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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Equivalent damage: A critical assessment

The overall goal of achieving improved life cycle management of aircraft engine, gas turbine components is a major industry thrust. Low cycle fatigue (LCF) crack initiation prediction, an important element of life cycle management as traditionally applied, may be overly conservative in estimating total cyclic life capability. Consequently, there is increasing pressure to improve predictive methods both for crack initiation and for subsequent crack propagation. The utility of equivalent damage concepts for application to hot section components of aircraft engines was studied. Specifically, the topics examined were mean stress, cumulative damage, and multiaxiality. Other factors inherently linked to this study were the basic formulation of damage parameters at elevated temperatures and the fact that hot section components experience severe temperature fluctuations throughout their service lifetime.

Laflen, J. H.↗
NASA NTRS2016

Kennedy Space Center Five Year Sustainability Plan

The Federal Government is committed to following sustainable principles. At its heart, sustainability integrates environmental, societal and economic solutions for present needs without compromising the ability of future generations to meet their needs. Building upon its pledge towards environmental stewardship, the Administration generated a vision of sustainability spanning ten goals mandated within Executive Order (EO) 13693, Planning for Federal Sustainability in the Next Decade. In November 2015, the National Aeronautics and Space Administration (NASA) responded to this EO by incorporating it into a new release of the NASA Strategic Sustainability Performance Plan (SSPP). The SSPP recognizes the importance of aligning environmental practices in a manner that preserves, enhances and strengthens NASA's ability to perform its mission indefinitely. The Kennedy Space Center (KSC) is following suit with KSC's Sustainability Plan (SP) by promoting, maintaining and pioneering green practices in all aspects of our mission. KSC's SP recognizes that the best sustainable solutions use an interdisciplinary, collaborative approach spanning civil servant and contractor personnel from across the Center. This approach relies on the participation of all employees to develop and implement sustainability endeavors connected with the following ten goals: Reduce greenhouse gas (GHG) emissions. Design, build and maintain sustainable buildings, facilities and infrastructure. Leverage clean and renewable energy. Increase water conservation. Improve fleet and vehicle efficiency and management. Purchase sustainable products and services. Minimize waste and prevent pollution. Implement performance contracts for Federal buildings. Manage electronic equipment and data centers responsibly. Pursue climate change resilience. The KSC SP details the strategies and actions that address the following objectives: Reduce Center costs. center dot Increase energy and water efficiencies. Promote smart buying practices. Increase reuse and recycling while decreasing waste. Benefit the community. Meet or exceed the EO and NASA SSPP sustainability goals.

Sustainability↗
NASA NTRS2020

Area South of K7-516, SWMU 100 Operations, Maintenance, and Monitoring Report Kennedy Space Center, Florida

This Operations, Maintenance, and Monitoring Report documents groundwater interim measure activities from March 30, 2019 through December 31, 2019 at the Area South of K7-516 site located at Kennedy Space Center (KSC), Florida. An air sparge (AS) system consisting of 16 AS wells was installed along the Barge Canal in 2012 to be protective of the Outstanding Florida Waters (OFW). The AS system was expanded in 2015 by installing 40 AS wells to remediate the hot spot (HS) area. Additional expansion activities were performed in 2018 through the installation of eight additional AS wells along the Barge Canal. Currently 24 OFW and 40 HS AS wells are in operation. This report includes performance monitoring events for the OFW and HS areas, along with an annual Interim Groundwater Monitoring (IGWM) event in the Western Area. The 516S site has been designated Solid Waste Management Unit 100 under KSC’s Resource Conservation and Recovery Act Corrective Action program. This document was prepared by Tetra Tech, Inc., for the National Aeronautics and Space Administration under Indefinite Delivery Indefinite Quantity Contract 80KSC019D0011/80KSC019F0068. The OFW and HS AS systems are meeting the performance criteria and IM objectives of preventing contaminant migration and remediating groundwater within the treatment zone. Team consensus was reached to continue operation of the combined OFW and HS AS systems (Meeting Minute 2002-M02, Decisions 2002-D06, D09 and D04). Team consensus was also reached to continue semi-annual OFW performance monitoring and annual monitoring for the IGWM Western Area for the same wells sampled during 2019 events. In the eastern area, MW13, MW14, and MW15 will be reduced from semi-annual to annual frequency. For the HS Area, team consensus was reached to continue the current annual/biennial monitoring program (Meeting Minute 2002-M02, Decisions 2002-D02, D03, D05, D07 and D08).

