Conformance Monitoring Approaches in Current and Future Air Traffic Control Environments

Conformance monitoring is a core task in Air Traffic Control (ATC) operations to determine whether aircraft are adhering to assigned trajectories. This is important for many reasons, including to ensure that tactical collision avoidance maneuvers are properly executed; strategic conflict detection & resolution schemes are valid and security around sensitive locations is maintained. In today’s ATC environment, controllers monitor for conformance via radar systems that primarily provide positional information. As a result, non-conformance criteria are generally based on positional deviations from the assigned trajectory [1] or penetration of restricted airspace such as the No Transgression Zone (NTZ) on PRM approaches [2]. Future ATC surveillance systems such as Automatic Dependant Surveillance (ADS) should provide access to additional aircraft state information which could be used for more effective conformance monitoring. However, at present there is a lack of clear rationale for which states should be surveilled and how they would be used to enable conformance monitoring to be performed at a level appropriate for future operational requirements. This paper describes a framework for this purpose that poses the conformance monitoring task as a model-based fault detection problem.This work was supported by NASA Langley Research Center under grant NAG1-02006

Air Carrier Flight Operations

Most air carriers operate under a system of prioritized goals including safety, customer service (on-time departures and arrivals) and operating economics. The flight operations department is responsible for the safe and efficient movement of passengers and/or cargo which ultimately generate the revenue for the airline. The major components needing to be coordinated for any given flight include the aircraft and support equipment, cockpit and cabin crews (together known as the “flight crew”), maintenance, and ground service personnel. Although the maintenance and ground crew activities are critical to support flight operations, the emphasis in this document is on the regulation and scheduling of the flight crews to conduct a given flight, followed by a detailed discussion of the activities of flight crews during the phases of a typical revenue flight sequence. Note that this chapter does not attempt to address detailed airmanship and flight maneuvering topics and only includes such information in the context of the overall flight operation. However, specific flight procedures that may have a direct impact on the operational goals are included to aid in understanding the nature and complexity of the factors involved

Human Factors Implications of Continuous Descent Approach Procedures for Noise Abatement

Abstract Continuous Descent Approach (CDA) procedures can be effective at reducing aircraft noise in the vicinity of airports. The human factors implications for the air traffic controller of transitioning from conventional to CDA procedures are addressed in this paper. Different types of CDA procedures are introduced and models are developed of the controller tasks undertaken during current approach operations. The models are used to perform cognitive difference analyses to highlight the implications of using CDA procedures, particularly with respect to differences in intent, controllability and structure-based abstractions in the lateral, vertical and speed domains. An experiment is presented which probes the cognitive implications of changing speed profiles during the approach, which was one of the key differences between the procedures identified in the cognitive difference analysis. Based on the results, recommendations are made for CDA procedure design with a view to easing transition and controller acceptance

Environmental effects of aircraft operations and airspace charging regimes. Final report

Project aim and outline: There has been anecdotal evidence that differences in airspace charging regimes influence airlines’ preferred routes and flight plans through European airspace. Routing aircraft over longer distances in order to reduce direct operating costs has a range of fuel burn and greenhouse gas emission consequences that have yet to be adequately quantified. The aim of this project is to study the environmental costs of different airspace charging regimes in Europe to ascertain whether the level of route charges that are levied for performing a flight affects the route that is flown between specific origin/destination pairs. Through a strategic assessment of a sample of airline flight plans and discussion with stakeholders, the study investigates the drivers of these apparently inefficient flight plans, quantifies the proportion of European routes that are affected (and the additional distances that are travelled) and identifies the greenhouse gas emission (focussing on carbon dioxide) implications of the observed behaviours

Climate related air traffic management. Final report. Assessing the role of air traffic management in reducing environmental impacts of aviation

Climate related air traffic management. Final report. Assessing the role of air traffic management in reducing environmental impacts of aviatio

Eco‐evolutionary dynamics in response to selection on life‐history

Understanding the consequences of environmental change on ecological and evolutionary dynamics is inherently problematic because of the complex interplay between them. Using invertebrates in microcosms, we characterise phenotypic, population and evolutionary dynamics before, during and after exposure to a novel environment and harvesting over 20 generations. We demonstrate an evolved change in life-history traits (the age- and size-at-maturity, and survival to maturity) in response to selection caused by environmental change (wild to laboratory) and to harvesting (juvenile or adult). Life-history evolution, which drives changes in population growth rate and thus population dynamics, includes an increase in age-to-maturity of 76% (from 12.5 to 22 days) in the unharvested populations as they adapt to the new environment. Evolutionary responses to harvesting are outweighed by the response to environmental change (~ 1.4 vs. 4% change in age-at-maturity per generation). The adaptive response to environmental change converts a negative population growth trajectory into a positive one: an example of evolutionary rescue. © 2013 John Wiley & Sons Ltd/CNRS

