9 research outputs found
Increasing Pilots Understanding of Future Automation State an Evaluation of an Automation State and Trajectory Prediction System
A pilot in the loop flight simulation study was conducted at NASA Langley Research Center to evaluate a trajectory prediction system. The trajectory prediction system computes a five-minute prediction of the lateral and vertical path of the aircraft given the current and intent state of the automation. The prediction is shown as a graphical representation so the pilots can form an accurate mental model of the future state. Otherwise, many automation changes and triggers are hidden from the flight crew or need to be consolidated to understand if a change will occur and the exact timing of the change. Varying dynamic conditions like deceleration can obscure the future trajectory and the ability to meet constraints, especially in the vertical dimension. Current flight deck indications of flight path assume constant conditions and do not adequately support the flight crew to make correct judgments regarding constraints. The study was conducted using ten commercial airline crews from multiple airlines, paired by airline to minimize procedural effects. Scenarios spanned a range of conditions that provided evaluation in a realistic environment with complex traffic and weather conditions. In particular, scenarios probed automation state and loss of state awareness. The technology was evaluated and contrasted with current state-of-the-art flight deck capabilities modeled from the Boeing 787. Objective and subjective data were collected from aircraft parameters, questionnaires, audio/video recordings, head/eye tracking data, and observations. This paper details findings about the trajectory prediction system including recommendations about further study
Piloted Simulator Evaluation Results of Flight Physics Based Stall Recovery Guidance
In recent studies, it has been observed that loss of control in flight is the most frequent primary cause of accidents. A significant share of accidents in this category can be remedied by upset prevention if possible, and by upset recovery if necessary, in this order of priorities. One of the most important upsets to be recovered from is stall. Recent accidents have shown that a correct stall recovery maneuver remains a big challenge in civil aviation, partly due to a lack of pilot training. A possible strategy to support the flight crew in this demanding context is calculating a recovery guidance signal, and showing this signal in an intuitive way on one of the cockpit displays, for example by means of the flight director. Different methods for calculating the recovery signal, one based on fast model predictive control and another using an energy based approach, have been evaluated in four relevant operational scenarios by experienced commercial as well as test pilots in the Vertical Motion Simulator at NASA Ames Research Center. Evaluation results show that this approach could be able to assist the pilots in executing a correct stall recovery maneuver
Nonlinear Femtosecond Pulse Reshaping in Waveguide Arrays
We observe nonlinear pulse reshaping of femtosecond pulses in a waveguide
array due to coupling between waveguides. Amplified pulses from a mode-locked
fiber laser are coupled to an AlGaAs core waveguide array structure. The
observed power-dependent pulse reshaping agrees with theory, including
shortening of the pulse in the central waveguide
Emerging Technologies for Airplane State Awareness and Prediction
Loss of control in flight (LOC-I) is consistently the leading cause of fatal aircraft accidents. A study of LOC accidents and incidents, commissioned by the Commercial Aviation Safety Team (CAST) identified a growing trend in loss of Airplane State Awareness (ASA) by the flight crew. This has led to recommended safety enhancements that include flight deck technologies with the potential of enhancing flight crew awareness of airplane energy state. The goal of this research is to develop and evaluate technologies that predict and assess the future aircraft energy state and auto-flight configuration, and provide appropriate alerting to anticipated problematic auto-flight inputs, with the aim of enhancing pilots situational awareness
Piloted Simulator Evaluation of Maneuvering Envelope Information for Flight Crew Awareness
This paper discusses the implementation and evaluation of an efficient method for estimating safe aircraft maneuvering envelopes. A Bayesian approach is used to produce a deterministic algorithm for estimating aerodynamic system parameters from existing noisy sensor measurements, which are then used to estimate the trim envelope through efficient high-fidelity model-based computations of attainable equilibrium sets. The safe maneuverability limitations are extended beyond the trim envelope through a robust reachability analysis derived from an optimal control formulation. The trim and maneuvering envelope limits are then conveyed to pilots through three axes on the primary flight display. These display features were evaluated in the Advanced Concepts Flight Simulator at NASA Ames Research Center, as part of a larger research initiative, to investigate the impact on aircraft energy state awareness of the crew. Commercial airline crews flew multiple challenging approach and landing scenarios in a relevant environment. Results show that the additional display features have the potential to significantly improve cautiousness of the flight crew
Nonlinear Femtosecond Pulse Reshaping In Waveguide Arrays
We observe nonlinear pulse reshaping of femtosecond pulses propagating in a waveguide array. The reshaping is due to non-linear coupling between waveguides. The output temporal width shows power-dependent pulse shortening. © 2008 IEEE
Nonlinear Femtosecond Pulse Reshaping In Waveguide Arrays
We observe nonlinear pulse reshaping of femtosecond pulses propagating in a waveguide array. The reshaping is due to non-linear coupling between waveguides. The output temporal width shows power-dependent pulse shortening. © 2008 OSA / CLEO/QELS 2008
Trajectory Prediction and Alerting for Aircraft Mode and Energy State Awareness
This paper describes the implementation and evaluation of technologies that predict and assess the future aircraft energy state and autoflight configuration, and provide appropriate alerting to better inform pilots of the effect of problematic autoflight inputs or conditions. Prediction algorithms are used to extrapolate the current state of the aircraft based on flight management, autopilot and autothrottle system control laws and knowledge of mode transition logic. The resulting predicted trajectory represents the future four-dimensional flight path of the aircraft if the current course of action is continued. Probabilistic methods are used to estimate the trim envelope through high-fidelity model-based computation of attainable equilibrium sets. The corresponding maneuverability limitations of the aircraft are determined through a robust reachability analysis (relative to the trim envelope) through an optimal control formulation. The combination of prediction and assessment technologies are used to trigger timely alerts to avoid loss of control situations. The maneuvering envelope limits are also indicated on the primary flight display, and the predicted trajectory is displayed on navigation and vertical situation displays. The display features and alerts were evaluated in the Advanced Concepts Flight Simulator at NASA Ames Research Center, where commercial airline crews flew multiple problematic approach and landings scenarios to investigate the impact on current and future aircraft energy state awareness. Results show that the display features and alerts have the potential to improve situational awareness of what the automation is doing now and what it will do in the future
Nonlinear Femtosecond Pulse Reshaping In Waveguide Arrays
We observe nonlinear pulse reshaping of femtosecond pulses in a waveguide array owing to coupling between waveguides. Amplified pulses from a mode-locked fiber laser are coupled to an AlGaAs core waveguide array structure. The observed power-dependent pulse reshaping agrees with theory, including shortening of the pulse in the central waveguide. © 2008 Optical Society of America