NextGen benefits are coming, slowly but surely

Aviation International News » July 2011
June 29, 2011, 6:20 AM

Despite all the fits and starts, NextGen in the U.S. will eventually affect business aircraft operators, although perhaps not on the schedule that the FAA currently espouses. It is not too soon to start considering the impact of NextGen on business aviation and how it will drive equipment requirements.

When the FAA air traffic control system was created, it had a simple mandate: keep aircraft apart. And that mandate stemmed from midairs that generated overwhelming public interest in crafting a way to keep aircraft from running into each other.

Fast forward a few years. Now we have the NextGen mandate, one that isn’t driven by accidents, which is a good thing because too many FAA regulations stem from tragedy. But because it isn’t driven by an overwhelming need to prevent immediate bloodshed, the Next Generation Air Transportation System is a kitchen sink of desirable features, an all-encompassing package of government and aircraft operator spending that promises to solve a lot of problems and that is going to cost a bunch of someones a lot of money.

Here is a seemingly innocuous statement from the latest version of the FAA’s NextGen Implementation Plan, recently updated in March: “The primary goals of NextGen are to enhance the safety and reliability of air transportation, to improve efficiency in the [National Airspace System] and to reduce aviation’s impact on our environment.”

Certainly these are well-intentioned goals, and they reflect the fact that the FAA’s mission has morphed into something more substantial than it was when the agency was founded in 1958. The NextGen plan is part of an effort to wrap ATC modernization into the FAA’s vision “to reach the next level of safety, efficiency environmental responsibility and global leadership.” When NextGen is fully implemented in U.S. airspace it will lead to great improvements in efficiency and consequent reductions in aviation-related emissions.

The global leadership part is debatable, because many air navigation service providers (ANSPs) around the world are in much more advanced stages of ATC modernization. In the U.S., NextGen funding remains hung up in FAA reauthorization legislation, which has been extended 19 times and remains bogged by legislators’ incessant penchant for adding burdensome special-interest riders onto the legislation. Many ANSPs in other regions are funded through user fees, which might explain why they are able to adopt new technology more quickly, but that’s an entirely different issue.

For operators, NextGen will affect three key areas: communications, navigation and surveillance, according to Andy McDowell, Jeppesen director of airspace and airports. “The goal of NextGen is higher capacity and efficiency within the system,” he explained. “The system consists of operations in airspace as well as on the ground. On surveillance, we’re looking at the transition to ADS-B. Communication is the move from voice-based to datalink. And navigation is the route structure based solely on RNAV and RNP. We’re going to have to have all three in place, the technology as well as the ATC operational plan that makes use of those technologies.” Surveillance is currently the sole FAA mandate, the Jan. 1, 2020 deadline to install avionics capable of broadcasting precise position information, known as automatic dependent surveillance-broadcast out (ADS-B out). While this is not yet an FAA mandate, some regions have imposed requirements for controller-pilot datalink communications (CPDLC) and future air navigation system (Fans 1/A) capabilities. CPDLC and Fans 1/A are datalink communications systems that allow pilots to communicate with controllers via electronic messages instead of voice. Over the ocean, datalink messages are routed via satcom.

Ground to Air

At its core, NextGen involves the transition from a ground-based to an aircraft-based navigation system, explained Steve Fulton, technical fellow at GE’s Naverus business. Fulton, who helped develop RNP procedures while flying for Alaska Airlines, cofounded Naverus, which was later sold to GE. “It’s a higher performance capability,” he said. “We’re no longer constrained to fly paths directly to or from ground navaids; we can create any path we need as the situation desires. There’s a tremendous amount of flexibility in the lateral and vertical paths.”

To make NextGen work, it’s necessary to employ something called performance-based navigation. PBN adds the time element to the three-dimensional path flown by an airplane to create a “4-D” solution, a defined trajectory that can be anything from an approach to an arrival to a full flight from taxi at the departure airport to parking at the destination.

The current system using radar and controllers vectoring aircraft is inefficient, because the time element isn’t precisely planned. Aircraft coming off an arrival procedure are vectored to an ILS first-come, first-served, and each aircraft carves a new path each time. PBN defines the trajectory that the airplane will fly, which includes when and where it will cross particular points in space. With the trajectory defined, Fulton explained, airplanes can arrive from divergent paths and fly to a merge point where they are synchronized into the arrival flow. Because they are using precise RNP navigation and ADS-B to broadcast accurate position, separation can be maintained at a tighter level than with ordinary radar surveillance. This allows for more aircraft to be handled, although airport capacity constraints still limit overall traffic levels. However, NextGen includes airport features such as real-time tracking and display of all aircraft and vehicles, which may help prevent incidents such as the one on April 11 in which an Airbus A380’s wingtip sideswiped the tail of a CRJ700 at JFK Airport.

