Prototype flight management capabilities to explore temporal RNP concepts

A ground-centric concept for merging and sequencing aircraft on Area Navigation (RNAV) and/or Required Navigation Performance (RNP) procedures in the terminal area leveraging the advanced flight deck capability of meeting required time of arrival (RTA) instructions is defined. Automation to provide time-based resolution advisories—RTAs, speed control, and lateral offsets (LOs)—to the controller to achieve efficient merging and sequencing is proposed. Closed-loop simulations using the proposed automation were conducted to assess the viability of the advisory heuristics and to examine coupling dependencies in multiple merge systems.

This pap er presents the development and preliminary results of a trajectory analysis and modeling environment developed in MATLAB and applied to the study of the effects of navigation performance on arrival timing accuracy . This work supports ongoing efforts at The Boeing Company to develop new air traffic management (ATM) concepts and procedures based on accurate navigation standards such as Required Navigation Performance (RNP) and Required Time of Arrival (RTA) . The arrival management concept studied involves th e use of advanced ground automation that perform s sequencing and spacing based on FMS paths rather than relying on controller tactical vectoring . These paths can be defined in three dimensions from prior to top of descent (TOD) to the meter fix and then to the runway , potentially including speed and altitude constraints when needed and would be communicated to the air crew via voice communication and executed to standards (e.g. RNP, RTA) by t he air navigation function embedded in the Flight Management Syste m (FMS). This concept is viewed as a transition step towards the US next generation air traffic system currently being studied by the Joint Planning and Development Office (JPDO).

Nearly 2000 Boeing 737-700 aircraft executing Required Time of Arrival (RTA) operations were simulated using General Electric (GE) Aviation Flight Management Systems (FMSs) with software update 10.7. These flights were examined for RTA time performance as well as compliance with speed and altitude restrictions at the RTA waypoint. Individual flights were paired in post-processing with assigned crossing time offsets of 90 seconds and 120 seconds to characterize spacing behavior of successive aircraft performing RTAs. It was found that aircraft were very successful in meeting RTAs when the winds entered into the FMS were equal to the environmental winds and the RTA windows were accurate. Regardless of wind conditions, the GE Aviation FMS performed well in meeting speed and altitude restrictions at the RTA waypoint. Results show that successive aircraft assigned RTAs with a 90 second or 120 second offset can execute them with a low probability of conflict under certain circumstances.

The differences in performance of various manufacturers' Flight Management Systems (FMSs) and their associated Flight Management Computers (FMCs) have the potential for significant operational impact on the air traffic control system and as such need to be examined on a recurring basis. Performance-based navigation (PBN) is a fundamental principle for aircraft operations that will facilitate the transition to future airspace systems. A critical element of PBN is the FMS's capability to fly a consistently repeatable and predictable flight path trajectory that will meet the expectations of air traffic control. FMS manufacturers build their systems in accordance with and for area navigation systems, Technical Standard Orders and Advisory Circulars. Area Navigation (RNAV) and Required Navigation Performance (RNP) procedures and routes are published by the Federal Aviation Administration (FAA) according to criteria contained in FAA orders. It is anticipated that the resulting performance of the aircraft FMC will meet the procedure design requirements identified in the FAA criteria. Sometimes, due to the nearly independent development of procedure design criteria and aircraft performance standards, the paths of various aircraft on the same procedure do not coincide and therefore do not match the expectations of the procedure designer. These differences may result from any or all of the following: variations in FMC equipment installed on the aircraft; variations and errors in procedure coding in the FMC navigation database; variations in aircraft-to-FMC interface and associated aircraft performance capabilities; and variations in flight crew training and procedures. The hypothesis of this paper is that the FMCs built by avionics manufacturers and installed as the core of the FMC/FMS combinations in various airframe platforms perform differently and we will attempt to quantify those differences. This paper focuses on FMC performance when flying Standard Instrument Departures (SIDs) and their associated waypoints and leg types (path terminators) and combinations as described in. Public instrument procedures flown using RNAV equipment are used as the baseline for measuring the performance variations. Controlled field observations trials were made using twelve FMS test benches and three simulators at seven major FMC manufacturers and two airlines. Analysis of data from the trials confirms differences and the details are presented. The intent of this report is to contribute technical data as a foundation for the acceptance of required navigation performance (RNP) departures.

