OVERVIEW

Many conclude that the transformation of the US air transportation system is not a matter of technological advances, but merely changes in policy and having the will to transform. While there is certainly truth in that statement, there are also technological challenges that are present. Perhaps one of the largest technological obstacles is the paradigm of control by exception; where the automaton system maintains control of the air traffic until an exception occurs, and the human is reengaged in the loop to solve the exception quickly. The human factors aspects of pulling a human back into the loop for a critical task is not well understood in air transportation, nor many other fields where automation is becoming more autonomous.

The integration of the partner agency missions NextGen is also a challenge. While agencies have interfaces, exchanged information, and worked together in the past, in NextGen their missions are integrated such that, for example, should a security event occur, the situation is quickly identified and appropriate responses are generated to neutralize the event and minimize the overall impact to the National Airspace System (NAS). Such integration is more than information sharing and cooperation.

The notion of having aircraft self-separate from other aircraft is practices today under visual meteorological conditions in selected cases; however, routine delegation of separation under instrument meteorological conditions for large numbers of flights is quite different than delegated separation and it requires extensive research to assure that it can be successfully accomplished in all cases.

As NextGen integrates aircraft, flight operations centers, and the air traffic service providers in a highly automated system that is distributed across those stakeholders, a highly complex, distributed system results. Validation and verification of such a complex system is beyond the state-of-the-art and requires research and analysis to assure that all components of the system are working together and correctly.

Finally, the ability of NextGen to scale and adapt to changing markets and demands is a daunting task. One envisions the use of intelligent systems that are self-adapting to permit NextGen to change scale, accommodate different classes of aircraft, and to meet changing demand. Such systems exist today in science fiction, but are far from reality.

There are several significant technological challenges facing the development of NextGen and research on these aspects should have started long ago. However, as described below, NextGen is off to a slow start.

IMPLEMENTATION

In October 2009, U.S. Department of Transportation Inspector General Calvin Scovel and U.S. Government Accountability Office (GAO) Director of Civil Aviation Issues Gerald Dillingham told Congress that the FAA faced considerable challenges in implementing a satellite-based NextGen ATC system, ranging from delays in approving new procedures and technology to skepticism among airlines regarding investment in new equipment. Testifying before the House of Representatives aviation subcommittee, Scovel warned, "the cost, schedule and benefits for NextGen are uncertain". Dillingham added that the "FAA faces cultural and organizational challenges in implementing NextGen capabilities".

Both said the agency needs to move away from developing Required Navigation Performance (RNP) procedures for airports that merely "overlay existing routes" and toward implementing procedures that allow more direct flight paths that will increase efficiency and lower fuel burn and carbon dioxide emissions. Dillingham said ATC system stakeholders have told GAO "that the process of approving and deploying RNP navigation procedures remains extremely slow and that the FAA's review and approval of a given original RNP design often takes years".

In June 2010, European and American authorities reached a preliminary agreement on interoperability between their future air traffic management systems, SESAR and NextGen. In March 2011, the FAA released the latest version of its implementation plan. As of July 2011, JetBlue and Southwest Airways had installed onboard equipment, partly with federal funds.


According to the FAA the agency is moving forward in a coordinated, integrated manner to deliver the capabilities necessary to enable the agency’s vision for NextGen. Several important milestones are at hand. This section highlights a few of the key NextGen advances the FAA will be working on over the next few years.

ADS-B IN

The FAA last year chartered an Aviation Rulemaking Committee (ARC) to provide a forum for the aviation community to define a strategy for incorporating Automatic Dependent Surveillance-Broadcast (ADS-B) In technologies into the National Airspace System (NAS). ADS-B In capability, combined with a cockpit display, provides greater situational awareness to both high- and low-altitude operators by providing highly accurate traffic. ADS-B In further offers low-altitude users essential flight data such as weather and Special Activity Airspace (SAA) information. The ARC is composed of over two-dozen representatives from various aviation user groups, as well as segments of industry and government. Feedback provided by the aviation community in response to those recommendations will be incorporated into an ARC final report due by June 2012 that will detail suggested next steps.

The ARC’s work will set the stage for future ADS-B In applications, such as spacing and merging aircraft using flight deck interval management. This capability provides more precise aircraft-to-aircraft position information to the flight deck, enabling flight crews to line up their aircraft more efficiently on final approach, saving fuel and maximizing runway capacity. The FAA is currently working with industry on the initial development of flight deck interval management capabilities.

DATA COMMUNICATIONS

Data Communications (Data Comm) will enable digital air traffic control (ATC) information to be exchanged between controllers and pilots, and auto-loaded directly into aircraft flight management systems. This capability will decrease the reliance on voice communication and significantly reduce opportunities for error. On the ground, Data Comm will streamline departure clearances for aircraft sitting at the gate, and provide the ability to transmit revisions to those clearances. In the air, Data Comm will provide for the digital transmission of airborne reroutes. On arrival and landing, Data Comm will enable taxiway and gate assignment information to be sent directly to the flight deck.

