Showing papers on "Required navigation performance published in 2011"

Agent-Based Cooperative Decentralized Airplane-Collision Avoidance

Abstract: The efficiency of the current centralized air-traffic management is limited. A next-generation air transportation system should allow airplanes (manned and unmanned) to change their flight paths during the flight without approval from a centralized en route control. Such a scheme requires decentralized peer-to-peer conflict detection and collision-avoidance processes. In this paper, two cooperative (negotiation-based) conflict-resolution algorithms are presented: iterative peer-to-peer and multiparty algorithms. They are based on high-level flight-plan variations using evasion maneuvers. The algorithms work with a different level of coordination autonomy, respect realistic assumptions of imprecise flight execution (integrating required navigation performance), and work in real time, where the planning and plan-execution phases interleave. Both algorithms provide a resolution in a 4-D domain (3-D space and time). The proposed algorithms are evaluated experimentally, and their quality is studied in comparison with a state-of-the-art agent-based method-the satisficing game theory algorithm.

Evaluation of the Potential Environmental Benefits of RNAV/RNP Arrival Procedures

Abstract: Improving aircraft operational procedures is one strategy that can be used to mitigate aviation’s environmental impacts in relatively short time-frames with existing aircraft types. This study quantifies the potential environmental benefits achievable with operational changes in Area Navigation (RNAV) and Required Navigation Performance (RNP) departure and approach procedures using a case study of approaches at SEATAC. Results indicate that properly designed RNAV/RNP procedures can yield fuel and emissions savings during approach of up to approximately 40 percent. However, the maximum benefits are only realized when procedures are optimized to improve environmental and operational performance. “Overlay” RNAV procedures, which are merely higher precision versions of existing non-RNAV procedures, often do not yield much fuel benefit or deliver any meaningful noise impact reduction.

Required navigation performance authorization required

Abstract: The article deals with the concept of required navigation performances and also the concept of RNP AR APCH. The main exploitation preferences and benefits are considered according to the safety of aviation. Efficiency and safety of the given specification usage are argued

Method and device for aiding the managing of air operations with required navigation and guidance performance

Abstract: The device aids the management of air operations, such as operations under Required Navigation Performance with Authorization Required maneuvers. The device includes a guidance system including a plurality of stages for calculating parameters, each of the stages including an architecture having at least three pieces of equipment, which calculate the parameters and implement monitorings to determine the status of the equipment. The device uses these monitored statuses to determine a global status that indicates if the aircraft is able to carry out the air operations with required performance.

Analysis of Advanced Flight Management Systems (FMS), Flight Management Computer (FMC) field observations trials: Area Navigation (RNAV) holding patterns

Abstract: 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 require continuous examination. While 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 design their systems in accordance with Minimum Aviation System Performance Standards (MASPS) and Minimum Operational Performance Standards (MOPS) for area navigation systems, Technical Standard Orders and Advisory Circulars. It is anticipated that the resulting performance of the aircraft FMC will meet the procedure design requirements identified in the FAA criteria. The resulting variation however has posed a challenge for the criteria development and Air Traffic operations. A goal of this paper is to provide supporting data for the development of instrument flight procedures where aircraft operations meet expectations for repeatability and predictability to levels of performance sufficient to support Performance-based Navigation (PBN) worldwide and specifically in the National Airspace System (NAS) and the Next Generation (NextGen) environment. 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 overlap and do not match the intent of the procedure designer. This paper is a continuation of five studies, beginning in 2006, (all presented at previous Digital Avionics System Conferences) with the basic title of Analysis of Advanced Flight Management Systems (FMSs), FMC Field Observations Trials. They have shown that 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 the major avionics manufacturers and installed as the core of the FMC/FMS combinations in various airframe platforms will perform differently with respect to the construction and execution of holding patterns. The paper will attempt to identify and quantify those differences. As airspace becomes more complex, the use of RNAV and RNP holding patterns will become increasingly more important as a tool to reduce the size of holding protected areas. Today, there are no FAA criteria for RNP holding and there are many questions unanswered about RNAV holding. Some of these questions relate to how FMC's build a holding pattern path, how they compute holding pattern entries, how the FMC computes holding pattern time, and how they determine miles from the holding fix for a Distance Measuring Equipment (DME) hold. Controlled field observations trials were completed using fourteen FMC avionics test benches at seven major FMC manufacturers and two high fidelity flight simulators at a major airline. This year's analysis of holding patterns follows The MITRE Corporation's previous analyses of FMC lateral navigation (LNAV), vertical navigation (VNAV), radius-to-fix (RF) path conformance, lateral and vertical path integration and RNAV off the ground Standard Instrument Departures (SIDs). The intent of this report is to contribute data, analysis, conclusions and recommendations to industry and the FAA that may influence criteria development to enhance RNAV and RNP operations.

