With safety management systems deemed essential in aviation, suggestions that risk analysis takes too long would seem out of line. In the context of accelerating implementation of the Next Generation Air Transportation System (NextGen) in the United States, however, the streamlining of risk analysis emerged as one of several safety-related issues raised by 50 speakers and panelists at the RTCA Spring Symposium, held April 6–7 in Washington, with about 350 attendees from the aviation industry and the U.S. Federal Aviation Administration (FAA).
The event also covered issues such as global compatibility of technology, incentives for air carriers to equip aircraft, business cases, and political and environmental constraints.
Most of the symposium was devoted to how the FAA has adopted 28 recommendations of the 300-member RTCA NextGen Mid-Term Implementation Task Force, also called Task Force 5, which were issued in September 2009 and incorporated into the FAA NextGen Implementation Plan of March 2010.
Basically, NextGen is a comprehensive overhaul of the U.S. National Airspace System (NAS), which is already beginning to add capabilities that make air transportation safer and more reliable, increase the air traffic capacity of the NAS, and reduce the impact of aviation on the environment, the FAA says. Details of the next phase of formal interaction between the FAA and industry will be announced in May by the FAA NextGen Management Board.
“We can’t afford not to move forward with NextGen,” FAA Administrator Randy Babbitt told the symposium participants. “Let me say with emphasis: NextGen is under way. We are en route. We are not in the planning stages. We are airborne with this, and we can’t afford to lose time. We need NextGen now and ‘now’ as in right now.”
The FAA wants to capitalize on a period when the number of aircraft and operations are down — even though passenger traffic, load factors and aircraft capacities are higher — to massively upgrade aviation infrastructure. “We don’t want to wait until capacity gets back to maximum,” Babbitt said.
FAA acceptance of most task force recommendations signifies a critical consensus about mutual priorities, he added. “Now we are all tracking to true north on the same compass,” he said. “RTCA has collectively given the FAA the priorities that we need to set — like implementing closely spaced parallel approach sequencing and, for operations at critical airports, going as far as integrated traffic management.”
The task force generated a level of industry commitment that — assuming it holds together — should lead to successful NextGen implementation, said Margaret Gilligan, associate administrator for aviation safety, FAA. “But if we start seeing breakoffs of individuals or subgroups … that would be very detrimental,” she said.
Sandy Samuel, vice president of transportation solutions, Information Systems and Global Services, Lockheed Martin, distilled a key industry concern. “From the data communications perspective, we could lay the whole infrastructure in place, but we know there’s this big public policy decision to be made about who should pay for [aircraft] equipage,” Samuel said. “I don’t really think it [could] be the technology that delays NextGen. I think it could be [making] some of the hard policy decisions … before we get too far down the implementation path and then have to start over or stop altogether.”
Safety Perspectives
Brian Townsend, a captain in flight technical operations at US Airways, characterized the new NextGen Implementation Plan as “heavily weighted toward research and data collection.” He expressed concern about potential duplication of effort in the name of safety. “We need to use a lot of the information that we have,” Townsend said. “We certainly don’t want to skip over the safety aspect — that’s extremely important to maintain in focus before we take the necessary [implementation] steps — but at some point we do have to take the plunge. We also need to take a very close look at the safety risk management process and make certain that, in some respects, it’s not hindering some of the progress even though it’s a very important component. From some of my observations and experiences, at times it can really tend to hold us back.”
Operators bear the ultimate responsibility for safely moving passengers, crews and cargo, said Rip Torn, a Delta Air Lines captain and chairman, Air Traffic Services Group, Air Line Pilots Association, International. “No one will say, ‘We need safety to be the second, third or fourth [priority],’” he said.
U.S. aviation has a long track record of identifying human-in-the-loop risks early by thorough study before implementing changes to the NAS, Torn said. “Once a safety study is done and we start trapping the errors and coming up with risk mitigations, we get buy-in — people want to stick their toes in the water and try new procedures,” he added.
Bruce DeCleene, manager, avionics systems, FAA, said NextGen activities have been a major challenge so far for FAA aircraft certification offices. “We are resource-limited,” DeCleene said. “There have been times when installation of these technologies had to sit while we worked on other higher-priority projects. We are putting in place a change to our prioritization criteria so that our highest-priority projects will always be safety-related, such as something based on an airworthiness directive or something unsafe. Then, immediately beneath that, there will be the alterations to an aircraft in support of a national NextGen-related initiative.”