A final investment decision slated for 2012 will enable the agency to contract with a vendor to provide the VHF radio network that will carry Data Comm messages. Also moving forward is the development of Controller Pilot Data Link Communications, the application that will facilitate the integration of Data Comm into ATC automation platforms and the aircraft flight deck.

Towers are expected to begin offering departure clearances with revisions to Future Air Navigation System (FANS) 1/A+ equipped aircraft by 2015. En route centers are expected to be able to start issuing airborne reroutes via Data Comm in 2018. This planning date has been adjusted out two years as we continue to weigh the complexity of integrating enhancements into the NAS as well as budget adjustments.

SYSTEM WIDE INFORMATION MANAGEMENT

System Wide Information Management (SWIM) is the network structure that will carry NextGen digital information. SWIM will enable cost-effective, real-time data exchange and sharing among users of the NAS.

In October 2010, the Corridor Integrated Weather System (CIWS) became the first ATC system to share information via the SWIM interface. SWIM compliance means the weather information provided by CIWS to en route center traffic management units can now be made available to external users, such as airline operations centers, to create a common situational awareness. SWIM achieved the same milestone with the Integrated Terminal Weather System in January 2011. By 2015, all seven ATC systems targeted for SWIM’s initial implementation phase are expected to be SWIM compliant.

Throughout 2012, the SWIM program will continue the development work necessary to gather and share airport surface data via SWIM surface information in 2012. By 2013, the SWIM program expects to have standardized its core information delivery service, meaning that custom interfaces will no longer have to be built for programs seeking SWIM compliance.

SPECIAL ACTIVITY AIRSPACE

The FAA is working closely with the Department of Defense (DoD) to improve information sharing on the status of Special Activity Airspace (SAA). Today, the DoD reserves large sections of airspace for mission purposes. Determining when that airspace is safely available for civilian use can be difficult. Being able to take advantage of unused SAA offers the potential to reduce congestion, particularly at peak times.

Between now and 2014, the FAA will continue working with the DoD and industry stakeholders to leverage evolving digital communication capabilities to increase awareness and predictability of SAA usage. Operators will be able to more reliably plan and use flight routes that cross inactive SAA without affecting DoD mission needs. By 2014, the agency plans to have SAA status information integrated into air traffic decision support tools.

CLOSELY SPACED PARALLEL OPERATIONS

Closely Spaced Parallel Operations (CSPO), or dual independent approaches to runways spaced fewer than 4,300 feet apart, hold the promise of getting more aircraft on the ground more quickly in adverse weather conditions.

The FAA is taking a phased, incremental approach to CSPO. Over the next several years, the agency will be working to use existing technology and procedures to improve the efficiency of closely spaced runways. As they move closer to the mid-term and beyond, the FAA will work to leverage advanced technology and Performance Based Navigation.

GOVERNANCE

Two teams of FAA executives, the NextGen Management Board and the NextGen Review Board, constitute a governance structure that works to ensure that the capabilities that grow out of the NextGen portfolio are delivered in a timely, coordinated and cost-effective manner. The NextGen Management Board is chaired by the deputy administrator, the federal official with overall responsibility for NextGen. Composed of the heads of the FAA lines of business with primary responsibility for delivering NextGen, the Management Board provides executive oversight of NextGen progress and performance metrics, and makes strategic policy decisions that drive implementation forward. The Management Board is supported by the NextGen Review Board, which resolves cross-agency implementation issues and identifies and formulates positions on critical policy issues.

The NextGen progress made by the FAA, the goals the agency has set for itself, and the work plan we have committed to in pursuit of those goals are summarized in the NextGen Implementation Plan that is updated annually. The Plan pulls together NextGen information from a number of other key FAA documents. The result is a high-level overview of all the FAA’s NextGen planning and execution efforts in a plain-language document intended to inform a wide audience of NextGen stakeholders.

INTEGRATING NEW CAPABILITIES

NextGen capabilities are not activated all at once. Before the FAA can deliver each new capability, a myriad of activities has to be accomplished, some of which include:
  • safety management system and risk assessments;

  • environmental management system and impact assessments;

  • demonstrations to ensure the capability delivers its intended benefits;

  • tests to determine how the capability affects the workload of FAA technicians, air traffic controllers and pilots;
  • training so that controllers and operators know how to use the capability;

  • identification, development and installation of needed infrastructure and software;

  • development and installation of new aircraft equipment, if needed; and

  • changes to orders and policies to conform to federal and international standards.