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The objectives of this study were to assess the effects of differing formats of forward-looking primary flight display (PFD; electronic attitude-direction indicator, full-color terrain, uniformly brown terrain) on general aviation (GA) pilot recoveries from unknown attitudes and to determine if recovery assistance embodied in the display could be useful. Total recovery times and control reversals were examined as indexes of performance for 40 GA pilots, and the recovery times were subjected to a comparative analysis using both a parametric difference analysis and an equivalence testing technique. Results suggest that for the specific conditions investigated, terrain-depicting PFDs supported performance that was equivalent to that observed with the standard attitude indicator. Equivalence testing is recommended for cases where it is desirable to determine if one device or system provides for performance that is equivalent to another.

Cognitive complexity is a term that appears frequently in air traffic control research literature, yet there is little principled investigation of the potential sources of cognitive complexity. Three distinctly different sources of cognitive complexity are proposed: environmental, organizational, and display. Two experiments were conducted to explore whether these proposed components of complexity could be effectively partitioned, measured, and compared. The findings demonstrate that sources of complexity can be decomposed and measured and furthermore, the use of color in displays, a display design intervention meant to reduce environmental complexity, can actually contribute to it. Language: en

Cockpit displays of traffic information are designed to support pilots' abilities to perform conflict detection and resolution tasks. Three experiments investigated the effects of display dimensionality, conflict geometry, and time pressure of in-flight conflicts on performance. The results indicated that interactive viewpoints in 2 3-D displays eliminated ambiguity costs, resulting in performance on both tasks comparable to a 2-D coplanar display. Viewpoint interactivity in the 3-D displays was vulnerable to increased workload, although corresponding performance was no worse than the 2-D coplanar. All 3 display formats showed performance decrements for nonlevel conflict geometries and increased time pressure. Language: en

One of the most difficult aspects of manually controlled flight is the coupling between the control over the aircraft speed and altitude. These states cannot be changed independent of each other through the aircraft control devices, the elevator and the throttle. Rather, to effectively change an aircraft's speed and altitude, the controls have to be coordinated. The mediating mechanism that underlies the coordination of the controls is the management of the aircraft's energy state. This article shows that the abstraction hierarchy (AH; Rasmussen, 1986) framework can be effectively used to gain more insight into the underlying structure of the aircraft energy management problem. The derived AH representation is based on the analysis of the energy constraints on the control task. It reveals the levels of abstraction necessary to link the aircraft's physical controls to the speed and altitude goals and also how the aircraft energy is a critical mediating state of the control problem. Energy awareness can be ...

In 3 experiments, we examined maneuver choice, flight safety, and mental workload across 3-dimensional (3D) perspective and 2-dimensional coplanar cockpit displays of traffic information in a free-flight simulation. In Experiment 1 (30 pilots), we examined dimensionality issues; in Experiments 2 and 3 (18 pilots each), we examined the effects of traffic density, dimensionality, and vertical profile orientation. Collectively, these data may be modeled by trade-offs between the display types: The coplanar suite suffers from scanning-related integration that increases with conflict density; the 3D display suffers from perceptual ambiguity. This research informs our understanding of how displays modulate performance in free-flight environments.

Visual displays often employ the onset or flashing of an element to notify users of important events. Recent research findings and operational experiences in data-rich, event-driven domains, such as aviation, suggest that this design approach, which was supported by findings from early basic research on attention capture, is not always successful. The goal of this study was to examine how display context affects the effectiveness of abrupt onset signals. Participants in this study performed an externally paced visual task while trying to detect abrupt-onset stimuli, which were presented against 5 different display backgrounds and at 2 different eccentricities. The display background varied in terms of its dynamics and its color similarity to the target. Color similarity, the movement of background elements, and increasing target eccentricity resulted in reduced detection performance. The findings from this study help explain why pilots on modern flight decks sometimes miss changes in the status and behavi...

The retrofit question concerns whether useful and effective synthetic vision displays are usable in aircraft that have limited-size display spaces. Two experiments were conducted to examine the efficacy of these displays and develop field-of-view and terrain texture recommendations for design. The first experiment examined issues of field of view and display size using an Asheville, North Carolina, synthetic vision database and fixed-based simulator. The second experiment was conducted on the NASA B-757 aircraft at Dallas/Fort Worth International Airport and investigated the efficacy of both head-down and head-up displays and generic and photorealistic terrain texture. Both experiments confirmed the retrofit capability and that all sizes and texturing methods were found to be viable candidates for synthetic vision displays. These results, future directions, and implications for meeting national aeronautic safety and capacity goals are discussed.

