Amy R. Pritchett

Describing airspace complexity: Airspace response to disturbances

In ongoing efforts to balance air traffic demand and airspace capacity, airspace complexity stands as a fundamental research problem.This paper proposes a newnotion of airspace complexity by capturing howdifficult a given traffic situation is in terms of the control activity required to accommodate disturbances such as the entrance of another aircraft into the airspace. A complexity map is introduced that offers a graphical view of the control activity required to accept a new aircraft as a function of its essential parameters. The proposed method is illustrated with examples related to traffic flow management and dynamic airspace configuration.

Preliminary investigation of wearable computers for task guidance in aircraft inspection

This paper describes a preliminary investigation of how the capabilities of wearable computers may be used to provide task guidance in mobile environments. Specifically, this study examined how the capabilities of wearable computers may be used to aid a user in an inspection task, using as a case study the procedural task of preflight inspection of a general aviation aircraft. Two different configurations of a computer-based, voice-activated task guidance system and the current method of preflight inspection were compared and evaluated. Initial results demonstrate an over reliance on the computer by the pilots and indicate the importance of the user interface design to the performance of the inspectors. The paper concludes with recommendations on promising directions of research.

Development and Evaluation of a Cockpit Decision-Aid for Emergency Trajectory Generation

The application of intelligent cockpit systems is examined to aid air transport pilots at the task of planning and then following a safe four-dimensional trajectory to the runway threshold during emergencies. The design of a proof-of-concept system is described, including the use of embedded fast-time simulation to predict the trajectory dee ned by a series of discrete actions, the models of aircraft and pilot dynamics required by the system, and the pilot interface. Then results of a e ight simulator evaluation with airline pilots are detailed. In 6 of 72 simulator runs, pilots were not able to establish a stable e ight path on localizer and glideslope, suggesting a need for cockpit aids. However, results also suggest that, to be operationally feasible, such an aid must be capable of suggesting safe trajectories to the pilot; an aid that only verie ed plans entered by the pilot was found to have signie cantly detrimental effects on performance and pilot workload. Results also highlight that the trajectories suggested by the aid must capture the context of the emergency; for example, in some emergencies pilots were willing to violate e ight envelope limits to reduce time in e ight, in other emergencies the opposite was found.

A Review and Reappraisal of Task Guidance: Aiding Workers in Procedure Following

Procedures can greatly benefit workers at tasks such as inspection, maintenance, and assembly. Procedures may serve as a guideline for expert workers or they may provide a list of directives to be followed exactly; either way, procedures serve to structure a task, to aid worker memory, and to guarantee consistency and safety. Light, inexpensive electronics may allow for the development of task guidance systems to further help workers by presenting procedures and associated information about the task. This article reviews the current state of knowledge about the development of task guidance systems, and highlights their potential value in a variety of domains. First, the characteristics of procedural tasks are discussed, as a basis for a discussion on the benefits of procedure following that task guidance systems can support, and potential problems in procedure following that task guidance systems can mitigate. Then, current research results in task guidance systems are summarized. Finally, a discussion is...

Hybrid-System Simulation for National Airspace System Safety Analysis

Analysis of large, complex systems requires simulations of hybrid-system dynamics (i.e., dynamics best described by a combination ofcontinuous-time and discrete-event models) and their interactions. To serve as valuable research tools, such simulations must also be computationally efficient, readily modifiable, capable of simulating systems using models of a wide range of fidelity, and easily reconfigurable to simulate parts or all of the system of interest. The development of a simulation architecture meeting these criteria is described. Issues with its development are described conceptually, and its application to safety analysis of the national airspace system is discussed. In particular, an object-oriented approach to hybrid-system simulation is detailed, and computationally efficient methods of updating the simulation are described and compared. New asynchronous with resynchronization methods of timing individual objects are applied in an example, demonstrating a significant improvement in simulation efficiency.

