From The Ergoweb® Learning Center

Human Factors Teams Striving to Bring Aviation Technology Under Control

Aviation authorities and the industry have covered great distances since Kitty Hawk, and flying can be described as relatively safe and reliable. A journey through the human factors research projects at the Federal Aviation Administration (FAA) suggests “relatively” is a resilient part of the description. It shows that technology solves problems but introduces challenges at the same pace.


The research findings help shape the guidelines, handbooks, advi­sory circulars, rules and regulations issued by the agency. It covers the development of methods for training and sharpening the performance of air­crews, inspectors and maintenance technicians. Researchers are also investigating way to improve human-centered flight con­trols and displays, and researching considerations in the certification of new aircraft and equipment design and modification.


The FAA human factors web site offers a wealth of information about present and emerging challenges and where researchers are looking for solutions.


One HF project aims to improve aircraft maintenance operations by making Interactive Electronic Technical Manuals (IETMs) more practical. The idea has been around for over two decades, but it didn’t become an attractive option until technology and computing power caught up.


IETMs promise many benefits – some logistical, and some relating to cost. Electronic delivery puts information from a multitude of directions at the fingertips of a maintenance operator, who can access any source easily without having to turn pages sequentially. Updating is simple and central. Being paperless, IETMs don’t involve the expense and nuisance of reprints and inserts or the cost and complications of delivery. More advanced IETMS can provide task-specific diagnosis and procedural guidance, as well as multimedia content.


The work environment, which impacts performance and safety, is also under scrutiny. Flaws lurk in many areas, in the ambience and design of tasks, for instance, or in workstations that don’t accommodate the full range of worker anthropometrics. Tools might be poorly placed, potentially increasing errors and forcing users to adopt uncomfortable or awkward positions that can lead to inefficient processes and musculoskeletal disorders (MSDs). As the impact of flaws isn’t always evident until the workplace is in use, three Operations Control Centers (OCCs) have been set up by the researchers to detect ergonomic issues, devise cost effective strategies that improve workplace and workspace design and help operators perform tasks more safely and efficiently. They are then able to test the measures at the OCCs during actual operations.  


A System Falling Short


The goal of air traffic systems is to move aircraft across the National Airspace System (NAS) in a safe and efficient manner, and one HF project description remarks that present air traffic control systems don’t measure up to the task. It catalogs a list of problems: systems often employ different user interfaces (UIs), even where they serve similar NAS purposes; and information might be presented using different techniques, in different locations or in different data formats. The critique points out that UI issues can reflect real operational differences or technical limitations of the equipment. In many cases the differences are historical, meaning that they vary because they were designed at different times by different programs and vendors. The designs sometimes reflect operational differences or technical limitations that no longer apply.


The FAA is developing the Common Automation Platform (CAP) and Next Generation Air Traffic System (NextGen) to upgrade the air traffic system, creating more challenges for the HF teams. Developers are facing setbacks. The description of the project notes that they are forced to rely on copious but uncoordinated data and standards. As a consequence, they could be unaware of proven UI alternatives and could unknowingly implement UIs that have already been shown to cause human factors problems. At best, not having a standard can lead to unnecessary effort as multiple programs “reinvent the wheel.” At worst, it can lead to perpetuating bad UI designs. It is also noted that many UI guidelines exist, including the FAA Human Factors Design Standard, but none is specific to air traffic control tasks, information or environments.


The analysis concludes that the developers need a single, detailed standard incorporating human factors guidelines and best practices related to ATC systems. The HF researchers are supporting that goal by working towards a uniform standard for all ATC display elements. Present work is directed at determining a color for the standard that provides the best human performance.


Various automation tools are being introduced, along with new display technology, to improve the performance of tasks associated with air traffic control. The aim is to provide decision support for controllers and reduce their task load.


One point of attack is the design and complexity of the display, both of which influence the usability of the tool. If the display is too complex, for instance, it increases the information load for operators. Researchers assigned to the attack point out that studies have focused on perceptual and cognitive UI issues, such as graphical perception, layout appropriateness and interface usability, but that no single effort has completely evaluated an automation interface. They also maintain that most studies have been directed at the way information is displayed, not on its complexity.


The air traffic system adds another complication in that tasks have to be performed in a dynamic and timely manner. The time-demand feature has not received sufficient attention in general research and in some aviation-related assessments of new technologies, according to the researchers. They say assessment methods commonly determine measurements by assuming the system is static or by taking “snapshots” of a dynamic system. The team aims to develop dynamic and timely objective measurements, at the same time identifying factors that contribute to information complexity. These include the number of colors and text font sizes and different display options.


Managing Weather


From the researchers’ description, one Herculean project – it won’t be completed until 2009 – is aimed at reducing weather-related accidents. It involves the development of weather information displays for three domains – pilots in flight, the Terminal Radar Approach Control (TRACON) and the control tower. In current ATC operations, the primary task for controllers is to keep aircraft separated while severe weather avoidance is primarily a responsibility of the pilot. The two missions need to be coordinated. This isn’t simple. The necessary resources are uncoordinated and unevenly distributed, and there are large differences between systems. And some vital weather displays relating to storm fronts and movements are not available to controllers. These are listed by the researchers as the Weather Systems Processor, Corridor Integrated Weather System, Integrated Terminal Weather System and Terminal Doppler Weather Radar.


In each area of specialization the supervisor can tailor the Enhanced Status Information System (ESIS) display to show many types of weather information to controllers. These include weather loops, visibility and ceiling values, predicted thunderstorm movements and icing forecasts. ESIS falls short because it is not specifically tailored for controller weather avoidance and might not be detailed enough for a pilot to make a decision. In short, the researchers say, in current terminal and in flight operations there are no specific weather avoidance displays available for controllers and no procedural requirements.


