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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 775 records · Page 43

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NASA NTRS1999

A Simulation Study of Instrument Meteorological Condition Approaches to Dual Parallel Runways Spaced 3400 and 2500 Feet Apart Using Flight-Deck-Centered Technology

A number of our nations airports depend on closely spaced parallel runway operations to handle their normal traffic throughput when weather conditions are favorable. For safety these operations are curtailed in Instrument Meteorological Conditions (IMC) when the ceiling or visibility deteriorates and operations in many cases are limited to the equivalent of a single runway. Where parallel runway spacing is less than 2500 feet, capacity loss in IMC is on the order of 50 percent for these runways. Clearly, these capacity losses result in landing delays, inconveniences to the public, increased operational cost to the airlines, and general interruption of commerce. This document presents a description and the results of a fixed-base simulation study to evaluate an initial concept that includes a set of procedures for conducting safe flight in closely spaced parallel runway operations in IMC. Consideration of flight-deck information technology and displays to support the procedures is also included in the discussions. The procedures and supporting technology rely heavily on airborne capabilities operating in conjunction with the air traffic control system.

Waller, Marvin C.↗

NASA NTRSDate not supplied

Automated Airspace Management: Concept, Development, and Testing

For many decades, researchers at NASA Ames Research Center have worked to make the air-transportation system more efficient, predictable, and effective. Since about 2005 one important aspect of this research has been the development of an autonomous system for air-traffic control. This system, known as the Autoresolver, is designed to perform most of the roles that air-traffic controllers perform including ensuring separation between aircraft, creating routes around weather and other avoidance volumes, and sequencing and scheduling aircraft across points in space. The recent, rapid expansion of new aircraft operations and types, including urban air mobility aircraft and small unmanned aerial systems, have only increased the need for highly automated systems to control the predicted traffic demand. This talk will focus on the development of the Autoresolver - from concept to testing. It will also discuss the National Airspace (NAS) Digital Twin simulation platform, created to facilitate rapid testing and improvement of the algorithm and with the hope of proving the automation in a high-fidelity environment. An open question that will be discussed is how to ensure that the system-level emergent behavior of independently developed autonomous algorithms is what is desired.

autonomy↗

NASA NTRS1985

A preliminary study of the basic display/guidance requirements for flying near optimal trajectories

NASA has responded to the increased emphases on cost-efficient operation of today's airline fleet with an ongoing research program to investigate the requirements and benefits of using new airborne guidance and pilot procedures designed to yield cost-optimal flight profiles that are compatible with advanced air traffic control system concepts. A trajectory optimization algorithm has been incorporated into one of NASA Langley's fixed-based simulators to investigate the pilot/cockpit interface requirements. The trajectories that are generated by this algorithm differ from conventional profiles in that they are constantly varying in both flight path angle and airspeed. Considering the dynamic nature of these profiles, conventional guidance may be insufficient for practical use. This paper summarizes the results of an initial set of piloted simulation tests to investigate the basic guidance requirements for flying the near-optimal trajectories.

Vicroy, D. D.↗

NASA NTRS1986

Flight management concepts compatible with air traffic control

With the advent of airline deregulation and increased competition, the need for cost efficient airline operations is critical. This paper summarizes past research efforts and planned research thrusts toward the development of compatible flight management and air traffic control systems that promise increased operational effectiveness and efficiency. Potential capacity improvements resulting from a time-based ATC simulation (fast-time) are presented. Advanced display concepts with time guidance and velocity vector information to allow the flight crew to play an important role in the future ATC environment are discussed. Results of parametric sensitivity analyses are also presented that quantify the fuel/cost penalties for idle-thrust mismodeling and wind-modeling errors.