Modeling Human–Automation Function Allocation

The collective taskwork of a team spans the functions required to achieve work goals. Within this context, function allocation is the design decision in which taskwork functions are assigned to all agents in a team, both human and automated. In addition, the allocation of taskwork functions then creates the need for additional teamwork functions to coordinate between agents. In this paper, we identify important requirements for function allocation within teams of human and automated agents. Of note, many important attributes may be observed only within the detailed dynamics of simulation or actual operations, particularly when a function allocation requires tightly coupled interactions. Building on the preceding companion paper’s conceptual review of the requirements of effective function allocation, in this paper we develop a modeling framework that increases the number of aspects of function allocation that can be examined simultaneously through both static analysis and dynamic computational simulations. The taskwork and teamwork of a modern air transport flight deck with a range of function allocations is used as an example throughout, highlighting the range of phenomenon these models can describe. A follow-on companion paper discusses specific metrics of function allocation that can be derived both from such models and from observations in high-fidelity human-in-the-loop simulations or real operations.

Examining air transportation safety issues through agent-based simulation incorporating human performance models

Agent-based simulation may provide an effective method of evaluating safety issues in air traffic control. For example, simulation of human performance models of controllers and pilots, interacting with aircraft avionics systems and with communication, navigation, and surveillance technologies, may assess both the individual behavior of these agents and the overall emergent behavior of the air traffic control system. This paper describes a collaborative effort in developing an agent-based simulation of air traffic control. In order to exercise the capabilities of the proposed approach, a test scenario was developed to investigate the impact of new avionics systems which provide alerts of clear air turbulence (CAT) to flight crews. An agent-based simulation using the Reconfigurable Flight Simulator (RFS) software architecture and its asynchronous timing methods is outlined. Adaptation of the Man-machine Integration Design and Analysis System (MIDAS) human performance model to model the behavior of pilots and air traffic controllers and to interact with RFS is detailed, including description of an algorithm implemented to synchronize the timing between RFS and MIDAS. This paper then discusses the use of agent-based simulation incorporating human performance models as a means to assess safety.

MEASURING THE FIT BETWEEN HUMAN JUDGMENTS AND AUTOMATED ALERTING ALGORITHMS: A STUDY OF COLLISION DETECTION

Methodologies for assessing human judgment in complex domains are important for the design of both displays that inform judgment and automated systems that suggest judgments. This paper uses the n-system lens model to evaluate the impact of displays on human judgment and to explicitly assess the similarity between human judgments and a set of potential judgment algorithms for use in automated systems. First, the need for and concepts underlying judgment analysis are outlined. Then the n-system lens model and its parameters are formally described. This model is then used to examine a previously conducted study of aircraft collision detection that had been analyzed using standard analysis of variance methods. Our analysis found the same main effects as did the earlier analysis. However, n-system lens model analysis was able to provide greater insight into the information relied upon for judgments and the impact of displays on judgment. Additionally, the analysis was able to identify attributes of human judgments that were---and were not---similar to judgments produced by automated systems. Potential applications of this research include automated aid design and operator training.

Testing and implementing cockpit alerting systems

Abstract Alerting systems are being given new technological capabilities that raise novel issues in their interaction with the operator, requiring new methods of testing in order to accurately assess and predict their ultimate impact on operational performance. This paper reviews operational problems with alerting systems, and outlines difficulties in testing them. A range of effects which should be examined during the testing and implementation of alerting systems are detailed, with an emphasis on understanding the total performance of the joint human-alerting system combination. Methods for testing alerting systems beyond the most-common tightly-controller laboratory experiments are detailed, using recent studies as examples.

Requirements for Effective Function Allocation A Critical Review

In this paper, we identify the requirements for effective function allocation within teams of human and automated agents. These functions include all the activities in the team’s environment required to meet collective work goals, that is, taskwork functions. In addition, the allocation of taskwork functions then creates the need for additional teamwork functions to coordinate between agents. Key requirements include that each agent must be capable of each individual function it is allocated and must be capable of its collective set of functions, including teamwork. Of note, many important attributes may be observed only within the detailed dynamics of simulation or actual operations, particularly when a function allocation requires tightly coupled interactions and when teamwork (including human–automation interaction) may support or detract from effective performance. Finally, we note that function allocation is a key design decision that should be made deliberately. By addressing function allocation early in design, before technologies and interfaces are created, key trade-offs can be considered and fundamental concerns with human factors addressed.