The purpose of this pilot-in-the-loop aircraft taxi simulation was to evaluate a NextGen concept for surface trajectory-based operations (STBO) in which air traffic control (ATC) issued taxi clearances with a required time of arrival (RTA) by Data Communications (DataComm). Flight deck avionics, driven by an error-nulling algorithm, displayed the speed needed to meet the RTA. To ensure robustness of the algorithm, the ability of 10 two-pilot crews to meet the RTA was tested in nine experimental trials representing a range of realistic conditions including a taxi route change, an RTA change, a departure clearance change, and a crossing traffic hold scenario. In some trials, these DataComm taxi clearances or clearance modifications were accompanied by 'preview' information, in which the airport map display showed a preview of the proposed route changes, including the necessary speed to meet the RTA. Overall, the results of this study show that with the aid of the RTA speed algorithm, pilots were able to meet their RTAs with very little time error in all of the robustness-testing scenarios. Results indicated that when taxi clearance changes were issued by DataComm only, pilots required longer notification distances than with voice communication. However, when the DataComm was accompanied by graphical preview, the notification distance required by pilots was equivalent to that for voice.

4D-trajectory-based operations (where D stands for dimensional) are proposed by SESAR and NGATS as the fundamental cornerstones of air traffic management (ATM) system improvements of the future. Various research initiatives such as PHARE (M. Van Gool and H. Schroter, 1999) have long described and prototyped these ideas of integrated air-ground ATM. However, because the broad implementation of this concept requires significant harmonized development of both air-and ground-based technology, progress has been limited. Nonetheless, the avionics industry has implemented initial capabilities to manage the fourth dimension, i.e. time, called required time of arrival (RTA). The paper summarizes the results obtained from a EUROCONTROL study on the availability, characteristics and performance of the required time of arrival (RTA) function in existing flight management systems (FMS). The RTA study is first discussed in the context of ATM, proposing some guiding premises as to how the time management function should be developed. As a consequence, the RTA study focused on performance during descent, using different FMS modes. A brief discussion of related EUROCONTROL projects has also been added. Test results from a number of sessions on Boeing 737 and Airbus A320 flight simulators are then presented. The evaluation included an assessment of the impact of wind on RTA, as well as some observations about the human machine interface aspects. Lastly, conclusions and recommendations for further development are proposed.

The differences in performance of various manufacturers' Flight Management Systems (FMSs) and their associated Flight Management Computers (FMCs) have the potential for significant impact on the air traffic control system and as such need to be examined and reexamined. While Performance-Based Navigation (PBN), Area Navigation (RNAV) and Required Navigation Performance (RNP) procedures and routes are designed according to criteria contained in Federal Aviation Administration (FAA) orders, FMC manufacturers build their systems in accordance with Minimum Aviation System Performance Standards (MASPS) and Minimum Operational Performance Standards (MOPS) for area navigation systems, Technical Standard Orders (TSOs) and Advisory Circulars (ACs). With the exception of some minor differences, it has been shown in previous research on this subject that the resulting performance of the aircraft FMC will generally meet the procedure design requirements identified in the FAA criteria.

This paper describes a Traffic Flow Management stochastic optimization model that exploits increased navigation performance. The model integrates Traffic Flow Management strategies and avionics capabilities for the Next Generation Air Transportation System. It generates Traffic Management Initiatives that are designed to improve National Airspace System performance and considers best-equipped best-served prioritization schemes. This work extends previous approaches by considering Required Navigation Performance levels in the Super-Dense Operations airspace with probabilistic weather scenarios to minimize ground and en route holding delays. The paper also presents results of simulation experiments in which the feasibility of the optimization model was evaluated using several scenarios for a Super-Dense Operations problem around Chicago, including varied demand levels, Required Navigation Performance equipage distributions, and weather scenarios. The results show that without improved navigation performance system delays may increase up to five times with the expected threefold demand growth. Simulations also showed that the majority of delays may be eliminated with improved Required Navigation Performance equipage and Traffic Flow Management algorithms properly exploiting increased navigation performance.

