Effect of operating variables on pollutant emissions from aircraft turbine engine combustors
Operational methods for control of air pollution emissions from aircraft turbine engine combustor
Grobman, J.↗
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Small Aircraft Transportation System, Higher Volume Operations Concept: Off-Nominal Operations
This document expands the Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept to include off-nominal conditions. The general philosophy underlying the HVO concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). During periods of poor weather, a block of airspace would be established around designated non-towered, non-radar airports. Aircraft flying enroute to a SATS airport would be on a standard instrument flight rules flight clearance with Air Traffic Control providing separation services. Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Previous work developed the procedures for normal HVO operations. This document provides details for off-nominal and emergency procedures for situations that could be expected to occur in a future SCA.
Abbott, Terence S.↗
Wind Information Uplink to Aircraft Performing Interval Management Operations
The accuracy of the wind information used to generate trajectories for aircraft performing Interval Management (IM) operations is critical to the success of an IM operation. There are two main forms of uncertainty in the wind information used by the Flight Deck Interval Management (FIM) equipment. The first is the accuracy of the forecast modeling done by the weather provider. The second is that only a small subset of the forecast data can be uplinked to the aircraft for use by the FIM equipment, resulting in loss of additional information. This study focuses on what subset of forecast data, such as the number and location of the points where the wind is sampled should be made available to uplink to the aircraft.
Ahmad, Nashat↗
Airborne Science Program: Observing Platforms for Earth Science Investigations
This slide presentation reviews the Airborne Science Program and the platforms used for conducting investigations for the Earth System Science. Included is a chart that shows some of the aircraft and the operational altitude and the endurance of the aircraft, views of the Dryden Aircraft Operation Facility, and some of the current aircraft that the facility operates, and the varieties of missions that are flown and the type of instrumentation. Also included is a chart showing the attributes of the various aircraft (i.e., duration, weight for a payload, maximum altitude, airspeed and range) for comparison
Mace, Thomas H.↗
Runway drainage characteristics related to tire friction performance
The capability of a runway pavement to rapidly drain water buildup during periods of precipitation is crucial to minimize tire hydroplaning potential and maintain adequate aircraft ground operational safety. Test results from instrumented aircraft, ground friction measuring vehicles, and NASA Langley's Aircraft Landing Dynamics Facility (ALDF) track have been summarized to indicate the adverse effects of pavement wetness conditions on tire friction performance. Water drainage measurements under a range of rainfall rates have been evaluated for several different runway surface treatments including the transversely grooved and longitudinally grinded concrete surfaces at the Space Shuttle Landing Facility (SLF) runway at NASA Kennedy Space Center in Florida. The major parameters influencing drainage rates and extent of flooding/drying conditions are identified. Existing drainage test data are compared to a previously derived empirical relationship and the need for some modification is indicated. The scope of future NASA Langley research directed toward improving empirical relationships to properly define runway drainage capability and consequently, enhance aircraft ground operational safety, is given.
Yager, Thomas J.↗
Aircraft maneuver envelope warning system
A maneuver envelope warning system for an aircraft having operating limits, operating condition sensors and an indicator driver. The indicator driver has a plurality of visual indicators. The indicator driver determines a relationship between sensed operating conditions and the operating limits; such as, a ratio therebetween. The indicator driver illuminates a number of the indicators in proportion to the determined relationship. The position of the indicators illuminated represents to a pilot in an easily ascertainable manner whether the operational conditions are approaching operational limits of the aircraft, and the degree to which operational conditions lie within or exceed operational limits.
Bivens, Courtland C.↗
Stator Loading Measurements Behind a Fan With Trailing Edge Blowing
The problem of aircraft noise pollution around airports has become increasingly important as those areas have become more densely populated. Currently, the removal of older noisier aircraft from operation is reducing noise levels around airports; however, with air traffic projected to increase by about 5% over the next decade the number of commercial aircraft operating in the world is expected to be about 17,700 by the year 2007. To keep noise levels around airports from increasing as a result of traffic increases, it is important to investigate new methods of noise reduction. The objective of this work is to provide a better understanding of the effects that trailing edge blowing has on stator unsteady loading. This is done by presenting flowfield and stator loading data from experiments conducted with and without trailing edge blowing.