Patrice L. Lehocky↗
NASA NTRS2020

Costa Rica & Panama Ecological Forecasting II: Identifying Current and Future Areas of Environmental Concern in La Amistad International Park to Inform Resource Management

Seven percent of all scientifically known life forms lie within the 202,230 square miles of Central America, making this area ecologically unique and increasing the need for environmental management. The Mesoamerican Biological Corridor forms a conservation partnership throughout Central America to establish a forested corridor of over 600 protected areas. Although conservation programs exist, deforestation still afflicts the area, putting strain on these diverse ecosystems. La Amistad International Park in southern Costa Rica and northern Panama in particular faces conflicting land use changes. Expanding agricultural development and urbanization, combined with concern over indigenous land rights, have raised questions about the implementation of sustainability goals and communication strategies within the region. To help address these issues, the NASA DEVELOP Costa Rica & Panama Ecological Forecasting II team continued a partnership with the Ministry of Environment and Energy in Costa Rica and the National Environmental Authority in Panama. The team created a Land Use Conflict Identification Strategy (LUCIS) model based on land cover maps for 2019 and 2029 that were created in term I using imagery from Landsat 8 Operational Land Imager (OLI). With partner input, the team applied weights to different objectives and combined suitability maps to identify areas of potential biodiversity conflict. Additionally, the team created a Short-term Forest Change (SFTC) Tool using Terra Moderate Resolution Imaging Spectroradiometer, Landsat 8 OLI, and Sentinel-2 Multispectral Instrument to help the partners identify areas of immediate, major forest changes. The LUCIS model indicated higher agricultural growth when compared to the ecological category.

Ecological Forecasting↗
NASA NTRS2020

Costa Rica & Panama Ecological Forecasting II: Identifying Current and Future Areas of Environmental Concern in La Amistad International Park to Inform Resource Management

Seven percent of all scientifically known life forms lie within the 202,230 square miles of Central America, making this area ecologically unique and increasing the need for environmental management. The Mesoamerican Biological Corridor forms a conservation partnership throughout Central America to establish a forested corridor of over 600 protected areas. Although conservation programs exist, deforestation still afflicts the area, putting strain on these diverse ecosystems. La Amistad International Park in southern Costa Rica and northern Panama in particular faces conflicting land use changes. Expanding agricultural development and urbanization, combined with concern over indigenous land rights, have raised questions about the implementation of sustainability goals and communication strategies within the region. To help address these issues, the NASA DEVELOP Costa Rica & Panama Ecological Forecasting II team continued a partnership with the Ministry of Environment and Energy in Costa Rica and the National Environmental Authority in Panama. The team created a Land Use Conflict Identification Strategy (LUCIS) model based on land cover maps for 2019 and 2029 that were created in term I using imagery from Landsat 8 Operational Land Imager (OLI). With partner input, the team applied weights to different objectives and combined suitability maps to identify areas of potential biodiversity conflict. Additionally, the team created a Short-term Forest Change (SFTC) Tool using Terra Moderate Resolution Imaging Spectroradiometer, Landsat 8 OLI, and Sentinel-2 Multispectral Instrument to help the partners identify areas of immediate, major forest changes. The LUCIS model indicated higher agricultural growth when compared to the ecological category.

Ecological Forecasting↗
NASA NTRS2020

Costa Rica & Panama Ecological Forecasting II: Identifying Current and Future Areas of Environmental Concern in La Amistad International Park to Inform Resource Management

Seven percent of all scientifically known life forms lie within the 202,230 square miles of Central America, making this area ecologically unique and increasing the need for environmental management. The Mesoamerican Biological Corridor forms a conservation partnership throughout Central America to establish a forested corridor of over 600 protected areas. Although conservation programs exist, deforestation still afflicts the area, putting strain on these diverse ecosystems. La Amistad International Park in southern Costa Rica and northern Panama in particular faces conflicting land use changes. Expanding agricultural development and urbanization, combined with concern over indigenous land rights, have raised questions about the implementation of sustainability goals and communication strategies within the region. To help address these issues, the NASA DEVELOP Costa Rica & Panama Ecological Forecasting II team continued a partnership with the Ministry of Environment and Energy in Costa Rica and the National Environmental Authority in Panama. The team created a Land Use Conflict Identification Strategy (LUCIS) model based on land cover maps for 2019 and 2029 that were created in term I using imagery from Landsat 8 Operational Land Imager (OLI). With partner input, the team applied weights to different objectives and combined suitability maps to identify areas of potential biodiversity conflict. Additionally, the team created a Short-term Forest Change (SFTC) Tool using Terra Moderate Resolution Imaging Spectroradiometer, Landsat 8 OLI, and Sentinel-2 Multispectral Instrument to help the partners identify areas of immediate, major forest changes. The LUCIS model indicated higher agricultural growth when compared to the ecological category.