Modeling of Traffic Management Advisor as a Baseline for the Assessment of Metroplex Time-based Scheduling Concepts

Abstract: When assessing NextGen metroplex time-based scheduling concepts there is a need for a current-day baseline to compare their performance against. In the current air traffic system, the Traffic Management Advisor (TMA) is a decision support tool (DST) that assists the Center Traffic Management Coordinators (TMCs) and controllers with planning and time- based scheduling of arrival traffic. TMA is a part of a suite of DSTs developed by the National Aeronautics and Space Administration (NASA) called the Center-TRACON Automation System (CTAS). TMA is currently installed and functional at all 20 Air Route Traffic Control Centers (ARTCCs) in the U.S. TMA's time-based scheduling engine, called the Dynamic Planner (DP), is the current state-of-the-art in multi-airport time-based arrival scheduling controller aids. TMA's DP can handle up to five different airports within a TRACON and treats them as separate entities from the scheduling perspective. This paper discusses the development of a proxy model of TMA's DP scheduling capability and its application to the assessment of one NextGen scheduling capability as applied to a set of generic metroplex geometries. A validation study was conducted using an in-house CTAS simulation capability to assess how closely it emulates the real TMA schedules. Results of this validation study are also presented. This research work, which started as a small component within a larger metroplex scheduling evaluation framework, eventually produced some valuable insights related to implications for TMA arrival scheduling as applied to metroplex operations - in a metroplex environment, TMA's delay rippling effect tends to starve the metroplex runways if the arrival flows are not segregated at the TRACON boundary (i.e., if they have to use commonly-shared arrival-fixes). Also, relaxing (i.e., increasing) TMA's terminal delay absorption limit leads to lesser runway starvation, but at the same time it allows for higher terminal delays. More research is needed to find the "sweet-spot" AMDT value which minimizes the runway starvation without increasing the TRACON delays beyond manageable levels. Further research in this direction is expected to provide useful information for supporting future NextGen metroplex arrival scheduling algorithm and Area Navigation (RNAV)/Required Navigation Performance (RNP) terminal route design and development.

A new method for measuring energy intensity during commercial flight missions

Abstract: Today, air traffic contributes with about 2% of the global anthropogenic CO2 generation and constitutes one of the fastest growing transport sectors. With an increase in air transport of about5 % annually since the introduction of civil jet air transport in the early 1950ies, the aviation sector threatens to become a substantial and ever increasing contributor to Greenhouse Gas (GHG) emissions. The very stringent environmental goals introduced by ACARE in their vision for the year 2020 and accepted by, for instance, the European Commission in their “Clean Sky” project for Europe and the Air Traffic Management (ATM) modernization program SESAR of Europe strives for further improvements in energy efficiency. The SESAR activities are closely linked with introduction of new concept of operations. In parallel, airlines are actively working with fuel saving initiatives throughout the world, to minimize its environmental impact. At present there are no standardized tools for measuring and validation of improved energy efficiency and the generation of GHG (in particularly CO2). This is highlighted by the ICAO and seen as a highly prioritized objective. From 2012, the aviation industry is part of the Emission Trading Scheme (ETS) in Europe, where the annual emission of the airline is monitored. However, the monitoring of emissions required by the European ETS is on such a high level that it is not useful in the context of analyzing and validating specific segments of a flight mission or efficiency of different specific flight procedures. The challenge is to validate the increased efficiency associated with different improvements regarding modernization of the aviation industry. This study proposes a new method how to measure energy intensity during the latter part of flight missions, including the last cruise segment through the descent and approach until landing. A traditional concept of operation will be compared with new navigation technologies, for example, utilizing the latest satellite navigation concept by the usage of “curved approaches”, based on Required Navigation Performance Authorization Required (RNP AR) technology.

State of the art in airport navigation

Abstract: The general increase in air traffic and the complexity of modern airport layouts have conducted to think about new technologies to assist pilots during maneuvers on airport surface. Some airport navigation applications have been developed in recent years. The current technologies plot the estimated aircraft position on the airport map. In good visibility condition, this information helps the pilot to navigate on the airport. These applications contribute to the reduction of the taxiing time and runway incursions. Nevertheless, this information is not sufficient to navigate in low visibility condition. This paper introduces the state of the art in airport navigation, with the current functions available to assist pilots, and also the additional applications envisaged to improve the airport navigation in low visibility condition. Current constraints and limitations of airport navigation development are highlighted.

