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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.

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

An operational evaluation of the automatic dependent surveillance system and cockpit display of traffic information (CDTI) provided an opportunity to examine how pilot use of CDTI enabled them to maintain predefined spacing intervals from other aircraft. Seventy percent of the controller -issued traffic calls resulted in positive visual acquisitions (83% displayed on CDTI). Approximately 55% of the approach clearances that included instructions to "follow that traffic" involved communication problems and operational concerns. In light of the findings and the participants' comments, changes to proposed procedures and supporting phraseology will be constructed and evaluated for the approach spacing application.

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.

Synthetic vision information systems (SVIS) are the next generation of cockpit display systems that will become an integral part of the commercial flight deck in the future. The goal of this study was to evaluate SVIS against conventional glass cockpit displays to assess whether or not SVIS can improve pilot performance, situation awareness (SA), and workload. The evaluation was conducted in a fixed-base laboratory flight simulator located in the Operator Performance Laboratory at the University of Iowa. A total of 12 pilot evaluators hand-flew fairly difficult approaches into the Eagle County, Colorado, airport. Specially designed questionnaires were used in various phases of the flights to estimate workload, SA, and user preference. Information relating to SA was collected using the Situation Awareness Global Assessment Technique and workload estimates were obtained using the NASA Task Loading Index technique. Eye movement data were collected using a modified IScan ETL 500 system, and analyzed to find a...

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 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...

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.

Three prototype displays are contrasted for aircraft navigation and tactical hazard awareness: a conventional 2-D coplanar display, an exocentric (God's eye) 3-D display, and an immersed (pilot's eye) 3-D display coupled with a small scale global display. Strengths and weaknesses of each display type are discussed, related particularly to the ambiguity of perspective displays and to attention allocation problems with dual-display suites. In Experiment 1, 8 pilots flew with each of the displays around an airspace populated by waypoints, hazards, and traffic. Performance measures revealed the anticipated costs and benefits of each display type. In Experiment 2, cognitive engineering techniques of performance and cognitive task analysis were applied to remediate the weaknesses of each display type. Emphasis was placed on display enhancements to resolve 3-D ambiguity and visual momentum and cueing techniques to facilitate attention allocation and switching. Analysis of performance of 27 additional participant...

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.