The aviation community is interested in how use of cockpit displays of traffic information (CDTI) may enable pilots to acquire, identify, verify, and maintain predefined spacing intervals from other aircraft and influence air traffic control (ATC)-pilot communication and workload. In July 1999, as part of an operational evaluation, pilots flew 67 airport traffic patterns (20 CDTI not in use, 47 CDTI in use). Routine ATC procedures were retained. Pilots were trained to augment responses to ATC traffic calls with traffic call signs. An analysis of 1,127 pilot-controller messages revealed CDTI increased collaboration, reduced frequency congestion, resulted in more responsive pilot reports, and increased visual acquisitions. However, 4% of the traffic-related messages contained problems stemming from the call sign procedure. In light of the findings, the call sign procedure is undergoing modification and reevaluation before implementation.

The effectiveness of three different data link interfaces, involving auditory, visual, and redundant presentation of Air Traffic Control (ATC) information, was evaluated in a single pilot general aviation simulator. Fifteen certified flight instructor pilots flew a Frasca flight simulator with full visual display of the outside world, through a series of ATC-instructed maneuvers, while scanning outside for traffic. ATC instructions, of various lengths, were delivered through a text based data link display, through synthesized voice (similar to the current system), or through a redundant voice-text format. Pilots read back the instructions and then complied with whatever maneuver was instructed, while monitoring for traffic. Visual scanning was measured. The results revealed that the visual display provided greatest accuracy of communications readback, and was least disruptive of both traffic monitoring and flight path tracking. The auditory-only condition was most disruptive of these tasks, in part becaus...

Ergavionic principles governing the design and operation of an airplane cockpit were discovered through simulator and flight experiments starting during World War II and continuing through the 1970s, but their systematic application has not happened. These principles deal with control location and operation, display integration and pictorial realism, and control/display direction-of-motion relationships. Systematic application of these principles would make the job of flying an airplane so much easier and safer that hundreds of lives would be saved every year, and in the decades to come, thousands of lives.

This study compared the effect of alternative graphic or numeric vertical navigation aircraft cockpit displays on horizontal and vertical flight technical error, workload, and subjective preference. Displays included (a) a moving map with altitude range arc; (b) the same format, supplemented with a push-to-see profile view, including a vector flight-path predictor; (c) an equivalent numeric display; and (d) a numeric nonvertical navigation display. Sixteen pilots each flew 4 different approaches with each format in a Frasca 242 simulator. Our vertical navigation displays reduced vertical flight technical error by as much as a factor of 2 without increasing workload. Relative advantages of the graphics formats are discussed.

In a variety of domains, automation technology has evolved from passive tools to highly autonomous agents that can initiate actions independent of user input and without explicit operator consent. This evolution brings with it an increased need for effective human-automation communication and coordination to ensure that both agents stay informed about each others' goals, activities, and limitations. Yet, most modern systems are not equipped with the skills required to contribute effectively and in a timely manner to the exchange of information on commitments and actions. In particular, systems fail to provide external attentional guidance to their operators in the case of uncommanded changes and events, which can lead to automation surprises and, sometimes, incidents and accidents. To a large extent, these problems can be explained by designers' increasing reliance on automation feedback that requires focal visual attention. This article explores the potential of multisensory displays to better support at...

A simulation study was performed to evaluate helmet-mounted display symbology for fighter aircraft ground collision avoidance systems. Four visual alert symbologies were tested: an iconic cue, an aircraft-fixed (AF) guidance cue, a head-fixed (HF) guidance cue, and an HF guidance cue with a pitch ladder. Participants were given audio and visual side tasks and responded to alerts in different aircraft attitudes. Shorter reaction times were observed when a HF visual alert was given in addition to the standard audio alert. No significant differences in recovery performance (measured by response time and altitude loss) were observed between display formats. However, the display format had a significant effect on participant head motion. With HF guidance cues, pilots were able to perform the recovery maneuver with their heads off axis; with AF guidance cues or no guidance cues, pilots consistently turned their heads to face forward before maneuvering the aircraft.

Thirty-six participants were tested on their ability to orient toward the nearest airport based on the manner in which information was presented on a global positioning system (GPS) area navigation display. Results indicated that use of the tabular, text-only format normally found on such displays was significantly slower and less accurate than either a map display of nearest airport information or a text display that included an orientation symbol. Additionally, pilots ignored information from the heading indicator, focusing on the GPS to perform the task. Discussion focuses on the need to support pilot decision making.