Review of Automatic Speech Recognition Methodologies

DTFACT-14-D-00004,692M152240001This report highlights the crucial role of Automatic Speech Recognition (ASR) techniques in enhancing safety for air traffic control (ATC) in terminal environments. ASR techniques facilitate efficient and accurate transcription of verbal communications, reducing the likelihood of errors. The report also details the evolution of ASR technologies, converging to machine learning approaches from Hidden Markov Models (HMMs), Deep Neural Networks (DNNs) to End-to-End models. Finally, the report details the latest advancements in ASR techniques, focusing on transformer-based models that have outperformed traditional ASR approaches and achieved state-of-the-art results on ASR benchmarks

Data-Driven Analysis of Departure Procedures for Aviation Noise Mitigation

13-C-AJFF-GIT-054This is an open access article under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) license https://creativecommons.org/licenses/by/4.0/. The paper first appeared in Engineering Proceedings. Citation: Bhanpato, J.; Puranik, T.G.; Mavris, D.N. Data-Driven Analysis of Departure Procedures for Aviation Noise Mitigation. Eng. Proc. 2021, 13, 2. https://doi.org/10.3390/ engproc2021013002The mitigation of aviation environmental effects is one of the key requirements for sustainable aviation growth. Among various mitigation strategies, Noise Abatement Departure Procedures (NADPs) are a popular and effective measure undertaken by several operators. However, a large variation in departure procedures is observed in real operations. This study demonstrates the use of OpenSky ADS-B departure data for comparison and quantification of the differences in trajectories and the resulting community noise impact between real-world operations and NADPs. Trajectory comparison is accomplished in order to gain insights into the similarity between NADPs and real-world procedures. Clustering algorithms are employed to identify representative departure procedures, enabling efficient high-fidelity noise modeling. Finally, noise results are compared in order to quantify the difference in environmental impacts arising from variability in real-world trajectories. The methodology developed enables more efficient and accurate environmental analyses, thereby laying the foundation for future impact assessment and mitigation efforts

Mission Analysis and Aircraft Sizing of a Hybrid-Electric Regional Aircraft

The purpose of this study was to explore advanced airframe and propulsion technologies for a small regional transport aircraft concept (approximately 50 passengers), with the goal of creating a conceptual design that delivers significant cost and performance advantages over current aircraft in that class. In turn, this could encourage airlines to open up new markets, reestablish service at smaller airports, and increase mobility and connectivity for all passengers. To meet these study goals, hybrid-electric propulsion was analyzed as the primary enabling technology. The advanced regional aircraft is analyzed with four levels of electrification, 0 percent electric with 100 percent conventional, 25 percent electric with 75 percent conventional, 50 percent electric with 50 percent conventional, and 75 percent electric with 25 percent conventional for comparison purposes. Engine models were developed to represent projected future turboprop engine performance with advanced technology and estimates of the engine weights and flowpath dimensions were developed. A low-order multi-disciplinary optimization (MDO) environment was created that could capture the unique features of parallel hybrid-electric aircraft. It is determined that at the size and range of the advanced turboprop: The battery specific energy must be 750 watt-hours per kilogram or greater for the total energy to be less than for a conventional aircraft. A hybrid vehicle would likely not be economically feasible with a battery specific energy of 500 or 750 watt-hours per kilogram based on the higher gross weight, operating empty weight, and energy costs compared to a conventional turboprop. The battery specific energy would need to reach 1000 watt-hours per kilogram by 2030 to make the electrification of its propulsion an economically feasible option. A shorter range and/or an altered propulsion-airframe integration could provide more favorable results