Morello, S. A.↗

NASA NTRS1993

Data communication network at the ASRM facility

The main objective of the report is to present the overall communication network structure for the Advanced Solid Rocket Motor (ASRM) facility being built at Yellow Creek near Iuka, Mississippi. This report is compiled using information received from NASA/MSFC, LMSC, AAD, and RUST Inc. As per the information gathered, the overall network structure will have one logical FDDI ring acting as a backbone for the whole complex. The buildings will be grouped into two categories viz. manufacturing critical and manufacturing non-critical. The manufacturing critical buildings will be connected via FDDI to the Operational Information System (OIS) in the main computing center in B 1000. The manufacturing non-critical buildings will be connected by 10BASE-FL to the Business Information System (BIS) in the main computing center. The workcells will be connected to the Area Supervisory Computers (ASCs) through the nearest manufacturing critical hub and one of the OIS hubs. The network structure described in this report will be the basis for simulations to be carried out next year. The Comdisco's Block Oriented Network Simulator (BONeS) will be used for the network simulation. The main aim of the simulations will be to evaluate the loading of the OIS, the BIS, the ASCs, and the network links by the traffic generated by the workstations and workcells throughout the site.

Moorhead, Robert J., II↗

NASA NTRS1994

Spatial awareness comparisons between large-screen, integrated pictorial displays and conventional EFIS displays during simulated landing approaches

An extensive simulation study was performed to determine and compare the spatial awareness of commercial airline pilots on simulated landing approaches using conventional flight displays with their awareness using advanced pictorial 'pathway in the sky' displays. Sixteen commercial airline pilots repeatedly made simulated complex microwave landing system approaches to closely spaced parallel runways with an extremely short final segment. Scenarios involving conflicting traffic situation assessments and recoveries from flight path offset conditions were used to assess spatial awareness (own ship position relative the the desired flight route, the runway, and other traffic) with the various display formats. The situation assessment tools are presented, as well as the experimental designs and the results. The results demonstrate that the integrated pictorial displays substantially increase spatial awareness over conventional electronic flight information systems display formats.

Parrish, Russell V.↗

NASA NTRS1995

A Collection of Technical Papers

Papers presented at the 6th Space Logistics Symposium covered such areas as: The International Space Station; The Hubble Space Telescope; Launch site computer simulation; Integrated logistics support; The Baikonur Cosmodrome; Probabalistic tools for high confidence repair; A simple space station rescue vehicle; Integrated Traffic Model for the International Space Station; Packaging the maintenance shop; Leading edge software support; Storage information management system; Consolidated maintenance inventory logistics planning; Operation concepts for a single stage to orbit vehicle; Mission architecture for human lunar exploration; Logistics of a lunar based solar power satellite scenario; Just in time in space; NASA acquisitions/logistics; Effective transition management; Shuttle logistics; and Revitalized space operations through total quality control management.

Source record↗

NASA NTRS2001

Achieving QoS for TCP Traffic in Satellite Networks with Differentiated Services

Satellite networks play an indispensable role in providing global Internet access and electronic connectivity. To achieve such a global communications, provisioning of quality of service (QoS) within the advanced satellite systems is the main requirement. One of the key mechanisms of implementing the quality of service is traffic management. Traffic management becomes a crucial factor in the case of satellite network because of the limited availability of their resources. Currently, Internet Protocol (IP) only has minimal traffic management capabilities and provides best effort services. In this paper, we presented a broadband satellite network QoS model and simulated performance results. In particular, we discussed the TCP flow aggregates performance for their good behavior in the presence of competing UDP flow aggregates in the same assured forwarding. We identified several factors that affect the performance in the mixed environments and quantified their effects using a full factorial design of experiment methodology.

Durresi, Arjan↗

NASA NTRS2015

Assessing Resilience of Scheduled Performance-Based Navigation Arrival Operations

This paper assesses the resilience of scheduled Performance-Based Navigation (PBN) arrival operations. Resilience is defined as an ability to return to nominal operations following a schedule perturbation. Results from a Human-in-the- Loop (HITL) experiment that included off-nominal events to perturb the schedule are described. The schedule comes from a precision trajectory-based arrival manager. The experiment collected data regarding the response to perturbed schedules in three conditions, where: 1) a disturbance rejection algorithm made schedule adjustments automatically, 2) a Traffic Management Coordinator (TMC) participant made schedule adjustments manually, or 3) no schedule adjustments were made. Analyses showed that the simulation’s scheduled PBN operations have inherent resilience, recovering from more than half of the perturbed schedules even with no schedule adjustments. Resilience to the same off-nominal events improved with schedule adjustments; an increased proportion of perturbed schedules recovered within the length of operation run, and the average duration of the schedule’s perturbed state decreased. Compared to the manual schedule adjustments condition, a greater number of schedule adjustments occurred for the same off-nominal events in the automated condition. However, perturbed schedules were recovered more frequently and perturbations were less severe in the automated condition. Subjective and objective workload in the manual and the automated schedule adjustment conditions were similar to the no schedule adjustment condition.

