Staffed NextGen Tower Human-in-the-Loop 2 (SNT HITL 2): Camera Integration Evaluation

Objective: The purpose of this study is to investigate the effect of a Staffed NextGen Tower (SNT) environment on air traffic control (ATC) operations. The primary objective was to determine whether cameras are beneficial for SNT operations. Background: The SNT concept shifts from relying primarily on the out-the-window view to a model that relies more on using surveillance and cameras. There are different ways to implement the SNT concept. Two alternatives are Supplemental use (in addition to out the window display) and Contingency use (when the out the window view is unavailable). Method: Eight controllers ran traffic in this study with two main conditions, Supplemental and Contingency, with four off-nominal events (aircraft crosses unoccupied runway, aircraft crosses occupied runway, wheels up on approach, aborted takeoff aircraft on runway). Results: The controllers were able to perform their jobs effectively in both Supplemental and Contingency conditions using cameras and surveillance displays. Controllers in conditions with the camera consistently detected the \u2015wheels up on approach\u2016 off-nominal condition. Controllers in conditions without the camera did not detect the \u2015wheels up on approach\u2016 off-nominal condition at all. The other three off-nominal conditions were detected primarily using the Traffic Information Display System (TIDS) and alerts. The controllers rated the camera as essential in both Supplemental and Contingency conditions, although less for Supplemental than Contingency. Controllers agreed that the SNT concept would be beneficial for the National Airspace System (NAS) and for control tower operations. Conclusion: Results of this study show that controllers can perform their jobs effectively in both Supplemental and Contingency SNT environments and show that cameras provide a benefit to operations. Applications: These findings will directly influence decisions on the SNT concept implementation. Although cameras were found to be beneficial, we will still need to refine the details of camera coverage, display configuration, and control functionality. We believe that small improvements based on controller feedback from this study should lead to enhanced situational awareness for controllers and improved ATC performance

Subjective Workload Ratings and Eye Movement Activity Measures

In the present study, we evaluated the possibility of using eye movement activity measures as a correlate of cognitive workload. Using data from a high-fidelity human-in-the-loop weather simulation, we explored eye activity measures like pupil diameter, blink duration, and saccade distance, and assessed their relationship to subjective workload ratings. In our initial analysis, we established that although there was no significant effect of weather tool use on subjective workload ratings, there was a significant relationship between subjective workload ratings and our task load variable aircraft density. We found a linear increase in workload ratings with an increasing number of aircraft in the sector. In a subsequent analysis, we assessed the relationship between eye movement activity measures and aircraft density. We found that the mean blink duration and the mean saccade distance decreased as aircraft density increased, while the mean pupil diameter increased with an increasing number of aircraft in the sector. After establishing the relationship between these eye activity metrics and subjective workload, we evaluated whether we could use changes in eye movement activity along with other system state variables, like distance to weather from the outer marker, to measure ongoing controller workload. We developed both individual controller models and a general model (across controllers) to assess whether it was possible to predict the minute-by-minute number of aircraft in the sector. Using both multiple regression modeling and neural network models, we were able to produce individual controller models and general models with good prediction performances. We discuss possible applications for these findings in future air traffic control (ATC) research, in adaptive automation, and in ATC interface design

Staffed NextGen Tower: A Camera Integration and Computer-Human Interface Part-Task Evaluation

Objective: The purpose of this study was to elicit user feedback and identify computer-human interface issues related to integrating the camera views onto the Staffed NextGen Tower (SNT) displays prior to full human-in-the-loop simulations. Background: Tower controllers in proposed SNT environments will use certified surveillance and camera views instead of the out-the-window view while providing Air Traffic Control services. As the use of cameras for this purpose is a new concept, there are many different ways this concept could be implemented. This study examined some of the alternatives for implementing the SNT concept in a realistic environment. Method: In this study, four NextGen Air Traffic Control Management Cadre members controlled traffic and evaluated camera use during nine 15-minute, low-level traffic scenarios that included off-nominal events. At the end of each scenario and at the end of the study, the participants completed a questionnaire, suggested improvements, and provided comments on adequacy, necessity, and usability of the cameras and displays. Results: The participants suggested making several changes to the camera system prior to future studies. These suggestions included changing the camera placement, increasing the camera resolution, and providing independent cameras for each control position. The participants identified viewing aircraft on final approach and holding short of runways as potential applications for cameras in an SNT environment. Participants also identified the need for some type of alerting decision-support tool. Conclusion: Participants provided specific feedback that can lead to changes in the way the SNT concept is implemented. Applications: Suggested improvements from this study will be incorporated into a future SNT human-in-the-loop simulation and into field demonstrations. The changes identified in this study will guide the future implementation of the SNT concept

Web Based Portal Computer Human Interface Guidelines

This document provides guidance for portal computer-human interfaces. The authors collected information from various standards and guidelines (including the Human Factors Design Standard) and combined it with examples and lessons learned through human factors experience to form specific guidelines. Guidelines within this document are written in the form of should and shall statements. Topics covered include page layout, text design, graphic design, and accessibility standards. Although this document was originally written for a specific portal, most of the guidelines can be applied to websites, intranets, and other web-based applications. This document is meant to be a human factors reference tool used which, when used in conjunction with an experienced human factors professional, can improve the computer-human interface of Federal Aviation Administration portals and web-based applications