Relative Position Indicator for merging mixed RNAV and vectored arrival traffic

Abstract: The adoption of arrival Area Navigation (RNAV) procedures has been slow partly due to the challenge to controllers of merging RNAV and traditionally vectored arrivals to the same runway without either providing additional spacing or vectoring the arrivals off the RNAV procedure, reducing the benefits of the RNAV procedure. This paper studies two Relative Position Indicator (RPI) concepts, one distance-based and the other trajectory-based, for managing mixed RNAV and vectored arrival traffic, as an way to enable increased adoption of RNAV arrival procedures. The paper presents an analysis of the efficiency of the RPI concepts under a variety of traffic and airspace geometry situations, measured in terms of the percentage of flights that would require vectoring to maintain separation at points where arrival routes merge.

Towards higher levels of automation in taxi guidance: Using GBAS Terminal Area Path (TAP) messages for transmitting taxi routes

Abstract: According to Sheridan and Verplank's classification of levels of automation, taxiing on an airport still has a very low automation level. Key element for increased automation in taxi guidance is a precise and reliable navigation capability. As a Ground Based Augmentation System (GBAS) can fulfill the stringent requirements for a precision approach, it can play an important role in providing the required navigation performance during taxiing as well. This paper will explain the use of GBAS for taxi guidance. It presents, how the required navigation performance for automatic taxiing can be provided using GBAS. Besides the highly precision position service provided via Differential GPS, the Terminal Area Path (TAP) messages will be used to provide the aircraft with accurate and reliable information about the taxi route. Taxi trials with DLR's A320 research aircraft ATRA (Advanced Technology Research Aircraft) and the GBAS ground station at airport Braunschweig-Wolfsburg (EDVE) showed that over the whole maneuvering area the received VHF signal level was adequate for transmitting such a “Ground-TAP”. These tests were performed with an antenna on the aircraft located at a height of 8ft, which is lower than the actual required coverage minimum of 12ft defined in ICAO Annex 10. Together with a redefined voice communication structure and a list of predefined routes the use of GBAS for taxi routing functionalities of an Advanced Surface Movement Guidance & Control System (A-SMGCS) is feasible. Due to the independency from an on-board database the combination of such a message broadcast and the GNSS based positioning can be the key enabler for a future auto taxiing functionality.

Airport Surface Movement – Critical Analysis of Navigation System Performance Requirements

Abstract: The CNS/ATM concept envisages reliance on global satellite navigation systems to underpin future air traffic management that is able to cope with the ever-increasing demand for air travel without jeopardising safety and the environment. In order to benefit from GNSS, it is crucial that the navigation performance required of air navigation systems is derived and agreed, based on sound principles. Significant work has been undertaken to date and agreement reached on the navigation requirements for the phases of flight up to Category I (CAT-I) precision approach, and proposals are under discussion for CAT-III precision approach. This paper completes a typical flight profile by addressing airport surface movement, and proposing the requirements based on operational requirements for each airport category, to support operations in zero visibility conditions. The benefits of the approach taken in the derivation of the requirements are discussed relative to the existing navigation requirements.

A separation standard for departures transitioning from terminal to en route control

Abstract: The advent of radar surveillance over half a century ago enabled numerous Air Traffic Control (ATC) standards that continue to be in use today to safely separate aircraft. In the case of departure operations, the discrete increase of spacing requirements that applies when transitioning from terminal to en route control hampers Next Generation Air Transportation System (NextGen) goals of improving operational efficiencies. This paper proposes the concept of the Established-on-Departure Operation, or EDO, standard that capitalizes on improved navigational precision of Performance Based Navigation (PBN) operations. The concept incorporates current diverging procedures permitted in the terminal area as well as the concept of reduced divergence. The paper describes the requirements for its application and presents the analysis carried out to extend the applicability of a previously proposed standard for reduced-divergence operations. For Area Navigation (RNAV) Standard Instrument Departure (SID) operations, the analysis conservatively quantified a reduced divergence angle of 9 degrees, a 40-percent reduction in angular divergence when compared to today's 15-degree requirement. In order to illustrate implementation examples and estimate potential benefits, the concepts were applied to the RNAV SID structure at The Hartsfield-Jackson Atlanta International Airport (ATL). For ATL alone, the estimates show a potential annual benefit of approximately $1.6 million per year. The standard concepts offer a suite of additional procedure design options not currently available to better accommodate airspace constraints and to increase the efficiency of departure operations transitioning from terminal to en route control.