Surveillance

ADS-B is here, now. A network of ground stations already provides coverage across much of the U.S., including the West and East Coasts, most of the Midwest, the Gulf Coast and a huge chunk of Alaska. Within these areas, properly equipped aircraft can already use some ADS-B services.

Picture ADS-B as an aircraft surveillance operating system, just as Microsoft’s Windows or Apple’s OS X are computer operating systems. With an operating system in place, a computer becomes a platform on which programmers can build useful tools for computer users, such as word processing, spreadsheets, engineering design and so on. Smart companies are already designing tools that play in the ADS-B space and that will provide a benefit to users (aircraft operators and the ANSPs/controllers). These tools are what make NextGen possible, and there is still a lot of experimentation and argumentation under way to select the best tools to run on the ADS-B platform.

It will probably take decades, in fact, to sort this all out. But as the FAA points out in the NextGen Plan, “One of the most difficult challenges is inserting all the NextGen advances, from the simplest to the most complex, into an aviation system that [must continue] to function 24 hours a day, 365 days a year. We cannot shut down the system while we upgrade it. When NextGen capabilities go operational, we will work incrementally. No one will throw a switch that turns on NextGen. Capabilities will come on line gradually. And we take a cautious approach to the infrastructure that enables NextGen advances.”

ADS-B out-equipped aircraft broadcast their identity, position, altitude, speed and other information to ground stations, which in turn send that information to air traffic controllers and to other aircraft. In essence, ADS-B can replace radar and is especially useful in areas where radar coverage is not cost-effective or possible. ADS-B allows for tighter separation between aircraft because information is updated more than once every second, unlike radar, which takes about 12 seconds to complete a sweep and provide an update. During those 12 seconds, a jet can change position by more than half a mile.

To use that information, other aircraft will need ADS-B in equipment, which the FAA has not yet mandated. According to the FAA, “The most basic types of [ADS-B in] enablers provide enhanced situational awareness, improving the ability of the flight crew to identify where aircraft are around them and the direction they are headed.” This information will be displayed on a cockpit display of traffic information (CDTI), which could be integrated with a Tcas display, the FAA noted. Some aircraft, in addition to upgrading to a transponder capable of ADS-B out transmission, may need a GPS sensor upgrade to the latest accuracy standards. After all, no one wants an aircraft broadcasting a position that isn’t highly accurate.

In the U.S., there are two ADS-B frequencies, 1090ES (extended squitter, the same frequency used by mode-S transponders) and 978 UAT (universal access transceiver). Aircraft that fly above 18,000 feet will broadcast their position using 1090ES, while those below can use either 978 UAT or 1090ES. Currently, ADS-B in-equipped aircraft using 978 UAT can receive traffic information and datalink weather and airspace information, for free. Aircraft equipped with 1090ES systems will be able to see traffic on CDTI displays, but the 1090ES doesn’t have the bandwidth to include datalink weather. However, avionics providers are including datalink weather capability in their systems using commercial service providers, but this isn’t free.

For low-altitude operations, it will soon (third quarter 2011) be possible to buy a TSO’d 978 UAT ADS-B transceiver for $4,995 from FreeFlight Systems, providing not only ADS-B out compliance but also access to free weather and ADS-B in traffic information. A company called Radenna makes a $950 UAT ADS-B receiver for the Apple iPad, which works either with Radenna’s SkyRadar or WingX’s moving-map software. For business aircraft, transponders, avionics systems and major upgrade packages include ADS-B out capability, but ADS-B in equipment is not yet ubiquitous.

What Next, FAA?

The big question: when will the FAA begin using all the capability the surveillance part of the NextGen equation offers?

The ADS-B network is scheduled to be complete in both the U.S. and Europe in 2013. The plan is to make some of the more advanced and useful ADS-B tools available starting around then, including in-trail procedures and automation over ocean routes. This means that properly equipped aircraft would be able to climb and descend to more optimal altitudes, in areas where aircraft currently can’t change altitude because of the huge separation standards needed for aircraft that can’t provide information about their precise position.

ACSS, a joint-venture company owned by L-3 and Thales, is doing some interesting work on these tools, and other major avionics manufacturers such as Honeywell, Rockwell Collins and Universal Avionics are developing or have made available some ADS-B capability.