Design of Information Display Systems for Air Traffic Control

This document presents standards and guidelines for the design of Information Display Systems for Air Traffic Control (ATC). A computer-based Information Display System (IDS) provides access to various types of information needed to perform a job. The ATC environment and the time critical nature of Air Traffic operations bring unique requirements for an IDS. We developed the standards and guidelines provided here based on existing design guidelines and a study that explored the information and design requirements in the various ATC domains. We conducted structured interviews with 112 ATC Specialists to identify the problems and benefits they experience with IDSs in the field today. We also conducted workshops with Specialists from the field to review and validate our findings. The standards describe the elements that emerged as being critical in the design of an IDS for ATC and the guidelines can be used to effectively implement the standards. We also provide recommendations for human factors activities to support development of IDS design and to evaluate the implementation of the standards

Human Factors Analysis of Safety Alerts in Air Traffic Control

Controllers receive several types of alerts from Air Traffic Control (ATC) automation systems that warn of potentially hazardous situations, including Conflict Alerts, Mode-C Intruder alerts, and Minimum Safe Altitude Warnings. This report provides a human factors analysis of ATC alerts and recommends changes to the alert algorithms and presentation that should increase controller effectiveness and overall system safety. We collected automation data from en route, approach control, and tower facilities that show how often alerts occur, how controllers respond to alerts, and when controller actions occur relative to the alerts. Of all the alerts examined, the majority received no response from controllers; many were so brief that controllers must have resolved the situation prior to the activation or the alert situation resolved itself without action by the controller. Of the alert situations where actions were taken, controllers most often took action before the alert activated. The results suggest that (a) many alerts are valid according to the alert algorithms but do not provide useful information to controllers, (b) these \u201cnuisance alerts\u201d are extremely common in the field, and (c) high nuisance alert rates may desensitize controllers and lead to poor performance. We recommend that the Federal Aviation Administration address the problem of nuisance alerts by improving safety alert algorithms, improving alert presentations, and providing better alert suppression functions. To improve safety alert algorithms, we recommend using data from this study to obtain better measures of critical reaction time parameters for alert algorithms. To reduce the impact of nuisance alerts, we recommend using alert presentations with multiple levels of urgency

Moving Toward An Air Traffic Control Display Standard: Creating A Standardized Target Symbology for Terminal Situation Displays

In this study, we applied human factors best practices to the design of an enhanced target symbol set for terminal displays. To design new symbols, we first identified types of information that would be most operationally useful. We selected four types of information that would provide the greatest operational benefits and tactical support for the controllers. These included aircraft category (Small, Large, Heavy, and Super Heavy), aircraft heading, aircraft altitude, and aircraft conformance to its assigned route or altitude. To evaluate the effectiveness of the symbols, we used search, sorting, and selection tasks that measured symbol preference, reaction time, and symbol identification. Our results indicated that the controllers used consistent heuristics for categorizing symbols into different size and conformance categories. For both the heading and category coding, we also found benefits in terms of both increased accuracy and decreased reaction times. We did not find any benefits for the altitude coding. By using meaningful symbols to convey relevant tactical information, such as aircraft category and heading, we can both increase visual search speed and increase target detection accuracy. On the basis of our findings, we propose a set of symbols and provide recommendations for creating standardized symbology for terminal situation displays and other safety critical systems

Voice Over internet Protocol : Speech Intelligibility Assessment

In this study, we examined the speech intelligibility of five codecs and parameter settings to determine their suitability for Air Traffic Control use. These codecs (g711r64, g726r32, g729r8, g723r53, and g726r16) convert analog communications to digital communications. We used standard intelligibility tests 12 the Modified Rhyme Test (MRT) and the Message Completion Task (MCT) 12 to examine intelligibility differences. For the MRT, codec type had an effect on intelligibility. Performance in an uncompressed audio condition was the best, followed by codecs g711r64 and g726r32, then g729r8, and then g723r53 and g726r16,respectively. Reaction times were consistent with the performance data, with the better performing codecs having shorter reaction times. Subjective intelligibility and acceptability ratings matched the performance and reaction time data. For the MCT, the intelligibility and acceptability ratings for all codecs were high, but we found no clear pattern in the performance data. We recommend that the National Airspace System Voice Switch (NVS) program further evaluate the three best performing codecs,g711r64, g726r32, and g729r8. These codecs delivered the best performance, the shortest reaction times, and the most positive feedback. We also recommend that the NVS Program Office investigate the effect of channel noise, ambient noise, and level of network utilization on the intelligibility of different code

Collocation of User Request Evaluation Tool, Traffic Management Advisor, and Controller Pilot Data Link Communications: An initial Human Factors Evaluation

This study was a human factors evaluation of collocating User Request Evaluation Tool (URET), Core Capability Limited Deployment, Traffic Management Advisor, and Controller Pilot Data Link Communications (CPDLC), formerly Build 1A. Human Factors Specialists conducted the evaluation in two phases: a \u201cpaper and pencil\u201d study - Phase 1 and a modified cognitive walkthrough - Phase 2. They examined the tools from existing documentation and system design in the context of human factors best practices. Four primary human factors issues emerged from this analysis: 1) Computer-Human Interface (CHI) inconsistencies; 2) Radar Associate (RA)-side collocation and timely access to information; 3) Communication of information between the RA-side and Radar-side controllers; and 4) National Airspace System updates from the different tools. Results include recommendations for human factors engineering for integrating the URET, CPDLC, and Computer Readout Display information on the RA-side, as well as working toward improving CHI consistencies