Single Pilot Operations in Domestic Commercial Aviation.

OBJECTIVE: To provide an overview of concepts of operation for single pilot operations (SPO) and a synthesis of recently published work evaluating these concepts. BACKGROUND: Advances in technology have made it possible for a commercial aircraft to be flown by a single pilot under normal conditions, and research is being conducted to examine the feasibility of implementing SPO for commercial aviation. METHOD: Context leading up to the consideration of SPO for commercial flight is provided, including the benefits and challenges. Recent studies examining issues relating to automation, operations, and communications in the SPO context are presented. RESULTS: A number of concepts have been proposed and tested for SPO, and no one concept has been shown to be superior. Single pilots were able to successfully resolve off-nominal scenarios with either the ground-support or cockpit-automation tools examined. However, the technologies developed in support of these concepts are in prototype forms and need further development. CONCLUSION: There have been no obvious "show stoppers" for moving toward SPO. However, the current state of research is in its initial stages, and more research is needed to examine other challenges associated with SPO. Moreover, human factors researchers must continue to be involved in the development of the new tools and technologies to support SPO to ensure their effectiveness. APPLICATION: The research issues highlighted in the context of SPO reflect issues that are associated with the process of reducing crew members or providing remote support of operators and, more generally, human interactions with increasingly autonomous systems.

Evaluating probe techniques and a situated theory of situation awareness.

Probe techniques for measuring situation awareness (SA) vary in whether scenarios are paused and displays visible while questions are presented. We examined which technique is least intrusive on workload and performance in air traffic control, and which is most sensitive at capturing differences in SA when automation varies. We also tested predictions from the situated SA theory, which holds that operators offload specific and low-priority information onto displays to limit internal processing. To accomplish these goals, Experiments 1 and 2 manipulated whether radar displays were visible and scenarios paused during queries. Experiment 2 also manipulated the amount of automation by varying the percentage of aircraft equipped with NextGen tools. We found all probe techniques were equally sensitive at capturing SA differences for different levels of equipage, but those that paused scenarios were least intrusive. Moreover, consistent with situated SA, blanking displays impaired ability to answer questions about specific but not general information. Experiment 3 recorded eye gaze frequency and duration during queries when scenarios were visible and not paused and, as predicted by situated SA, found participants were more likely to look at radar displays while answering specific and low-priority questions than general and high-priority questions. (PsycINFO Database Record

Effects of Music and Tonal Language Experience on Relative Pitch Performance.

We examined the interaction between music and tone language experience as related to relative pitch processing by having participants judge the direction and magnitude of pitch changes in a relative pitch task. Participants' performance on this relative pitch task was assessed using the Cochran-Weiss-Shanteau (CWS) index of expertise, based on a ratio of discrimination over consistency in participants' relative pitch judgments. Testing took place in 2 separate sessions on different days to assess the effects of practice on participants' performance. Participants also completed the Montreal Battery of Evaluation of Amusia (MBEA), an existing measure comprising subtests aimed at evaluating relative pitch processing abilities. Musicians outperformed nonmusicians on both the relative pitch task, as measured by the CWS index, and the MBEA, but tonal language speakers outperformed non-tonal language speakers only on the MBEA. A closer look at the discrimination and consistency component scores of the CWS index revealed that musicians were better at discriminating different pitches and more consistent in their assessments of the direction and magnitude of relative pitch change.

Application of part-whole training methods to evaluate when to introduce NextGen air traffic management tools to students.

The Next Generation Air Transportation System (NextGen) will use advanced technologies and new concepts of operation to accommodate projected increases in air travel over the next few decades. Use of NextGen tools requires air traffic controllers (ATCos) to use different procedures than those required to manage NextGen-unequipped aircraft, and ATCos will need to integrate the 2 skill sets when managing a sector consisting of NextGen-equipped and unequipped aircraft. The goal of the present study was to determine the effectiveness of 2 procedures in the training of student controllers to manage both equipage types. We applied a variant of the part-whole training paradigm in the present study. Using a quasi-experimental design, we trained students from 2 different labs of an internship course to manage air traffic with potential NextGen tools concurrent with their traditional training (whole-task group) or after they had time to learn traditional air traffic management skills (part-whole group). Participants were then tested in their ability to manage a simulated sector consisting of different percentages of NextGen-equipped and unequipped aircraft at the mid-term and after the final week of their internship. Results showed that it is better to train students in manual ATCo skills before introducing NextGen tools, unless the students are of higher aptitude. For more skilled students, simultaneously introducing NextGen and manual tools into their curriculum had little negative impact.