ACSS says it has certified its Tcas with the SafeRoute ADS-B in system to the highest level of ADS-B capability, DO-260B “We’re specializing in ADS-B in and out capability,” said Stephane Chartier, ACSS SafeRoute marketing manager. “That’s a huge component of NextGen.”

ACSS’s equipment is already in use or in the planning stages by companies such as UPS, US Airways, Delta Air Lines and British Airways. UPS is using SafeRoute to track aircraft on the ground and in the air and operate aircraft more efficiently, Chartier said. And later this year, possibly as early as September or October, British Airways, Delta and US Airways will be flying with ACSS TCAS using SafeRoute displaying on Class III EFBs to fly in-trail procedure altitude-change requests on some North Atlantic tracks.

Navigation

For business aviation pilots, especially those who don’t fly outside the U.S., their first exposure to NextGen might be with a new type of instrument approach procedure, called RNP AR (required navigation performance authorization required).

With sufficiently accurate navigation equipment, an aircraft can be guided not only to a precise point at the end of a runway but along a precise path that might look completely different from a standard ILS approach. An added benefit is precisely guided missed approach procedures, too. RNP levels vary, but most new avionics and upgrades offer RNP 0.1 capability, which means horizontal accuracy of a tenth of a nautical mile.

Palm Springs International is a good example of an airport better served by an RNP approach. The sole non-RNP procedure is a VOR or GPS approach, with the lowest MDA at 1,826 feet msl. The RNP (0.3 accuracy required) approach for Runway 31L has a DA of 734 feet msl. And the RNP approach (from certain directions) begins with a big circular turn inside a valley surrounded by mountains. At other airports, RNP procedures feature tricky descending turns that twist around obstacles. An advantage for RNP approach designers is that not only can they adapt the procedure to the local terrain and bring airplanes in much lower (because a precisely tailored missed approach can be created), but they can also design the approach as well as arrival and departure procedures to coexist with elements such as traffic from nearby airports and noise-sensitive neighborhoods.

“We have not seen a lot of business aviation participation [in RNP AR], but there are a number of airplanes becoming capable, so I think that’s changing,” said Naverus’s Fulton.

A key feature of RNP approaches is that they are “authorization required,” meaning that not only is certain equipment needed to fly the procedure but also special training for pilots.

The aircraft needs a flight management computer, autopilot, flight mode annunciator, flight director, EGPWS or Taws, multimode or GPS receiver, large-format displays and additional emergency power source. Pilots need training and a letter of authorization from the FAA. GE Naverus offers services to help operators achieve RNP approval and both GE Naverus and Jeppesen develop RNP procedures for airports.

Jeppesen has developed more about 75 RNP procedures around the world and one in the U.S., at Savannah/Hilton Head International Airport in conjunction with NetJets. “To build one procedure, go through the entire FAA process and have it flight validated would probably be a three-month process,” said Jeppesen’s McDowell. “The proper way is to redesign your entire terminal airspace with RNAV and RNP. If you just do RNP, you’re just building a Band-Aid. You can’t get jumps in capacity until you do a total redesign. On into the future when you have all those components of CNS in place, it opens the possibility of building them dynamically because you have the flexibility of putting waypoints anywhere.

Honeywell, which is participating on the FAA’s NextGen advisory council, has already made NextGen capabilities available on avionics systems in modern Gulfstream (PlaneView) and Falcon (EASy II) cockpits. About 3,000 aircraft equipped with NZ2000 FMS are going to be upgradeable, too, but those with older displays such as Primus 1000 and 2000 systems will need to install Primus Elite LCDs so they can display charts and NextGen graphics.

Carl Esposito, Honeywell leader of marketing and product management, wants operators to understand that NextGen is not just one simple upgrade but rather “a phased implementation and phased capability of technology that improves situational awareness, safety, airspace utilization and overall aircraft/airspace efficiency and productivity.”

To upgrade a Primus 2000 system, for example, the FMS needs to be modified for RNP and Waas LPV capability as well as Fans 1/A, and it also needs the new Primus Elite LCDs to display uplink weather and charts and to provide a platform for later software upgrades that will be needed for eventual NextGen features. Radios need to be upgraded for datalink communications capability and Tcas upgraded for ADS-B out and in. “It is a layered technology and capability approach,” he said. “Depending on the customers’ operating conditions, where they’re flying, whether international or domestic, the flexibility in the upgrade lets them tailor the NextGen capability they need to meet the mission now and upgrade as the mission expands in the future and as NextGen gets rolled out around the world.” Most of this technology is available now from Honeywell or in the final phases of certification, Esposito said. “NextGen is now for Honeywell.”