Their goal is the development of a system that brings together weather information for all three ATC domains and a seamless delivery method for the data. 


The Data Management Headache


HF researchers are also attacking flight data issues, the management of which is a headache for the controllers. Typically they use paper Flight Progress Strips (FPSs) for the purpose, according to the researchers, a practice that compounds the physical and cognitive workload. Controllers must record any changes to flight data by hand while mentally correlating FPS information with the associated aircraft within the area of operations. Because the flight data is not integrated with other sources of information, controllers must constantly shift their visual attention among different sources of flight data and operational information to build their mental picture of the traffic situation.


The strips do not allow controllers to easily record and track flight data or to transfer flight data from one facility to another, another problem.


The goal is to supply flight data to the controllers electronically, seen as a way of reducing the physical and physical cognitive workload, and the researchers are developing prototypes. They see including weather and runway/taxiway information as a useful direction.


A first step towards the right prototype is understanding how controllers use the strips and notepads of today, how often they use them and how they perceive their importance.  


Control Safety Alerts


The FAA is keen to know how and when to present an alert to the controller in order to avert accidents. A recent midair collision and a near miss, as well as 11 accidents where alerts appear to have been missed by controllers, motivated the study. The researchers will be looking for human factors problems in present ATC safety alerts and the frequency and circumstances in which they occur. They plan to write recommendations based on HF research and best practices that will reduce the likelihood or impact of the problems they identify as part of the study. These could involve changes to the automation system user interface, the safety alert logic or algorithms, operational procedures or local implementations.


And the FAA’s is testing an En Route Automation Modernization (ERAM) system to replace the present setup for commands. It is designed to provide a variety of new UI features for accessing and executing controller commands. The most frequent commands will be targeted in the system. The researchers will be involved in evaluating how effectively controllers are able to work with ERAM.


An Emerging Challenge – Preventing Gridlock


The FAA estimates that air traffic in 2016 will increase by 27 percent over 2005 levels, and several HF projects are designed to help the FAA meet these increased demands.


The researchers point out that in the technical operations environment of the future, operators will be struggling to maintain skills on an increasingly diverse and complex set of systems and equipment. And as systems become more reliable – a probability, particularly if the concept of Reliability Centered Maintenance takes root – operators might not work on a particular system more than once a year. The interactive electronic manuals of the future are expect to adapt well to that circumstance, providing on site information for troubleshooting of mission-critical systems.


The FAA is continuing to modernize the National Airspace System to manage the increase in air traffic. One potential direction under investigation is whether pilots can be allowed more responsibility for separating appropriately equipped aircraft from one another without compromising safety or creating more work for controllers. Potentially, aircraft that are self-separating can be treated as a single group by the controller, thus reducing the number of air/ground communications needed and increasing the number of aircraft that can be managed.


In the national system, controllers already manage self-separating military aircraft as a single group when the planes fly in formation. Advanced flight management systems ensure their separation from one another. Expanding the concept to nonmilitary aircraft would require a basic cockpit display of traffic information for the pilot for guidance on maneuvering to maintain the right sequence and spacing.


The benefits of self-separation include a reduction in voice communications, seen as a way to increase a controller’s capacity to handle more aircraft. The difficulty is that grouping could cause an overload of information on the radar display, potentially limiting the number of aircraft a controller can manage and offsetting the gains from a reduction in communication. It promises to be less of a problem if the information can be consolidated so controllers are able to recognize planes that are part of a group. The researchers will be exploring this path with the aid of simulations based on the mix of aircraft projected to be flying in the national system in 2015. They will examine data on aircraft performance, operational errors and losses of separation, efficiency, workload, situation awareness and communications.


Future Terminal Workstation ’07


The modernization of the national system calls for the introduction by 2015 of the Common Automation Platform to replace the Common Automated Radar Terminal System and the Standard Terminal Automation Replacement System. In the meantime, equipment and procedures for the radar approach control, TRACON, will be upgraded to accommodate the increase in traffic volume and complexity. New surveillance, navigation and communication technologies are under development for the TRACON. Many different combinations of technology and procedures are possible. The HR researchers will be investigating how the different systems interact with each other when brought together for use by controllers.


The Next Generation Air Transportation System was developed to identify procedural and technological advancements. One concept under scrutiny is the Virtual Tower, which describes technology to enable controllers to manage traffic at airports physically removed from their location. Rather than a controller providing services by looking out the window of a physical tower located near a given runway, services would be provided for that runway by a controller located miles away, monitoring taxiways and runways on a series of displays.


Virtual tower displays could include camera views of the taxiways, runways and the surrounding environment. By enabling the controller to control traffic remotely, virtual tower positions can be physically located with other virtual towers at consolidated facilities. Consolidation such as this is meant to cut down on facility overhead and help ease staffing concerns.


The researchers will be looking into whether control services can be provided with only a camera view of the runway and its surrounding environment, or whether cameras are needed at all. If cameras are used, developers will need to know what locations on the airport the cameras need to provide visual access to and what capabilities, such as telephoto and panning, that the cameras will need.


For all the benefits technology has delivered and/or promises, it has introduced an equal part of chaos. The analyses and critiques of the researchers suggest coordinating the advances could be a tough part of the journey to safe, rather than relatively safe, flight.


Source: FAA

This article originally appeared in The Ergonomics Report™ on 2007-06-22.