Resilience↗

NASA NTRSDate not supplied

Upper E Traffic Management

This is a slide set as part of a meeting series with members of a working group aimed at the development of a concept that addresses needs and gaps in the management of high altitude airspace operations. This concept leverages elements developed through the UAS Traffic Management project with respect to a cooperative, service-based approach that provides services and capabilities in areas (e.g., Upper E airspace) that currently receive no or limited service from Air Traffic Control. This concept is meant to provide a safe, fair, and scalable approach to management of Upper E operations that reduces the burden on ATC while providing the flexibility and access desired by current and new users of the airspace. This set of slides includes an overview of discussions and industry news covering the time since the previous group meeting, a recap of the group's history and road ahead, a discussion of industry's initial position on, 'Industry principles for ETM rules of the road: Conflict identification and resolution,' and a simulation roadmap for planned work ahead.

Upper E↗

NASA NTRS1988

Laminar flow control leading edge systems in simulated airline service

The feasibility of two candidate leading-edge flow laminarization systems applicable to airline service was tested using representative airline operational conditions with respect to air traffic, weather, and airport insect infestation. One of the systems involved a perforated Ti alloy suction surface with about 1 million 0.0025-in. diameter holes drilled by electron beam, as well as a Krueger-type flap that offered protective shielding against insect impingement; the other supplied surface suction through a slotted Ti alloy skin with 27 spanwise slots on the upper and lower surface.

Wagner, R. D.↗

NASA NTRS2011

Identifying Functional Requirements for Flexible Airspace Management Concept Using Human-In-The-Loop Simulations

Flexible Airspace Management (FAM) is a mid- term Next Generation Air Transportation System (NextGen) concept that allows dynamic changes to airspace configurations to meet the changes in the traffic demand. A series of human-in-the-loop (HITL) studies have identified procedures and decision support requirements needed to implement FAM. This paper outlines a suggested FAM procedure and associated decision support functionality based on these HITL studies. A description of both the tools used to support the HITLs and the planned NextGen technologies available in the mid-term are presented and compared. The mid-term implementation of several NextGen capabilities, specifically, upgrades to the Traffic Management Unit (TMU), the initial release of an en route automation system, the deployment of a digital data communication system, a more flexible voice communications network, and the introduction of a tool envisioned to manage and coordinate networked ground systems can support the implementation of the FAM concept. Because of the variability in the overall deployment schedule of the mid-term NextGen capabilities, the dependency of the individual NextGen capabilities are examined to determine their impact on a mid-term implementation of FAM. A cursory review of the different technologies suggests that new functionality slated for the new en route automation system is a critical enabling technology for FAM, as well as the functionality to manage and coordinate networked ground systems. Upgrades to the TMU are less critical but important nonetheless for FAM to be fully realized. Flexible voice communications network and digital data communication system could allow more flexible FAM operations but they are not as essential.

dynamic airspace configuration↗

NASA NTRS1992

Simulation Of Static And Moving Acoustical Sources

Sounds in headphones changed according to movements of listener's head. Signal processor generates three-dimensional sound cues for headphones. Provides up to four independent acoustical sources simultaneously and simulates movements of each source in real time. Used to enhance presentations of data in cockpits of airplanes, in air-traffic-control towers, for training people whose hearing is impaired, for monitoring telerobots in hazardous situations, and for visualizing multidimensional scientific data, among many possible applications.