Waitz, Ian A.↗
Small Aircraft Transportation System, Higher Volume Operations Concept: Normal Operations
This document defines the Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) concept for normal conditions. In this concept, a block of airspace would be established around designated non-towered, non-radar airports during periods of poor weather. Within this new airspace, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Using onboard equipment and procedures, they would then approach and land at the airport. Departures would be handled in a similar fashion. The details for this operational concept are provided in this document.
Abbott, Terence S.↗
Vortex-Free Flight Corridors for Aircraft Executing Compressed Landing Operations
A factor that limits airport arrival and departure rates is the need to wait between operations for the wake vortices of preceding aircraft to decay to a safe level. As airport traffic demand increases, creative methods will be needed to overcome the limitations caused by the hazard posed by vortex wakes so that airport capacities can be increased. The problem addressed here is the design of vortex-free trajectories for aircraft as they fly from their cruise altitudes down to their final approach paths and to a landing. The guidelines presented recommend that the flight path of each aircraft in a group executing nearly-simultaneous landings be spaced far enough apart laterally along organized flight paths so that the vortex wakes of preceding aircraft will not intrude into the airspace to be used by following aircraft. An example is presented as to how a combination of straight lines and circular arcs is able to provide each aircraft in a group with a vortex-free trajectory so that all are able to safely form the pattern needed for nearly simultaneous landings on a set of closely-spaced parallel runways. Although the guidelines me described for aircraft on approach, they are also applicable to departure, and to en route operations.
Rossow, Vernon J.↗
Operational Experiences of General Aviation Aircraft
An investigation is currently under way to determine the operational practices and load experiences of general aviation aircraft performing five basic types of operations: twin-engine executive, single-engine executive, personal, instructional, and commercial survey. Limited data obtained to date from aircraft engaged in these operations indicate that aircraft are generally being operated within the limits to which they were designed.
Jewel, Joseph W., Jr.↗
Analysis of Navy radome failure problems
A survey of radome failure problems in military aircraft under actual operating conditions was conducted. The aircraft were operating from aircraft carriers in the Pacific Ocean. Critical problem areas were identified and a plan was developed for failure prevention. The development and application of repair kits for correcting the erosion damage are reported. It is stated that the rain erosion damage survey established a strong justification for qualification testing of all materials and designs which may have questionable life expectancy on the aircraft.
Tatnall, G. J.↗
Small Aircraft Transportation System Higher Volume Operations Concept
This document defines the Small Aircraft Transportation System (SATS) Higher Volume Operations concept. The general philosophy underlying this concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. This document also provides details for a number of off-nominal and emergency procedures which address situations that could be expected to occur in a future SCA. The details for this operational concept along with a description of candidate aircraft systems to support this concept are provided.
Abbott, Terence S.↗
Weather Requirements and Procedures for Step 1: High Altitude Long Endurance (HALE) Unmanned Aircraft System (UAS) Flight Operations in the National Air Space (NAS)
This cover sheet is for version 2 of the weather requirements document along with Appendix A. The purpose of the requirements document was to identify and to list the weather functional requirements needed to achieve the Access 5 vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the National Airspace System (NAS) for Step 1." A discussion of the Federal Aviation Administration (FAA) references and related policies, procedures, and standards is provided as basis for the recommendations supported within this document. Additional procedures and reference documentation related to weather functional requirements is also provided for background. The functional requirements and related information are to be proposed to the FAA and various standards organizations for consideration and approval. The appendix was designed to show that sources of flight weather information are readily available to UAS pilots conducting missions in the NAS. All weather information for this presentation was obtained from the public internet.
Source record↗
Alert Timing Assessment for Unmanned Aircraft System Terminal Area Operation
Explore the source record for details and available documents.