Novel Integrity Concept for CAT III Precision Approaches and Taxiing: Extended GBAS (E-GBAS)

Abstract: Future air navigation envisages increased use of Global Navigation Satellite Systems (GNSS) together with advanced communications and surveillance technologies to facilitate the required increase in capacity, efficiency and safety without adversely impacting the environment. The full benefit of GNSS is expected from its ability to support en-route to en-route or gate-to-gate air navigation. This presents challenges particularly for the phases of flight with stringent required navigation performance. Significant work has so far been devoted to the phases of flight up to CAT I. However, more work is required for CAT III precision landing (with an accuracy requirement at the metre level) and taxiing (with an accuracy requirement at sub-metre level) and both with very high integrity and continuity requirements. The main limitation in using GBAS for CAT III landings is the potential decorrelation of the measurement errors between the GBAS ground station (GGS) and the user. The threats in this respect are the atmospheric anomalies. Periods of strong solar activity can cause large local spatial and temporal gradients in the delays induced on the GNSS signals by the ionosphere. The local nature of the effects results in significant decorrelation between GGS measurements and the user. Therefore, a reliable ground based ionospheric anomaly monitoring scheme is required to guarantee integrity.This paper critically reviews state-of-the-art monitors, identifies their limitations and addresses them by proposing a high-performance monitoring scheme for the ionosphere. Preliminary analyses suggest that the proposed scheme has the potential to enable GNSS to meet the navigation requirements for CAT III and taxiing.

Navigation system for an aircraft and method of operating such a navigation system

Abstract: The invention relates to an onboard navigation system for an aircraft ( 10 ), particularly a navigation system for a helicopter and to a method of operating such a navigation system allowing improvement of safety of an aircraft and its crew.

Use of magnetic variation and station declination for heading (VX) and course (CX) leg types

Abstract: Leg types, also known as path terminators, are used in aircraft navigation to define paths as routes for RNAV equipped aircraft. Many leg types are specifically defined to cause the Area Navigation (RNAV) system to emulate the actions that an aircrew would take when flying the route manually based on the text and other depictions on the chart. Some emulate magnetic headings or courses, which, for various reasons, can lead to differences between what the procedure designer intended and what the RNAV system displays or flies. Two in particular are in common use individually and in combination, and this paper will explore the potential for unexpected differences in the resulting paths. These two are the heading type (Vx) which may be used where the procedure or airspace designer calls for a heading to some type of termination, and the Course type (Cx) which may be used where designers wish to fix the aircraft path over the ground using a course defined by a navigational aid (NAVAID). Issues arise because of the need to implement magnetic courses and headings in an RNAV system that navigates in a true north reference frame. Given that the Earth's magnetic field orientation varies with location on the Earth (hence true north and magnetic north change relative to each other), changes with time, and that NAVAIDS and runways are marked/oriented in the magnetic reference frame of the time they are surveyed, care must be taken to make the RNAV system emulate the procedure intent; this paper will describe and summarize those cautions and issues.

4D Dynamic Required Navigation Performance Final Report

Abstract: New advanced four dimensional trajectory (4DT) procedures under consideration for the Next Generation Air Transportation System (NextGen) require an aircraft to precisely navigate relative to a moving reference such as another aircraft. Examples are Self-Separation for enroute operations and Interval Management for in-trail and merging operations. The current construct of Required Navigation Performance (RNP), defined for fixed-reference-frame navigation, is not sufficiently specified to be applicable to defining performance levels of such air-to-air procedures. An extension of RNP to air-to-air navigation would enable these advanced procedures to be implemented with a specified level of performance. The objective of this research effort was to propose new 4D Dynamic RNP constructs that account for the dynamic spatial and temporal nature of Interval Management and Self-Separation, develop mathematical models of the Dynamic RNP constructs, "Required Self-Separation Performance" and "Required Interval Management Performance," and to analyze the performance characteristics of these air-to-air procedures using the newly developed models. This final report summarizes the activities led by Raytheon, in collaboration with GE Aviation and SAIC, and presents the results from this research effort to expand the RNP concept to a dynamic 4D frame of reference.

Speed control on RNAV OPD for near-term ATM TRACON operations

Abstract: The use of RNAV procedures in the terminal area coupled with optimal profile descents (OPD) is showing promise as a viable near-term step towards full blown NextGen trajectory based operations. A strong point of RNAV OPD operations in the TRACON is that they can be performed with existing avionics capabilities as most modern transport aircraft have Flight Management Systems (FMS) capable of RNAV and Vertical Navigation (VNAV). In fact, such an operation is currently being considered by the FAA as a candidate for extension of 3D Paths in Arrival Management (3D PAM) operations through the TRACON. The objective is to determine how controllers and pilots can support this RNAV-based operation with little or no reversion to manual vectoring, even in complex high-density airspace. This paper examines the use of speed intervention during an RNAV procedure as a means of ensuring safe spacing through terminal area merge points, while executing OPD procedures.

Traffic Flow Management exploiting increased navigation performance

Abstract: 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.