Wenzel, Elizabeth M.↗

NASA NTRS1997

Decentralized and Tactical Air Traffic Flow Management

This project dealt with the following topics: 1. Review and description of the existing air traffic flow management system (ATFM) and identification of aspects with potential for improvement. 2. Identification and review of existing models and simulations dealing with all system segments (enroute, terminal area, ground) 3. Formulation of concepts for overall decentralization of the ATFM system, ranging from moderate decentralization to full decentralization 4. Specification of the modifications to the ATFM system required to accommodate each of the alternative concepts. 5. Identification of issues that need to be addressed with regard to: determination of the way the ATFM system would be operating; types of flow management strategies that would be used; and estimation of the effectiveness of ATFM with regard to reducing delay and re-routing costs. 6. Concept evaluation through identification of criteria and methodologies for accommodating the interests of stakeholders and of approaches to optimization of operational procedures for all segments of the ATFM system.

Odoni, Amedeo R.↗

NASA NTRS1997

Decentralized and Tactical Air Traffic Flow Management

Amedeo R. Odoni↗

NASA NTRS1999

A System for Integrated Reliability and Safety Analyses

We present an integrated reliability and aviation safety analysis tool. The reliability models for selected infrastructure components of the air traffic control system are described. The results of this model are used to evaluate the likelihood of seeing outcomes predicted by simulations with failures injected. We discuss the design of the simulation model, and the user interface to the integrated toolset.

Kostiuk, Peter↗

NASA NTRS2003

Airborne Conflict Management within Confined Airspace in a Piloted Simulation of DAG-TM Autonomous Aircraft Operations

A human-in-the-loop experiment was performed at the NASA Langley Research Center to study the feasibility of Distributed Air/Ground Traffic Management (DAG-TM) autonomous aircraft operations in highly constrained airspace. The airspace was constrained by a pair of special use airspace (SUA) regions on either side of the pilot s planned route. The available airspace was further varied by changing the separation standard for lateral separation between 3 nm and 5 nm. The pilot had to maneuver through the corridor between the SUA s, avoid other traffic and meet flow management constraints. Traffic flow management (TFM) constraints were imposed as a required time of arrival and crossing altitude at an en route fix. This is a follow-up study to work presented at the 4th USA/Europe Air Traffic Management R&D Seminar in December 2001. Nearly all of the pilots were able to meet their TFM constraints while maintaining adequate separation from other traffic. In only 3 out of 59 runs were the pilots unable to meet their required time of arrival. Two loss of separation cases are studied and it is found that the pilots need conflict prevention information presented in a clearer manner. No degradation of performance or safety was seen between the wide and narrow corridors. Although this was not a thorough study of the consequences of reducing the en route lateral separation, nothing was found that would refute the feasibility of reducing the separation requirement from 5 nm to 3 nm. The creation of additional, second-generation conflicts is also investigated. Two resolution methods were offered to the pilots: strategic and tactical. The strategic method is a closed-loop alteration to the Flight Management System (FMS) active route that considers other traffic as well as TFM constraints. The tactical resolutions are short-term resolutions that leave avoiding other traffic conflicts and meeting the TFM constraints to the pilot. Those that made use of the strategic tools avoided additional conflicts, whereas, those making tactical maneuvers often caused additional conflicts. Many of these second-generation conflicts could be avoided by improved conflict prevention tools that clearly present to the pilot which maneuver choices will result in a conflict-free path. These results, together with previously reported studies, continue to support the feasibility of autonomous aircraft operations.

Barmore, Bryan↗

NASA NTRS2006

Journal of Air Transportation, Volume 11, No. 2

The following topics were covered: How Do Airlines Perceive That Strategic Alliances Affect Their Individual Branding?; Airline Choice for Domestic Flights in Sao Paulo Metropolitan Area: An Application of the Conditional Logit Model; Consequences of Feeder Delays for the Success of A380 Operations; Inside the Mechanics of Network Development: How Competition and Strategy Reorganize European Air Traffic; The Opportunities and Threats of Turning Airports into Hubs; Another Approach to Enhance Airline Safety: Using System Safety Tools; A Simulation Based Approach for Contingency Planning for Aircraft Turnaround Activities in Airline Hubs; and The Council on Aviation Accreditation: Part One- Historical Foundation.

Bowen, Brent↗