Effects of displacement magnitude and direction of auditory cues on auditory spatial facilitation of visual search.

OBJECTIVE: The objective of this study is to examine the effects of cue error on auditory spatial facilitation (ASF) of visual search. BACKGROUND: ASF is the reduction in time needed to locate and identify a visual target when an auditory cue is presented at the location of the target. Although ASF has been shown to occur when the auditory cue coincides with the target location, it is important to determine whether facilitatory effects are also evident when the cue is displaced. METHOD: Participants performed a visual search task in the presence of an auditory cue that was presented at the center of the screen (uninformative), at the location of the target (accurate), or displaced up to 12 degrees from the target horizontally or vertically. RESULTS: Generally, displaced auditory cues reduced search times as compared with a condition in which the cue was uninformative. When the displacement was always along a single spatial dimension, the cue was as effective as a coincident cue if it was within the local visual area. However, when the dimension along which the cue was displaced varied randomly, the cue did not necessarily reduce search time and hurt performance when the visual search task was difficult. CONCLUSION: Designers of virtual audio displays should be aware that auditory cue accuracy will be affected by the difficulty of the visual task and the operators' knowledge of cue precision and reliability. APPLICATION: Findings from this study can be applied to the design of multimodal interfaces and augmented or virtual environments.

A comparison of auditory and visual apparent motion presented individually and with crossmodal moving distractors.

Unimodal auditory and visual apparent motion (AM) and bimodal audiovisual AM were investigated to determine the effects of crossmodal integration on motion perception and direction-of-motion discrimination in each modality. To determine the optimal stimulus onset asynchrony (SOA) ranges for motion perception and direction discrimination, we initially measured unimodal visual and auditory AMs using one of four durations (50, 100, 200, or 400 ms) and ten SOAs (40-450 ms). In the bimodal conditions, auditory and visual AM were measured in the presence of temporally synchronous, spatially displaced distractors that were either congruent (moving in the same direction) or conflicting (moving in the opposite direction) with respect to target motion. Participants reported whether continuous motion was perceived and its direction. With unimodal auditory and visual AM, motion perception was affected differently by stimulus duration and SOA in the two modalities, while the opposite was observed for direction of motion. In the bimodal audiovisual AM condition, discriminating the direction of motion was affected only in the case of an auditory target. The perceived direction of auditory but not visual AM was reduced to chance levels when the crossmodal distractor direction was conflicting. Conversely, motion perception was unaffected by the distractor direction and, in some cases, the mere presence of a distractor facilitated movement perception.

Concurrent motion detection based on dynamic changes in interaural delay.

The ability to detect a dynamic change in the interaural delay of a pure tone in the presence of a distracter tone of a different frequency was investigated in four conditions: (1) a control condition in which no distracter tone was present, (2) the distracter tone was stationary (fixed interaural delay), (3) the distracter had an interaural delay that changed in the same direction as that of the target tone, i.e., concurrent auditory motion in the same direction, and (4) the distracter had an interaural delay that changed in a direction opposite to that of the target tone, i.e., concurrent auditory motion in opposite directions. In a cued single-interval two-alternative forced-choice design, the observer had to determine if the target tone had a constant or dynamic interaural delay. The target was a 500-Hz tone and the distracter was a tone with a frequency of 300, 510, 550, 600, 800, or 1000 Hz. Detection was also examined for a range of stimulus durations, rates of change in interaural delay (i.e., velocity), and extent of change in interaural time difference (i.e., 'distance'). Results showed that the best performance (highest d') was associated with the no-distracter condition, followed by the stationary-distracter, opposite-direction, and same-direction conditions, respectively. Detection improved with increasing frequency difference between distracter and target tones, but was nonetheless lower than that associated with the no-distracter condition, even when the distracter frequency was several critical bands removed from the target frequency.