Ecological Forecasting↗
NASA NTRS2020

Former Central Heat Plant, SWMU 045 Implementation Work Plan Kennedy Space Center, Florida

This Implementation Work Plan (IWP) presents detailed design elements for the air sparging (AS) Interim Measure (IM) design provided in the IM Work Plan (IMWP) within the High Concentration Plume (HCP) at the Former Central Heat Plan (CHP) located at Kennedy Space Center (KSC), Florida. The IMWP presented an approach to implement an AS IM to reduce chlorinated volatile organic compound concentrations to concentrations that facilitate a transition to long-term monitoring. CHP has been designated Solid Waste Management Unit 045 under KSC’s Resource Conservation and Recovery Act Corrective Action Program.

Christopher J Pike↗
NASA NTRS2021

Hydrocarbon Burn Facility SWMU 007 Interim Groundwater Monitoring Report Kennedy Space Center, Florida

This Interim Groundwater Monitoring (IGWM) Report presents the findings of IGWM activities completed in November/December 2020 for the Volatile Organic Compound (VOC) Area of the Hydrocarbon Burn Facility (HBF) at Kennedy Space Center (KSC), Florida. HBF has been designated as Solid Waste Management Unit 007 under the KSC Resource Conservation and Recovery Act Corrective Action Program.

Jennifer Buel↗
NASA NTRS2021

Components Cleaning Facility, SWMU 030 Eastern High-Concentration Plume Area Implementation Work Plan Kennedy Space Center, Florida

This Implementation Work Plan (IWP) presents detailed design elements and coordination specifics to implement an air sparging (AS) Interim Measure (IM) to remediate groundwater at the Components Cleaning Facility (CCF), Eastern High Concentration Plume (HCP) Area located at Kennedy Space Center (KSC), Florida. The objective of the CCF East IM is to remediate groundwater where trichloroethene, cis-1,2-dichloroethene, and vinyl chloride concentrations exceed Florida Department of Environmental Protection Natural Attenuation Default Criteria (NADC) (identified as the HCP) via AS and to transition to monitored natural attenuation. CCF has been designated Solid Waste Management Unit 030 under KSC’s Resource Conservation and Recovery Act Corrective Action Program.

James Lloyd↗
NASA NTRS2022

Hydrocarbon Burn Facility SWMU 007 Interim Groundwater Monitoring Report Kennedy Space Center, Florida

This Interim Groundwater Monitoring (IGWM) Report presents the findings of IGWM activities completed in November 2021 along with an October 2021 direct push technology (DPT) investigation to confirm plume stability for the Volatile Organic Compound (VOC) Area of the Hydrocarbon Burn Facility (HBF) at Kennedy Space Center (KSC), Florida. HBF has been designated as Solid Waste Management Unit 007 under the KSC Resource Conservation and Recovery Act Corrective Action Program.

Jennifer Buel↗
NASA NTRS2023

Components Refurbishment and Chemical Analysis Facility, Hot Spot 1 SWMU #041 Year 3 Annual Performance Monitoring Report Kennedy Space Center, Florida