Rockwell Collins has helped develop NextGen technologies as part of the System Engineering 2020 team led by ITT. The team’s efforts include “concept development work across all dimensions of air traffic control, including ground systems, avionics, aircraft, ATC rules and procedures, human factors, safety and security, environmental and standards.”

More recently, Rockwell Collins announced that the FMS-4200 installed in CRJ700 through 1000 jets’ Pro Line 4 avionics has been upgraded for RNP AR approaches. And the Pro Line 21 upgrade package includes capabilities for future NextGen equipage. The company’s latest avionics suite, Pro Line Fusion, is also designed to accommodate NextGen features.

Universal Avionics is well into NextGen capabilities with its systems, including the Fans 1/A-compliant UniLink 800/801 communications management unit and RNP AR-capable FMSs.

NextGen Benefits

 “When you’re using an aircraft for business purposes, you’re looking for as efficient an operation as you can have,” said Steve Brown, NBAA senior vice president, operations and administration. “Anything that NextGen can do that saves time, reduces fuel burn and lowers emissions is beneficial to the overall mission to transport people in the most efficient way.”

For the near-term, technology that will be part of NextGen already offers operators improved access to airports, via Waas LPV and RNP AR approaches with lower minimums. “It creates some increased capacity at congested airports as well,” he said.

Brown expects to see Waas LPV approaches used for general aviation airports and larger metropolitan airports adopting RNP AR procedures, because of the greater need for the curved flight paths RNP offers where multiple airports have to share the same airspace. Teterboro is an airport in a congested area that could benefit from RNP procedures, and Brown said that one is scheduled for implementation later this year.

Precision GPS-based approaches are just one of the building blocks of NextGen, Brown explained, and the next blocks are already being deployed, with the goal of accommodating growth in air traffic. When ADS-B in becomes available, he added, “There will be a host of weather and traffic information services that will enhance safety.”

While the FAA thus far has not intended that ADS-B in for high-altitude aircraft should include free datalink weather, Brown said that the agency is researching how that could be provided for airline and business aircraft. “The FAA is doing additional research to find out the range limitations within the network,” he said. “It’s partly a product of the spacing of the transmitters.”

For business aircraft operators, there are two ways to approach the NextGen equipment question. “If you have the type of aircraft where avionics are not highly integrated,” Brown said, “you can afford to take a modular approach.” To meet the 2020 ADS-B out surveillance mandate, it’s a matter of swapping in a new transponder. The communications aspect will require new radios. And navigation means an upgraded FMS. For integrated avionics systems, he said, when buying a new system or new aircraft, he advised operators to “make sure you get what you need.”

Join the Movement

ACSS’s Chartier wants to see more business aviation operator involvement in NextGen development. “There are a lot of industry committees that are evaluating different applications around the planet,” he said, “and I don’t think there’s enough of a [business aviation] voice. These things are being evaluated from an airline-centric perspective. We at ACSS are putting the puzzle together for the business jet world and we would like to have the voice of business jet operators be a proponent in this discussion.” 

ACSS is surveying the business aviation community to get operators’ perspectives and to show them what tools such as SafeRoute can do. “Government entities have a lot invested in this,” Chartier said, “and they want the industry to embrace it. They’re willing to play ball, but if you don’t ask, you don’t get.” Business jet operators that show interest in learning about and preparing for NextGen, he added, will get preferential treatment and perhaps even some funding to help pay for upgrades.

FAA Administrator Randy Babbitt underscored the need for all aviation participants to support the move to NextGen in a speech he gave at a symposium held by the Society of Aviation and Flight Educators on May 5. “I know there is a perception that NextGen benefits only big operators,” he said. “The reality is that everyone in aviation stands to gain from NextGen. NextGen bundles dozens of improvements in airports, avionics and ATC. The entire NextGen effort will create a much more efficient, responsive, ‘green’ airspace system that serves the public and supports our national economy.”

Aviation & Systems Integration Group, North Little Rock, Ark., may have put it best in a recent blog post about NextGen: “Don’t fool yourself into thinking that, with the ADS-B out requirement in 2020, that you have a lot of time. Nearly all of the NextGen components—PBN/RNP, ADS-B and datalink communication—are up and running in various parts of the nation. Like rocks of technology strategically dropped into the airspace pool, their rings of operational readiness are growing ever larger.

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