Demonstration of Reduced Airport Congestion Through Pushback Rate Control

Airport surface congestion results in significant increases in taxi times, fuel burn and emissions at major airports. This paper presents the field tests of a control strategy to airport congestion control at Boston Logan International Airport. The approach determines a suggested rate to meter pushbacks from the gate, in order to prevent the airport surface from entering congested states and reduce the time that flights spend with engines on while taxiing to the runway. The field trials demonstrated that significant benefits were achievable through such a strategy: during eight four-hour tests conducted during August and September 2010, fuel use was reduced by an estimated 12,000-15,000 kg (3,900-4,900 US gallons), while aircraft gate pushback times were increased by an average of only 4.3 minutes

Galactic contamination in the QMAP experiment

We quantify the level of foreground contamination in the QMAP Cosmic Microwave Background (CMB) data with two objectives: (a) measuring the level to which the QMAP power spectrum measurements need to be corrected for foregrounds and (b) using this data set to further refine current foreground models. We cross-correlate the QMAP data with a variety of foreground templates. The 30 GHz Ka-band data is found to be significantly correlated with the Haslam 408 MHz and Reich and Reich 1420 MHz synchrotron maps, but not with the Diffuse Infrared Background Experiment (DIRBE) 240, 140 and 100 micron maps or the Wisconsin H-Alpha Mapper (WHAM) survey. The 40 GHz Q-band has no significant template correlations. We discuss the constraints that this places on synchrotron, free-free and dust emission. We also reanalyze the foreground-cleaned Ka-band data and find that the two band power measurements are lowered by 2.3% and 1.3%, respectively.Comment: 4 ApJL pages, including 4 figs. Color figures and data at http://www.hep.upenn.edu/~angelica/foreground.html#qmap or from [email protected]

Near-Infrared Synchrotron Emission from Cas A

High energy observations of Cas A suggested the presence of synchrotron radiation, implying acceleration of cosmic rays by young supernova remnants. We detect synchrotron emission from Cas A in the near-infrared using Two Micron All Sky Survey (2MASS) and Palomar 200 inch PFIRCAM observations. The remnant is detected in J, H, and Ks bands, with Ks band brightest and J faint. In the J and H bands, bright [Fe II] lines (1.24um and 1.64um) are detected spectroscopically. The Palomar observations include Ks continuum, narrow-band 1.64um (centered on [Fe II]) and 2.12um (centered on H2(1-0)) images. While the narrow-band 1.64um image shows filamentary and knotty structures, similar to the optical image, the Ks image shows a relatively smooth, diffuse shell, remarkably similar to the radio image. The broad-band near-infrared fluxes of Cas A are generally consistent with, but a few tens of percent higher than, an extrapolation of the radio fluxes. The hardening to higher frequencies is possibly due to nonlinear shock acceleration and/or spectral index variation across the remnant. We show evidence of spectral index variation. The presence of near-infrared synchrotron radiation requires the roll-off frequency to be higher than 1.5e14 Hz, implying that electrons are accelerated to energies of at least 0.2 TeV. The morphological similarity in diffuse emission between the radio and Ks band images implies that synchrotron losses are not dominant. Our observations show unambiguous evidence that the near-infrared Ks band emission of Cas A is from synchrotron emission by accelerated cosmic-ray electrons.Comment: accepted by Ap

Circulating Folate Concentrations and Risk of Peripheral Neuropathy and Mortality: A Retrospective Cohort Study in the U.K

BACKGROUND: Folate deficiency may increase the risk of peripheral neuropathy but there is a paucity of data from large prospective studies examining this association. METHODS: Longitudinal analysis of electronic health records in The Health Improvement Network (THIN), a U.K. primary care database including 594,338 patients aged 18-70 years with a folate measurement and without a history of peripheral neuropathy. RESULTS: After a mean follow-up of 3.71 (standard deviation (SD) = 3.14) years, 1949 patients were diagnosed with peripheral neuropathy and 20,679 patients died. In those <40 years, compared to patients with folate ≥13.6 nmol/L, those with folate <6.8 (deficient) and 6.8-13.5 nmol/L (insufficient) had a hazard ratio (HR) for peripheral neuropathy of 1.83 (95% confidence intervals (CI) = 1.16-2.91) and 1.48 (95% CI = 1.04-2.08), respectively. There was no significant association between folate and peripheral neuropathy among those aged 41-70 years. Compared to patients with folate ≥ 13.6 nmol/L, folate <6.8 nmol/L was associated with a greater risk of death among all ages. CONCLUSION: Folate deficiency and insufficiency was associated with a greater risk of peripheral neuropathy among younger patients. This investigation should be replicated in other large datasets and it may be important to monitor peripheral neuropathy incidence after the introduction of mandatory folic acid fortification of flour in the U.K