This Year 3 Annual Performance Monitoring Report (PMR) presents the operations, maintenance, and monitoring activities for the Hydraulic Containment System (HCS) Interim Measure (IM) at the Components Refurbishment and Chemical Analysis (CRCA) facility located at John F. Kennedy Space Center (KSC), Florida. The primary objective of the HCS is to attain hydraulic control of the dissolved-phase chlorinated volatile organic compound (CVOC) plume, with the secondary objective to reduce concentrations of CVOCs in the high-concentration plume to support transition to monitored natural attenuation (MNA). CRCA has been designated Solid Waste Management Unit 041 under the KSC Resource Conservation and Recovery Act Corrective Action Program. The timeframe for activities documented in this Year 3 PMR extends from September 2021 through October 2022. Baseline sampling activities were completed in June 2019, and full-scale startup of the HCS IM was completed in July-August 2019. The operational runtime of the HCS for the Year 3 reporting period was approximately 91%, with the majority of downtime attributed to system maintenance and repair. This is generally consistent with Year 1 and Year 2 runtimes of 85% and 92%, respectively. To help reduce downtime, an anti-scaling amendment, Redux 390, has been used to reduce scaling and help maintain system design parameters. Over nine million gallons of groundwater were treated during Year 3 of HCS operations, and concentrations of the site’s contaminants of concern (trans-1,2-dichloroethene and vinyl chloride) have been reduced by over 97%. This PMR describes the activities that were performed during Year 3 to operate and monitor the HCS IM, which includes three extraction wells, seven injection wells, and conveyance piping to a modular structure containing the control panel and an air stripper. Influent and effluent sampling results from the air stripper show that the system is operating as designed and is reducing concentrations of contaminants of concern to below detection limits. In addition to HCS operation, this PMR also discusses performance monitoring that has been implemented to assess progress of the HCS IM and overall plume conditions through scheduled groundwater (quarterly and semi-annual) and sub-slab soil gas (quarterly) sampling and analysis. Two ambient air samples were also collected on a quarterly basis in the vicinity of the modular structure and the paved driveway east of the Solvent Reclamation Area during routine operation and maintenance (O&M) activities to ensure safe breathing zone air quality for on-site personnel. All sub-slab soil gas and ambient air sampling conducted during the Year 3 operational period showed results below applicable regulatory air screening limits. Predictions made during the Year 2 groundwater model updates were in close correlation to post Year 3 plume conditions. Therefore, it can be assumed that the projected path remains valid for transition to MNA in one to two years of continuous HCS operation. The contents of this Year 3 PMR were presented during the February 2023 KSC Remediation Team meeting, where Team consensus was reached on several items including continued O&M of the HCS, and continued monitoring of groundwater, ambient air, and sub-slab soil gas. Replacement of MW0019 and VMP04 was also recommended, as well as additional direct-push technology sampling to further delineate the downgradient plume and confirm overall site-wide low-concentration plume boundaries. Sampling for per- and polyfluoroalkyl substances at CRCA is ongoing and will be submitted under separate cover.

K. Alex Murphy↗
NASA NTRS2024

Former Central Heat Plant SWMU 045 Year 2 Air Sparge System Performance Monitoring Report

This Air Sparge (AS) Performance Monitoring (PM) Report (PMR) presents Year 2 operation, maintenance, and monitoring (OM&M) activities, PM results, and monitoring well installations supporting the AS Interim Measure (IM) at the Former Central Heat Plant (CHP) at Kennedy Space Center (KSC), Florida. CHP has been designated Solid Waste Management Unit 045 under the KSC Resource Conservation and Recovery Act Corrective Action Program. An AS IM was installed at CHP between 2019 and 2021, which included the installation of an AS system to treat a chlorinated solvent groundwater plume. Contaminants of concern (COCs) identified at CHP for the AS IM include tetrachloroethene (PCE), trichloroethene (TCE), cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The completed AS system includes a network of 267 AS wells, which treat approximately 1.3 acres of contaminated groundwater. “Hot” compressor technology is used to treat the source zone, while a “cold” compressor is used to treat two hot spot (HS) areas (HS1 and HS2) and the high concentration plume (HCP). The AS system began operation in June-July 2021 and this document includes Year 2 of operation. The overall runtimes for the AS system for the Year 2 reporting period (October 2022 to September 2023) were approximately 69 percent for the cold trailer and 71 percent for the hot trailer. Air samples and vapor screening results collected during the reporting period showed concentrations less than applicable human health and air emissions permit criteria. Groundwater performance monitoring results show that AS treatment continues to be effective in reducing COC concentrations at CHP. At the shallow interval, COC concentrations were all non-detect, less than, or met their respective State of Florida Groundwater Cleanup Target Levels (GCTLs) at the end of Year 2 in September 2023. In the deep interval, 10 of the 15 PM wells detected COCs greater than their respective GCTLs, with two of these wells also exceeding the Natural Attenuation Default Concentration for VC. Based on Year 2 OM&M and PM results, continued operation of the AS system is required to meet the IM objective. It is therefore recommended to continue with AS IM operations at CHP with the following plan for Year 3.

