" sites, including the Gulf of Mexico and Philadelphia International airport, where aircraft position data will be certificated as acceptable for use in air traffic control.

In the Gulf of Mexico, where radar services are not available, having ADS-B will boost efficiency and safety for gas and oil operators flying helicopters to platforms, but will also allow airlines to significantly reduce in-trail spacing while flying over the area.

Although the FAA plans to require operators to equip with ADS-B "out" (equipment that broadcasts a GPS-derived position and other data as a means for the FAA to monitor airspace) by 2020, operators will need to equip with ADS-B "in" to gain efficiencies in terms of advanced manoeuvres such as self-spacing, capabilities with which airlines including UPS have begun to experiment. ADS-B "in" brings traffic and aeronautical information into the aircraft, providing the means for self-separation and other capacity and safety-enhancing capabilities.


Teamed with avionics provider ACSS, UPS several years ago decided to equip its Boeing 757s and 767s with ADS-B software to allow its pilots to perform capacity-boosting merging and spacing operations when approaching UPS's Louisville, Kentucky hub, and for monitoring traffic movement on the airport surface.

Combined with continuous descent approaches, UPS is claiming fuel savings in the neighbourhood of 380 million litres (1 million USgal) a year with the technology.

Based on that success, the FAA is spending millions on similar ADS-B-related demonstration projects to allow passenger-carrying airlines to gain experience with ADS-B and evaluate the potential benefits. "We're going to look at what works," says Mike Romanowski, FAA's director of integration and implementation for NextGen. "This will lead to more realistic requirements and less risk. We'll drive the work to the point where we reduce the uncertainty in the approach."

Under a programme industry observers are calling Capstone 3 (named after the Capstone 1 and 2 programmes in Alaska, in which the FAA purchased ADS-B avionics for a select group of operators), US Airways is equipping 20 Airbus A330s with ACSS ADS-B software to test the technology in its operations at Philadelphia International airport. Romanowski says the US Airways project will be used to develop standards and define the air-to-air capabilities for merging and spacing. The carrier will also experiment with ADS-B as a means of performing flight-level changes during in-trail procedures on transatlantic flights.

In addition, US Airways will also test new runway safety methods made possible by using ADS-B "in" as a means to bring in to the cockpit traffic conflicts computed by airport-based ASDE-X, a system that today provides alerts only to controllers. The FAA also awarded a contract to Honeywell to investigate a similar incursion prevention programme using ADS-B and ASDE-X at Seattle Tacoma International airport and elsewhere using Alaska Airlines and JetBlue pilots.

But it is unclear if industry will "bite" based on what they see in Philadelphia, Louisville and Seattle. In a recent report by the US Government Accountability Office, officials said some operators considering early implementation had expressed concern that the "FAA may not follow through with the ground infrastructure, procedures, or separation standard reductions" needed to make ADS-B pay off.

The watchdog says the FAA could hedge its bet by not only developing those standards and infrastructure early, but also providing operational benefits to those who equip, a so-called "best-equipped, best-served" approach, which may also be accompanied by financial incentives such as sharing the cost of the equipment through subsidies or tax credits. A good example of "best-equipped, best-served" will be for NextGen data communications capabilities where messages are received and sent via datalink, a technology the FAA says will go live in the 2014 timeframe.

Now, when controllers are faced with unpredicted weather, "they effectively slow all aircraft down to give the controller time to devise reroutes and communicate new clearances by voice for each one", says the GAO. With data communications, however, a controller could uplink reroutes to all data communications-equipped aircraft without slowing them, then slow those aircraft that are not equipped, to provide each with clearances sequentially by voice.

Helping to better define what incentives may help sell NextGen is a new RTCA-sponsored group called the task force on NextGen mid-term implementation. The group's final recommendations on how best to make a business case for NextGen equipped are due in August, and will be "reflected in the budgetary process going forward", says Romanowski.

The strong recommendations come from a desire for operators to take advantage of the precision navigation capabilities already installed in most modern aircraft.

Examples abound for how area navigation and required navigation performance (RNP) are helping to save money and time. UPS reports saving between 113kg (250lb) and 210kg of fuel per approach with its RNP-based continuous descent approaches. Alaska Airlines has documented 5,300 flights since 2005 that avoided diversions using the navigation technology, saving it $8 million in 2008 alone.

Source: Flight International