SESAR is Europe's ‘Single European Sky Air traffic Research system’. NextGen is the USA's ‘Next Generation Air Transport System’. SESAR and NextGen are developments targeted at post 2020. The common vision is to integrate and implement new technologies to improve air traffic management (ATM) performance – a ‘new paradigm’. SESAR and NextGen combine increased automation with new procedures to achieve safety, economic, capacity, environmental, and security benefits. The systems do not have to be identical, but must have aligned requirements for equipment standards and technical interoperability.A key component is a ‘cooperative surveillance’ model, where aircraft are constantly transmitting their position (from navigational satellites), flight path intent, and other useful aircraft parameters – known as ADS-B (Automatic Dependent Surveillance-Broadcast). The focus for planning and executing system operations will increasingly be aircraft 4D trajectories: a 4D trajectory is the aircraft path, three space dimensions plus time, from gate-to-gate, i.e. including the path along the ground at the airport.In analysing potential major ATM system changes, a simple division into five Key Test areas might be: Safety Credibility, Operational Concept, Technological Feasibility, Benefits and Costs, and Transition Path. The main attention here is on Benefits and Costs of SESAR. The strategic challenge will be to convince customers and stakeholders of the benefits of paradigm shift expenditure, given the associated impacts on future user charges, aircraft equipment investments and public expenditure. The analysis here shows that the existing cost benefit analysis results for SESAR are not particularly robust, possibly over-estimating Net Present Values by some tens of € billions.

This paper describes a modular flight management system for unmanned multicopters, small unmanned fixed wing vehicles, vehicles used in Urban Air Mobility concepts, helicopters and other VTOL vehicles. With the expected growth in traffic of these types of vehicles especially in the urban environment it is necessary to generate reliable precalculated 4D trajectories for these vehicles. Furthermore, some of these vehicles need additional guidance to keep them on the precalculated path.The second central use case for this system is the fast trajectory calculation for fast and real time traffic simulations with a broad variety of vehicles, especially vehicles which are not covered by conventional flight management and trajectory generation systems.To solve these requirements, the system precalculates precise 4D trajectories for classic and experimental mission designs. These trajectories are tested for safety and continuity by a separate module and could then be executed on the corresponding vehicle (or a simulation) with the use of a guidance module.To calculate this huge variety of vehicles with different means of propulsion, the vehicle performance is kept in a separate module. This allows the system to not only work with different vehicle types, but also to switch between different vehicle configurations with considerable changes in the vehicle’s performance and behavior.Some of the targeted vehicles only exist in an earlier design stage or do not provide details performance information. Thus, the performance module is able to work with very simple performance modules based on early design conditions as well as detailed performance models based on exhaustive knowledge of the vehicle’s physical behavior.As the flight behaviors could change between the vehicles and their corresponding performance types, not all vehicles could use the same flight phases. Different parts of the trajectory are designed by different modules which specialize in the design of a specific flight phase. The performance module holds the information which flight phase could be applied on the vehicle and the corresponding boundaries. The system includes conventional flight phase modules for takeoff, cruise and landing and the transition between these phases as well as some specific flight phases, such as following waypoints relative to a moving target.The central trajectory management module then coordinates the different flight phases and ensures a continuous trajectory. This module also adds flight phases where required to guaranty a smooth transition between the different phases.Finally, this paper will show some example implementation of this system into traffic simulations and vehicle simulations.

The introduction of automated flight control and management systems have made possible aircraft designs that sacrifice arodynamic stability in order to incorporate stealth technology intro their shape, operate more efficiently, and are highly maneuverable. Therefore, modern flight management systems are reliant on multiple redundant sensors to monitor and control the rotations of the aircraft. To this end, a novel distributed quaternion Kalman filtering algorithm is developed for tracking the rotation and orientation of an aircraft in the three-dimensional space. The algorithm is developed to distribute computation among the sensors in a manner that forces them to consent to a unique solution while being robust to sensor and link failure, a desirable characteristic for flight management systems. In addition, the underlying quaternion-valued state space model allows to avoid problems associated with gimbal lock. The performance of the developed algorithm is verified through simulations.