Kevin Alex Murphy↗
NASA NTRS2024

Components Refurbishment and Chemical Analysis Facility, Hot Spot 1 Solid Waste Management Unit #041 Year 4 Annual Performance Monitoring Report Kennedy Space Center, Florida

This Year 4 Annual Performance Monitoring Report (PMR) presents the operations, maintenance, and monitoring activities for the Hydraulic Containment System (HCS) Interim Measure (IM) at the Components Refurbishment and Chemical Analysis (CRCA) facility located at John F. Kennedy Space Center (KSC), Florida. The primary objective of the HCS is to attain hydraulic control of the dissolved-phase chlorinated volatile organic compound (CVOC) plume, with the secondary objective to reduce concentrations of CVOCs in the high-concentration plume to support transition to monitored natural attenuation (MNA). CRCA has been designated Solid Waste Management Unit 041 under the KSC Resource Conservation and Recovery Act Corrective Action Program. The timeframe for activities documented in this Year 4 PMR extends from November 2022 through September 2023. Baseline sampling activities were completed in June 2019, and full-scale startup of the HCS IM was completed in July-August 2019. The operational runtime of the HCS for the Year 4 reporting period was approximately 94%, with the majority of downtime attributed to associated groundwater sampling events, maintenance, and Hurricane Nicole. Almost five million gallons of groundwater were treated during Year 4 of HCS operations, and concentrations of the site’s contaminants of concern (trans-1,2-dichloroethene and vinyl chloride) have been reduced by over 99%. This PMR describes the activities that were performed during Year 4 to operate and monitor the HCS IM, which includes three extraction wells, seven injection wells, and conveyance piping to a modular structure containing the control panel and an air stripper. Influent and effluent sampling results from the air stripper show that the system is operating as designed and is reducing concentrations of contaminants of concern to below detection limits. In addition to HCS operation, this PMR also discusses performance monitoring that has been implemented to assess progress of the HCS IM and overall plume conditions through scheduled groundwater (quarterly and semi-annual) and sub-slab soil gas (quarterly) sampling and analysis. Two ambient air samples were also collected on a quarterly basis in the vicinity of the modular structure and the paved driveway east of the Solvent Reclamation Area during routine operation and maintenance (O&M) activities to ensure safe breathing zone air quality for on-site personnel. All sub-slab soil gas and ambient air sampling conducted during the Year 4 operational period showed results below applicable regulatory air screening limits. Predictions made during the Year 2 groundwater model updates were in close correlation to post Year 4 plume conditions. A supplemental DPT study conducted in 2022 and 2023. This study indicated that low-concentration plume conditions, where concentrations exceed State of Florida Groundwater Cleanup Target Levels, expanded westward to Kennedy Parkway North and northward to the vicinity of the railroad tracks. Based on these results, recommendations were made to install 14 wells to monitor the downgradient and boundary conditions of the expanded LCP. The contents of this Year 4 PMR were presented during the November 2023 KSC Remediation Team meeting, where Team consensus was reached on several items including continued O&M of the HCS, and continued monitoring of groundwater, ambient air, and sub-slab soil gas. Sampling for per- and polyfluoroalkyl substances at CRCA is ongoing and will be submitted under separate cover.

K. Alex Murphy↗
NASA NTRS2024

Area South of K7-516, SWMU 100 Performance Monitoring Report Kennedy Space Center, Florida

This Performance Monitoring Report (PMR) presents operations, maintenance, and monitoring information and performance monitoring results for the air sparging (AS) groundwater Interim Measure at the Area South of K7-516 (516S) located at Kennedy Space Center (KSC), Florida. AS expansion activities are also included in this PMR. The 516S site has been designated Solid Waste Management Unit 100 under the KSC Resource Conservation and Recovery Act Corrective Action Program. The timeframe for activities included in this report extends from January 1, 2023, through December 31, 2023.