“Safety is not going to be one of our biggest challenges because we are all unified in purpose. … A bigger challenge actually is complexity … from trying to tailor solutions to individual stakeholders, operators, etc. — which increases how many different solutions there are [and] how many different solutions have to be managed and monitored in the system. It’s critical to recognize that we have to try to keep things simple.”
The key to full industry support of NextGen implementation will be definable benefits that must begin to be shown “this year or very soon,” said Ken Speir, a captain and Atlanta chief pilot at Delta. The industry wants to see teams assigned to — that is, 23 multi-airport urban areas anchored by the nation’s 35 busiest airports — begin their work without delay, he added.
Risk analysis under safety management systems and environmental impact studies ranks high among the aviation community’s concerns, Speir added. “I don’t know how we will get through the safety-management activities, as well as the environmental issues, to really get everything that we need to get out of NextGen. But this is the most optimistic that I have been in more than 10 years.”
Real-world implementation will reveal unanticipated safety issues, he said. “I was very involved in the area navigation [RNAV] implementation in Atlanta, for example,” Speir said. “Never in a million years would we have believed [before implementation] that the no. 1 obstruction to RNAV off the runway or RNAV standard instrument departure [SID] and standard instrument arrival [STAR] applications actually was the pilot putting the correct runway into the flight management system [FMS]. If we can’t do RNAV off the runway today, how are we ever going to make the NextGen of 2018 a reality?”
FAA Air Traffic Organization (ATO) terminal personnel in Atlanta told the National Air Traffic Controllers Association (NATCA) that FMS programming errors by pilots have led to 13 turning errors out of 250,000 RNAV off the runway departures, responded Dale Wright, NATCA’s director of safety and technology. “What [the errors] boiled down to was that runways were changed, and the pilots had the RNAV [procedure in the FMS] but did not have the correct runway in [the FMS],” Wright said. “[Atlanta tower] controllers are keeping their airplanes on their frequencies longer and making sure pilots turn the right way, or they ensure pilots are on the right departure.
“Typically, most of the performance-based navigation [PBN] errors we’ve had … have been a gradual conflict, very controllable, [because of inherent] increased levels of safety as opposed to errors that might have been more drastic in the ‘pre-PBN’ world.”
NATCA is committed to implementing NextGen and has been working to convince its members that far-reaching changes actually will happen in the near future, Wright said. Consistent, thorough and complete training of controllers will be essential, he noted.
“So many times, RNAV approaches and required navigation performance [RNP] approaches have been put into an area like New York but when the pilot flies into Newark and says, ‘I’d like the RNAV 29,’ the controller says, ‘What’s that?’” Wright said. “That’s because the controllers haven’t been briefed. We have to improve that. We have a new workforce. They want to learn. We need to teach them.”
While controllers need to be trained appropriately, they also need confidence that the pilots in their airspace have been trained to correctly conduct RNAV and required navigation performance (RNP) procedures. Air traffic control (ATC) also needs to be able to determine, from a glance at tags accompanying aircraft targets on their displays, how aircraft are equipped for NextGen capabilities. “That way, the controller remains focused on the scopes, not looking around with attention diverted,” Wright said.
Speir added that during transition from NextGen demonstrations to initial operating capability, temporary differences in controller phraseology require safety mitigation through notices to flight crews. A Delta bulletin distributed April 5 to flight crews flying in and out of LaGuardia, for example, targeted a new SID with RNAV off the runway and associated speed and altitude restrictions. The notice said in part, “For takeoff clearances in LaGuardia, controllers will use standard phraseology ‘Delta 123, Runway 13, cleared for takeoff.’ LaGuardia tower will not use the Atlanta RNAV off the runway takeoff phraseology, which includes the initial fix on the RNAV departure, for example ‘Delta 123, RNAV to FUTBL, cleared for takeoff, Runway 27R.’ The clearance language used in Atlanta is a trial program for future implementation across the United States, but for now, only Atlanta and Dallas/Fort Worth use that phraseology.” Speir said that this inconsistent phraseology has been in place for three years.
Written consensus about launching metroplex-level teams is tangible evidence of progress, said Chris Oswald, vice president, safety and technical operations, Airports Council International–North America. “We will have multiple [metroplex] test beds — whether two or five or 10 initially — and ways to adjust what we are doing with NextGen to reflect real-world, local situations, such as the ways that runway flow configurations operate in a particular metroplex,” Oswald said.