The New York (NY) area airspace is notoriously complex and demanding, and is responsible for a large portion of the delays and congestion in the United States. A new research effort was initiated to examine the chronic problems associated with NY, and to develop integrated Next Generation Air Transportation System (NextGen) concepts that leveraged existing NASA and other NextGen technologies to reduce delays, increase throughput, and/or improve trajectory efficiencies in this region. This paper describes a concept, tools, and operational procedures for improving flight efficiency and runway throughput for Newark Liberty International airport (EWR) arrivals. The concept increases throughput by extending the Terminal Sequencing and Spacing (TSS) scheduling capability to precisely schedule runway 11 arrivals behind arrivals landing on intersecting runway 22L, thereby maximizing throughput on both runways. A human-in-the-loop (HITL) evaluation of the concept indicated that TSS can enable more energy efficient, trajectorybased optimized profile descent procedures to be used without sacrificing throughput, even in the very challenging New York environment. In addition, the results suggest that the enhancements to TSS to coordinate the threshold times of aircraft landing on converging runways could safely increase throughput for EWR from today’s Visual Flight Rules (VFR) maximum of 52 to 67 arrivals per hour. A follow-up benefits analysis was conducted to identify how often meteorological conditions were suitable for using the 11-22L landing runway configuration, and estimate the actual resulting potential for increasing arrival throughput. Aviation System Performance Metrics (ASPM) data were used to determine the traffic demand, runway configurations, meteorological conditions, and wind magnitudes/directions during 2007, 2009 and 2012. Using fairly conservative assumptions about the meteorological conditions, runway usage, and peak demand characteristics, the analysis showed that the 11-22L runway configuration could have been used more than twice as often during high demand periods (arrival demand exceeds throughput), which in turn could either 1) reduce delays to the impacted aircraft by approximately 15 minutes per aircraft or 2) increase the overall throughput by approximately 8% 11% per year. This new operation has the potential to deliver even greater benefits if it were extended to include other runway configurations and demand conditions. The results suggest that a large throughput / delay benefit can be gained from a modest extension of the TSS tool that is already in the Federal Aviation Administration's planned new capabilities by 2020.

To meet the growing demands of the National Airspace System (NAS) stakeholders and provide the level of service, safety and security needed to sustain future air transport, the Next Generation Air Transportation System (NextGen) concept calls for technologies and systems offering increasing support from automated systems that provide decision-aiding and optimization capabilities. This is an exciting application for some core aspects of Artificial Intelligence research since the automation must be designed to enable the human operators to access and process a myriad of information sources, understand heightened system complexity, and maximize capacity, throughput and fuel savings in the NAS.. This paper introduces an emerging application of techniques from mixed initiative (adjustable autonomy), multi-agent systems, and task scheduling techniques to the air traffic control domain. Consequently, we have created a testbed for investigating the critical challenges in supporting the early design of systems that allow for optimal, context-sensitive function (role) allocation between air traffic controller and automated agents. A pilot study has been conducted with the testbed and preliminary results show a marked qualitative improvement in using dynamic function allocation optimization versus static function allocation.

Next generation flight management systems require the compliance of temporal and spatial constraints on navigation performance. The problem of generating fuel-efficient trajectories for aircrafts that comply with the required navigation performance is approached from an optimal control framework. By deriving the necessary conditions for optimality, nominal optimal control signals can be generated in a computationally efficient manner. These control signals can be used to generate nominal trajectories for an aircraft model. Using the nominal control and nominal trajectory, a feedforward-feedback control scheme can be implemented to robustify the system's response in the presence of uncertainty and disturbances to still achieve the required navigation performance. The feasibility of the approach is demonstrated through simulation and Monte Carlo runs.

Air Force Air Mobility Command (AMC) aircraft must meet military requirements for transport missions anywhere in the world while also addressing emerging Civil Aviation Authority requirements for Communication, Navigation and Surveillance (CNS) for operation in the Global Air Traffic Management (GATM) environment. An architecture designed to meet these requirements must accommodate existing avionics to the maximum extent possible to minimize costs and must also incorporate new avionics that take advantage of Commercial Off The Shelf (COTS)/Non Developmental Items (NDI) and open system architectures to be able to incorporate the growth necessitated by these emerging requirements. This paper describes a generic architecture designed to meet these requirements for a tanker/transport platform. The architecture is designed so that future upgrades for these evolving requirements could be met with minimal impact to the aircraft. The implementation of this architecture is primarily a systems engineering effort in managing the human machine interface necessary to provide a seamless integration of GATM and navigation safety equipment including an Enhanced Ground Proximity Warning System (EGPWS), a Communication Management Function (CMF), a Multi-Mode Receiver (MMR), a traffic collision and avoidance system (TCAS), new communications radios, a new displays subsystem and existing flight management systems that are modified, as necessary, to support Required Navigation Performance (RNP) objectives.