Mark J. Jonnet↗
NASA NTRS2024

Central Park Ecological Conservation: Assessing Tree Health Conditions in New York City’s Central Park with NASA Earth Observation Data

The Central Park Conservancy stewards New York City’s iconic Central Park with a mission to preserve the park for all. This mission is complicated by the spread of Dutch elm disease (DED) which has threatened the culturally and ecologically significant American elm tree (Ulmus americana). Central Park is home to one of the largest and last remaining urban concentrations of American elm and the Conservancy currently protects them through integrated pest management. This paper discusses an interdisciplinary feasibility study that assessed the application of NASA Earth observations from 2014 to 2023 to detect changes in forest phenology possibly related to DED. Landsat 8 and 9 imagery was used to calculate multiyear time series of the Normalized Difference Vegetation Index (NDVI) and quantify changes in land surface phenology for a given year. A pixel-based logistic regression analysis was performed using changes in NDVI, tree site locations, and recorded occurrences of trees infected with DED as inputs. The results of this analysis show that changes in NDVI derived from Landsat data are capable of detecting unhealthy tree canopies with 71% precision and healthy tree canopies with 41% precision. The study had uncertainties and limitations due to the spatial and temporal resolutions of Landsat, the natural variability in land surface phenology and NDVI, and the attempt to detect disease impacts while disease prevention and mitigation is occurring. As is, the findings of this study and its methods provide managers with an approach for integrating Earth observations to make more informed decisions in the application and timing of urban forest management activities.

Central Park↗
NASA NTRSDate not supplied

Assessing Tree Health Conditions in New York City’s Central Park with Earth Observation Data

The Central Park Conservancy stewards New York City’s iconic Central Park with a mission to preserve the park for all. This mission is complicated by the spread of Dutch elm disease (DED) which has threatened the culturally and ecologically significant American elm tree (Ulmus americana). Central Park is home to one of the largest and last remaining urban concentrations of American elm and the Conservancy currently protects them through integrated pest management. This project is an interdisciplinary feasibility study that assessed the application of NASA Earth observations from 2014 to 2023 to detect changes in forest phenology possibly related to DED. Landsat 8 and 9 imagery was used to calculate a multiyear time series of the Normalized Difference Vegetation Index (NDVI) and quantify changes in land surface phenology. A pixel-based logistic regression analysis was performed using changes in NDVI, tree site locations, and recorded occurrences of trees infected with DED as inputs. The results of this analysis show that changes in NDVI derived from Landsat data are capable of detecting unhealthy tree canopies with 71% precision and healthy tree canopies with 41% precision. The study had uncertainties and limitations due to the spatial and temporal resolutions of Landsat, the natural variability in land surface phenology and NDVI, and the attempt to detect disease impacts while disease prevention and mitigation are occurring. As is, the findings of this study and its methods provide managers with an approach for integrating Earth observations to make more informed decisions in the application and timing of urban forest management activities.

John Hocknell↗
NASA NTRS2021

Distribution and Relative Abundance of Scalloped (Sphyrna lewini) and Carolina (S. gilberti) Hammerheads in the Western Atlantic Ocean

The scalloped hammerhead (Sphyrna lewini) and its cryptic congener, Carolina hammerhead (S. gilberti), are sympatrically distributed in the western North Atlantic Ocean. Because the species are indistinguishable based on external morphology, little research focused on Carolina hammerheads exists. In this study, the distribution of Carolina hammerheads in waters of the United States off the east coast (U.S. Atlantic) and Gulf of Mexico (Gulf) was examined and their abundance relative to scalloped hammerheads assessed by genetically identifying 1,232 individuals using diagnostic single nucleotide polymorphisms. Both species were found in the U.S. Atlantic, where 27% of individuals were Carolina hammerheads, but only scalloped hammerheads were identified in the Gulf. In Bulls Bay, SC, a well-known hammerhead nursery, assessment of relative abundance from May to September showed scalloped hammerheads were more abundant May-June and Carolina hammerheads more abundant July-September. Results of this study suggest Carolina hammerheads have a spatially limited distribution in the western North Atlantic and highlight the importance of Bulls Bay as a nursery for the species. In addition, the results suggest Carolina hammerheads may comprise a non-trivial proportion of what is considered the U.S. Atlantic scalloped hammerhead stock and should be considered in future decisions regarding management of the hammerhead complex.

Sympatric↗
NASA NTRS1981

Test results of flight guidance for fuel conservative descents in a time-based metered air traffic environment

The NASA developed, implemented, and flight tested a flight management algorithm designed to improve the accuracy of delivering an airplane in a fuel-conservative manner to a metering fix at a time designated by air traffic control. This algorithm provides a 3D path with time control (4D) for the TCV B-737 airplane to make an idle-thrust, clean configured (landing gear up, flaps zero, and speed brakes retracted) descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path is calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithms are described and flight test results are presented.

Knox, C. E.↗