“The safety risk management piece … is essential, but we need to approach it realistically. How much time is that really going to take as we get into each of these metroplexes? Are there ways that … those processes can be streamlined without compromising safety? You can’t model all of the airport detail, all of the weather conditions or all the flow configurations.”
Metroplexes and Misalignments
The following examples show how the few gaps and misalignments between the task force recommendations and the FAA’s latest implementation plan shaped the discussions. The recommendation that called for the agency to integrate and optimize airspace and procedure design at a task force–identified subset of metroplexes seeks traffic deconfliction of airports, RNP with radius-to-fix capability (that is, curved flight paths) and expanded use of ATC terminal separation, said Gisele Mohler, manager, airspace and PBN integration, ATO System Operations, FAA.
Metroplexes became such a major focus of task force efforts because of delays and inefficiencies that have developed where multiple airports in close proximity compete for the same airspace, and traffic loading and flow imbalances exist across egress and ingress routes, runways and city pairs, explained Lillian Ryals, director, system operations, safety and performance, The MITRE Corp.
Among locations considered NextGen proving grounds, Ryals cited RNAV at Atlanta-Hartsfield International Airport; optimized profile descents at Phoenix Sky Harbor Airport in Arizona; integrated airspace and routes built around an optimal set of RNAV SIDs and STARs at Denver International Airport; advanced aircraft equipage for PBN at Chicago O’Hare International Airport, including RNP applications to prevent conflicts among Chicago Midway Airport arrivals and O’Hare departures; and expedited west gate departures with higher and faster initial climb in the New York metroplex.
“Metroplex-related recommendations call for automation that helps controllers in metering, monitoring and merging traffic along RNAV arrival routes,” Ryals said. “We also understand that metroplex operations are interconnected end to end across all phases of flight, including surface operations, access to airport airspace and runways, and cruise and cross-cutting capabilities [that is, leveraging integrated air traffic management and data communications].”
Victoria Cox, senior vice president, NextGen and Operations Planning Services, FAA ATO, noted why metroplex selection is pending. “We do intend to identify specific locations, but … we’ve got to conduct business and safety assessments of capabilities. … Some of the recommended locations for some capabilities, particularly locations with low traffic volume, may not prove to be cost beneficial and may not get selected for implementation.”
The FAA’s Mohler emphasized that the agency will move forward “expeditiously and prudently” on establishing the metroplex teams, however. Over roughly a 24-month period, each team will have a common toolbox; a subgroup that quantitatively and qualitatively assesses current operations, and explores potential improvements; and a decision-making subgroup. The second subgroup will prioritize NextGen changes based on the assessment, available resources and constraints, then select target activities for FAA design and implementation teams.
Elizabeth Lynn Ray, director, airspace and aeronautical information management, FAA, cautioned against expecting perfectly implemented NextGen capabilities in metroplexes. “We are not going to get a perfect answer for every metroplex but collectively … we will come up with a 75- or 80-percent solution that will multiply over time. From the airspace and PBN perspective, this metroplex work easily could be 75 to 80 percent of the entire [NextGen] work plan.”
Reworking Parallel Operations
In response to the recommendation for increased use of parallel, staggered and converging runway operations, the FAA is upgrading ATC displays with runway path indicators, a major software change to terminal operation systems that will provide greater benefits but over a longer time than requested, said Leo Eldredge, manager, Global Navigation Satellite System Group, ATO Technical Operations, FAA. The FAA also will begin the phase-in of closely spaced parallel operations, including staggered approaches, at Newark, Memphis and Seattle, and will investigate Washington Dulles International Airport and Denver.
“Flying airplanes close together on final approach is subject to what the blunder of one aircraft [pilot] can do to the other aircraft flying in parallel operations,” Eldredge said. “We need to assess the model used today, bring it up to date to current operations and improve the navigation performance of the aircraft. What we did 20 years ago may prove to be more conservative than what we could accomplish based on the best knowledge today, or it may not. There is no guarantee that there will be a positive outcome [from analysis under] a newer target level of safety.”
One related recommendation called for using multilateration — that is, determining aircraft position using time difference of arrival of transponder signals at multiple antenna sites — as a replacement or substitute for ATC precision runway monitoring radar to enable closely spaced parallel operations. “We are going to collect [proprietary Detroit, Michigan,] data and also look at Atlanta as a possible source of data, and have a business case established before we take the next step to establish multilateration as an FAA program,” Eldredge said.