Unmanned Aircraft Systems↗
A Simulation Architecture for Air Traffic Over Urban Environments Supporting Autonomy Research in Advanced Air Mobility
As part of its research, NASA investigates concepts, aircraft, and operations related to Advanced Air Mobility (AAM). One of the most challenging scenarios for AAM will be enabling safe routine access near densely populated urban centers. AAM flight operations over a regional area require a moderately high-fidelity simulation capability to develop and evaluate autonomy technologies in the urban environment. This paper aims to describe a system to simulate flight operations around regions such as the San Francisco-Oakland Bay area at a moderately-high scale (tens to hundreds of flights) that incorporates detailed vehicle models and control necessary to support research in airborne autonomy. The flight vehicle utilizes NASA AAM concept vehicle dynamics integrated with a custom flight management system and flight control system to simulate all flight phases accurately. The simulation incorporates a detailed simulated urban environment and includes glass cockpit displays to monitor aircraft operations. Simulation models integrate to simulate air and ground-based sensors, such as Radar and LiDAR. As a commercially available rendering engine, X-Plane 11 is used as the renderer to simulate vision-based sensors (such as onboard and ground-based cameras) with a detailed graphical model of a city at different times of the day and weather conditions. This paper presents the simulation and software architecture used for simulating AAM traffic over this urban region. This system enables the evaluation of NASA research concepts in autonomy for urban AAM operations on the path toward flight test evaluation.
distributed sensing↗
A Simulation Architecture for Air Traffic Over Urban Environments Supporting Autonomy Research in Advanced Air Mobility
As part of its research, NASA investigates concepts, aircraft, and operations related to Advanced Air Mobility (AAM). One of the most challenging scenarios for AAM will be enabling safe routine access near densely populated urban centers. AAM flight operations over a regional area require a moderately high-fidelity simulation capability to develop and evaluate autonomy technologies in the urban environment. This paper aims to describe a system to simulate flight operations around regions such as the San Francisco-Oakland Bay area at a moderately-high scale (tens to hundreds of flights) that incorporates detailed vehicle models and control necessary to support research in airborne autonomy. The flight vehicle utilizes NASA AAM concept vehicle dynamics integrated with a custom flight management system and flight control system to simulate all flight phases accurately. The simulation incorporates a detailed simulated urban environment and includes glass cockpit displays to monitor aircraft operations. Simulation models integrate to simulate air and ground-based sensors, such as Radar and LiDAR. As a commercially available rendering engine, X-Plane 11 is used as the renderer to simulate vision-based sensors (such as onboard and ground-based cameras) with a detailed graphical model of a city at different times of the day and weather conditions. This paper presents the simulation and software architecture used for simulating AAM traffic over this urban region. This system enables the evaluation of NASA research concepts in autonomy for urban AAM operations on the path toward flight test evaluation.
Distributed sensing↗
Alert Timing Assessment for Unmanned Aircraft System Terminal Area Operations
A Detect and Avoid (DAA) system is an essential enabler for integrating Unmanned Aircraft Systems (UAS) into the U.S. National Airspace System. A DAA system uses a suite of sensors, trackers and alerting and guidance algorithms to assist a remote pilot in maintaining separation from airborne traffic. The initial minimum performance standards focused on en route operations; in order to facilitate operations in and around the airport environment, this paper presents the derivation of the early alert threshold for UAS terminal operations.
Unmanned Aircraft Systems↗
Next Generation Aircraft Design Considering Airline Operations and Economics
Traditional approaches to design and optimization of a new system often use a system-centric objective and do not take into consideration how the operator will use this new system alongside other existing systems. When the new system design is incorporated into the broader group of systems, the performance of the operator-level objective can be sub-optimal due to the unmodeled interaction between the new system and the other systems. Among the few available references that describe attempts to address this disconnect, most follow an MDO (Multidisciplinary Design Optimization)-motivated sequential decomposition approach of first designing a very good system and then providing this system to the operator who, decides the best way to use this new system along with the existing systems. This paper addresses this issue by including aircraft design, airline operations, and revenue management "subspaces"; and presents an approach that could simultaneously solve these subspaces posed as a monolithic optimization problem rather than the traditional approach described above. The monolithic approach makes the problem an expensive Mixed Integer Non-Linear Programming problem, which are extremely difficult to solve. To address the problem, we use a recently developed optimization framework that simultaneously solves the subspaces to capture the "synergy" in the problem that the previous decomposition approaches did not exploit, addresses mixed-integer/discrete type design variables in an efficient manner, and accounts for computationally expensive analysis tools. This approach solves an 11-route airline network problem consisting of 94 decision variables including 33 integer and 61 continuous type variables. Simultaneously solving the subspaces leads to significant improvement in the fleet-level objective of the airline when compared to the previously developed sequential subspace decomposition approach.
Roy, Satadru↗