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Division Highlights

Phase 2 Rudder Control System Requirements Experiment on the Vertical Motion Simulator: A simulation study was conducted on the VMS to develop handling qualities criteria and guidance for rudder control system design in large transport aircraft. This was the second in a series of three experiments sponsored by the FAA and conducted by Hoh Aeronautics, Inc. A particular area of interest in these experiments is to identify design factors that would minimize the tendency for rudder over-control that could lead to departure from controlled flight and structural failure. For this experiment, the transport cab (TCAB) on the VMS was fitted with a standard wheel/column/rudder pedal flight controls, and a throttle quadrant. The research force-feel systems on the VMS were upgraded to meet the needs of this project including very high force-gradients (over 1,000 lbs per inch) and precision force breakouts and displacement deadbands. The rudder pedal feel and displacements were adjusted in real-time based on the requirements of the experimental configurations. The primary test variations included three different rudder control system architectures, representative of systems currently in service in the commercial airline fleet, and a large matrix of pedal force-feel characteristics, including different pedal displacements, force breakouts, and linear and non-linear force-displacement gradients. The secondary test matrix investigated an improved yaw damper implementation, the use of additional rudder control power, and the Holdback Effect (a subtle difference in the ratio of pedal friction to force breakout). The various rudder system variations were evaluated using a task that required the pilot to maintain straight and level flight in the presence of large rolling gusts through aggressive use of the rudder. The VMS motion algorithms were optimized to provide realistic lateral acceleration and yaw motion cues to the pilot. Twelve evaluation pilots, including some from the FAA, Boeing, and Airbus, evaluated all the primary and secondary test configurations over a three-week period — a total of approximately 1,000 simulation runs. Preliminary analysis of the results suggests that systems with larger pedal displacements are less prone to over-control. A third simulation experiment is expected to further understand critical issues with rudder control system design and develop updated certification requirements.

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Upgrading the Advanced Cockpit Flight Simulator: The Advanced Concepts Flight Simulator (ACFS) will be upgraded to support the anticipated research needs of the NextGen Airspace and Airportal programs. Planned upgrades include improved simulator architecture, an accurate aerodynamic model of a representative commercial aircraft for the 2025 time frame, and a more modular infrastructure including high-fidelity flight management system (FMS) and display systems. The multi-phase implementation plan will address the near and far term requirements of the NextGen Program researchers without interfering with ongoing research activities. Phase 1 will integrate the GE Aviation/Smiths Flight Management System (SFMS) with the ACFS to provide a FANS-1/A capability with CPDLC and ACARS datalink. This capability will facilitate NextGen Airspace research while minimizing any impact on on-going research into intelligent resilient flight control systems by the Aviation Safety Program. This phase will be completed in FY09. Phase 2 will address key infrastructure issues in the ACFS architecture (rehost) and build a testbed environment to support Phase 3 development. This effort will produce a hardware and software "SimLabs Standard Configuration" for real-time hosts, making the Vertical Motion Simulator (VMS) and ACFS labs available for interchangeable studies. An ACFS testbed environment will be developed to integrate and test hardware and software components. This phase will be completed in FY10. Phase 3 is expected to be a multi-year effort to integrate new hardware and software on the testbed and then on the ACFS cockpit and motion system in FY11 or FY12. A significant component in this effort is the integration of a Boeing 737-800W aircraft model that will provide the researchers with an accurate performance model of an aircraft that will be prominent in the national airspace in the year 2025.

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Ames-Langley Automated Separation Assurance Meeting: A joint Ames-Langley meeting of separation-assurance researchers was held to examine two candidate algorithms for automated separation assurance: one tactical and one strategic. In the first of what is expected to be a series of such meetings, Dr. Heinz Erzberger (Stanford, UC Santa Cruz) and Dr. Karen Heere (UC Santa Cruz) traveled to Langley Research Center to lead a discussion of their concept, approach, and development of the Tactical Separation Assisted Flight Environment, or TSAFE, tactical conflict-resolution algorithm and the "autoresolver" strategic conflict-resolution algorithm. The day-long meeting produced good questions and discussion, and the researchers received valuable feedback in the process. Future joint meetings are expected to focus on other candidate algorithms and concepts currently under research. The intent of this interchange is to improve communication within the NASA separation-assurance research community, strengthen the technical merit of our research products, and lay the foundation for developing joint, hybrid concepts that leverage the strengths of our various candidate approaches.

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Classification of 2006 Days of Operation in the Air Transpiration System: Metron Aviation delivered a report that classified days of operation in the Air Transportation System in 2006. The classification was performed using FAA data that measures the traffic and weather conditions for each day of operation. Eight groups of days were identified. While days within each group have similar weather and traffic conditions, days from different groups have different ones. The classification will significantly reduce the number of simulations required to calculate the annualized benefits of future air traffic management concepts. In general, this calculation requires one or more simulations for each of the 365 days in a year. This is because weather and traffic conditions, which greatly influence future concept benefits, are unique for each day. With the classification, only one or more days from each of the eight groups will be simulated. Annualized benefits will be calculated by multiplying the benefits for each day by the frequency that that type of day occurred during 2006.

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Aviation Systems Division Helping to Create an ATM-weather Integration Plan for the JPDO NextGen Executive Weather Panel: An Aviation Systems division representative met with members of the JPDO Weather Integration team in Washington, DC to begin development of an ATM-Weather Integration plan. This plan is expected to be presented to the NextGen Executive Weather Panel in September 2009. Also in attendance were representatives from the DoD, FAA, NOAA. MITRE, MIT/LL, National Center for Atmospheric Research, AvMet, Delta Airlines, Metron Aviation, Mosaic ATM, and Northwest Airlines. Three sub-teams will contribute to the writing of this plan. Subteam-1 will develop concepts of use, gather and analyze weather requirements and analyze weather forecast capabilities. Subteam-2 will define how to translate weather information to determine airspace capacity and methods to address risk in weather related decision-making. Subteam-3 will align elements of this plan with other relevant plans and reports and provide coordination among other ATM groups. The subteams expect to complete a first draft by the end of February 2009.

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Last Updated: November 7, 2018

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