The Environmental Design Space

05-CNE-GIT, Amendment Nos. 001, 003 and 00703-C-NE-MIT, Amendment Nos. 011, 015, 018, 022, 025, and 03407-C-NE-GIT, Amendment No. 00106-C-NE-MIT, Amendment No. 004This work was funded by the FAA under PARTNER (a FAA/NASA-TC sponsored Center of Excellence) under Grant Nos: 05-CNE- GIT, Amendment Nos. 001, 003 and 007, 03-C-NE-MIT, Amendment Nos. 011, 015, 018, 022, 025, and 034, 07-C-NE-GIT, Amendment No. 001,06-C-NE-MIT, Amendment No. 004. Citation: Kirby, M., and Mavris, D., The Environmental Design Space, 26th International Congress of the Aeronautical Sciences, 2008. ICAS-2008-4.7.3.The U.S. Federal Aviation Administration Office of Environment and Energy, in collaboration with Transport Canada and the National Aeronautics and Space Administration, is developing a comprehensive suite of software tools that will allow for thorough assessment of the environmental effects of aviation. This paper will provide an overview of the EDS program and its capabilities for capturing environmental interdependencies

Rotorcraft Wire Strike Prevention and Protection: Wire Database Creation, Sensor Package Design, Wire Cutter Modeling, Data Fusion, and Helicopter Operators\u2019 Inputs

Wire strikes have been one of the most common sources of helicopter accidents in the past seven years. The sizes of poles and wires make it difficult for rotorcraft pilots to see them in-flight. This motivates the need to provide pilots with various tools and information to prevent accidents related to wire strikes. In this report, we present different ways to enhance the safety of helicopters when operating at altitudes where wire strikes are possible. The first way enables the prediction of the wire grid from street view and satellite imagery using deep learning techniques. The outcome is a dataset of predicted wire locations that may be displayed in 2D or 3D on moving maps of electronic flight bags or in the cockpit avionics. The second way of preventing rotorcraft wire strikes is the development of a 360-degree radar system able to detect wires in-flight at a minimum distance of 50\u2019 from any part of the rotorcraft. The third way is to fuse the information from the predicted wire database with the measured data from the sensor in order to improve the predicted wire locations in real time. A fourth way is to develop a new wire cutter system able to cut various sizes of cables when installed on lightweight helicopters. To do so, we develop a physics-based modeling and simulation environment where various types of helicopters, wires, and cutter systems may be implemented and assessed. Finally, a questionnaire was created and distributed to helicopter operators to determine how to prevent wire strike incidents and accidents based on their operational experience

An Investigation of the Potential Implications of a CO2 Emission Metric on Future Aircraft Designs

07-CNE-GIT-001 (Amendment No. 015)09-C-NEGIT-001 (Amendment No. 003)DTFAWA-05-D-00012 (Task Order No. 0007)This work was funded by the FAA under Partnership for AiR Transportation Noise and Emissions Reduction, PARTNER: a FAA/NASA/Transport Canada sponsored Center of Excellence, under Award Nos.: 07-CNE-GIT-001 (Amendment No. 015), 09-C-NEGIT-001 (Amendment No. 003), and DTFAWA-05-D-00012 (Task Order No. 0007). Citation: Nam T., Kirby M., Burdette G., Lim D., Isley S., Bonnefoy P., Hansman R. J., Hileman J., Waitz I., Yutko B., \u201cAn Investigation of the Potential Implications of a CO2 Emission Metric on Future Aircraft Designs,\u201d International Council of the Aeronautical Sciences (ICAS), Nice, France, Sept. 2010.Shifts in vehicle design trends due to aviation CO2 emission metrics are explored. The combined effects of traditional performance and stringent environmental constraints on several vehicle design spaces are observed, in the presence of future technologies. Potential design implications and unintended consequences of candidate metrics are identified

En Route Traffic Optimization to Reduce Environmental Impact

03-C-NE-MIT, Amendment Nos. 028 and 30This work was funded by the U.S. Federal Aviation Administration Office of Environment and Energy, under Grant 03-C-NE-MIT, Amendment Nos. 028 and 30.National Airspace System congestion causes air traffic delays that create unnecessary costs for passengers, airlines, and air transportation dependent businesses. In addition to financial impacts, delays also create environmental costs