Agency work on these ideas had begun even before the 2009 task force was convened, the FAA’s Gilligan said, noting, “Clearly, technology offers us the opportunity to make the safety case for a closer spacing between parallel runways — safely. … We have taken a scientific approach, collecting new data, and trying to better understand the issue of pilot blunder, how that plays [into risk] and how we can be sure we can protect the airspace necessary to assure the level of safety that we have presently. At the same time, we’ll look at whether the distances that we have set now are necessary. Whether they come down to a 700-ft [213-m] standard — I don’t know yet.”
Another recommendation sought to establish satellite-based navigation as equivalent to an instrument landing system (ILS) for purposes of widely and closely spaced runway operations. “There are over 2,000 LPV [localizer performance with vertical guidance] approaches and over 4,000 global positioning system–based RNAV approaches in the NAS today,” the FAA’s Eldredge said. “Our plan is to complete the safety risk management this year, and to do it as fast as we can.”
The task force recommendation for one person at the FAA to be assigned overall responsibility for NextGen, which the FAA is considering, has a serious safety component — it was not just a matter of simplified communication or convenience for the aviation industry, said Steve Vail, senior adviser, air traffic operations, FedEx Express. Specifically, transfer of knowledge from a number of past FAA technology demonstrations and special projects proved to be inadequate, he said.
“We have had a commercial off-the-shelf product in use [for surface management] by Northwest/Delta at Detroit and Minneapolis,” Vail said. “We have had a U.S. National Aeronautics and Space Administration product in use at Memphis [Tennessee] and Louisville [Kentucky]. Now we’ve got pushback control using another tool at John F. Kennedy International Airport. They have [yielded] valuable data about runway queuing and reducing taxi time, but we haven’t been able to transfer them to [other airlines] or to other airports. We are starting from ground zero at every airport.”
Rowena Mendez-Ruano, NextGen engineering manager, ATO En Route Program, FAA, said that the agency has a program ready to expand the use of time-based metering at metroplexes — including new procedures and related air traffic controller training — pending acceptance of safety cases and business cases. Another recommendation, to implement required time of arrival procedures at the metroplex level, so far remains in the “initial stages of concept development,” she said. Regarding more Q and T en route systems — the RNAV equivalents of conventional high-altitude and low-altitude instrument routes, respectively — she said the FAA has begun collaborating with the industry on a strategy linked to pending decisions about the metroplex order of priority for NextGen implementation.
Non-Movement Area Surveillance
Kip Spurio, system engineering manager and chief system engineer, ATO Terminal Services, FAA, told the symposium participants that the recommendation to initiate surveillance in the non-movement areas of airports is being studied in light of the FAA’s deployment of other surface-surveillance systems and its new capability for data dissemination. Although the technology itself probably could be available quickly, still unresolved is the FAA’s policy on distributing such surveillance data to airlines, airports and other potential users.
“There are a lot of questions around data release,” added Teri Bristol, vice president, technical operations services, FAA. “Near-term, we’re making changes to [FAA Order 1200.22D, “FAA National Airspace System (NAS) Data and Interface Equipment Used by Outside Interests”] to streamline [decisions] in the environment we are in today. There are a lot of different classes of users, and different people need information for different things. We also follow processes that determine how we share data, how we release data and who needs access to data.”
Surveillance cannot be introduced in some metroplexes as recommended, however, said Stephen Ryan, senior system engineer, ATO Terminal Services, FAA. Aside from the unresolved data-sharing policy, the reason is that the FAA first will have to complete its 2012–2018 mid-term roadmap of air traffic management capabilities and upgrade its traffic flow management system. This is the same system that later will introduce electronic negotiation of flight paths between aircraft pilots and ATC. Nevertheless, the FAA agreed to work on data-sharing frameworks.
The recommendation to optimize data communications before 2012, as well as in the 2012–2018 midterm, called for introducing advanced en route and terminal capabilities that capitalize on existing aircraft equipage standards. One example is tailored arrivals at coastal airports — that is, descent procedures that can be customized for a specific aircraft and current weather conditions. FAA investment decisions are pending and will be followed by a tower datalink upgrade, modifications of the existing en route automation modernization contract and testing, Ryan said. For tailored arrivals, a process to identify changes to ground automation systems has been scheduled.
Feature image: © Manas Barooah | Airliners.net