An Attentive Blank Stare Under Simulator-induced Spatial Disorientation Events

OBJECTIVE

This study investigated the effect of the spatial disorientation (SD) events on an attentive blank stare in the cockpit scene and demonstrated how much the flight task and visual delayed discrimination task were competing for the pilots' attention.

BACKGROUND

SD in flight is the leading cause of human error-related aircraft accidents in the military, general and commercial aviation, and has been an unsolved problem since the inception of flight. In-flight safety research, visually scanning cockpit instruments, and detecting changes are critical countermeasures against SD.

METHOD

Thirty male military pilots were performing a dual task involving piloting a flight simulator and visual change detection, while eye movements were obtained using an eye tracker.

RESULTS

Pilots made more flight errors and spent less time gazing at the area of change in SD-conflict than in non-conflict flights. The vestibular origin SD-conflict led not only to deteriorated piloting and visual scanning but also to problems coordinating overt and covert attention, resulting in lower noticeability of visual changes despite gazing at them.

CONCLUSION

Our study shows that looking at a given area in space is not a sufficient condition for effective covert attention allocation and the correct response to a visual stimulus. It seems to be important to make pilots aware of this during SD training.

APPLICATION

To reduce change blindness, some strategies, such as reducing the number of secondary tasks is extremely valuable. Particular efforts should also be focused on improving the design of the aircraft cockpit by increasing the conspicuousness of critical information.

Compatibility effects with touchless gestures

Human actions are suspect to various compatibility phenomena. For example, responding is faster to the side where a stimulus appears than to the opposite side, referred to as stimulus-response (S-R) compatibility. This is even true, if the response is given to a different stimulus feature, while location itself is irrelevant (Simon compatibility). In addition, responses typically produce perceivable effects on the environment. If they do so in a predictable way, responses are faster if they produce a (e.g., spatially) compatible effect on the same side than on the other side. That it, a left response is produced faster if it results predictably in a left effect than in a right effect. This effect is called response-effect (R-E) compatibility. Finally, compatibility could also exist between stimuli and the effects, which is accordingly called stimulus-effect (S-E) compatibility. Such compatibility phenomena are also relevant for applied purposes, be it in laparoscopic surgery or aviation. The present study investigates Simon and R-E compatibility for touchless gesture interactions. In line with a recent study, no effect of R-E compatibility was observed, yet irrelevant stimulus location yielded a large Simon effect. Touchless gestures thus seem to behave differently with regard to compatibility phenomena than interactions via (other) tools such as levers.

Leans Illusion in Hexapod Simulator Facilitates Erroneous Responses to Artificial Horizon in Airline Pilots

OBJECTIVE

We tested whether a procedure in a hexapod simulator can cause incorrect assumptions of the bank angle (i.e., the "leans") in airline pilots as well as incorrect interpretations of the attitude indicator (AI).

BACKGROUND

The effect of the leans on interpretation errors has previously been demonstrated in nonpilots. In-flight, incorrect assumptions can arise due to misleading roll cues (spatial disorientation).

METHOD

Pilots (n = 18) performed 36 runs, in which they were asked to roll to wings level using only the AI. They received roll cues before the AI was shown, which matched with the AI bank angle direction in most runs, but which were toward the opposite direction in a leans-opposite condition (four runs). In a baseline condition (four runs), they received no roll cues. To test whether pilots responded to the AI, the AI sometimes showed wings level following roll cues in a leans-level condition (four runs).

RESULTS

Overall, pilots made significantly more errors in the leans-opposite (19.4%) compared to the baseline (6.9%) or leans-level condition (0.0%). There was a pronounced learning effect in the leans-opposite condition, as 38.9% of pilots made an error in the first exposure to this condition. Experience (i.e., flight hours) had no significant effects.

CONCLUSION

The leans procedure was effective in inducing AI misinterpretations and control input errors in pilots.

APPLICATION

The procedure can be used in spatial disorientation demonstrations. The results underline the importance of unambiguous displays that should be able to quickly correct incorrect assumptions due to spatial disorientation.

Expectation Causes Misperception of the Attitude Indicator in Nonpilots: A Fixed-Base Simulator Experiment

Previous studies show that pilots sometimes make roll reversal errors (RREs) when responding to the aircraft bank angle shown on the attitude indicator (AI). This is suggestive of a perceptual ambiguity in the AI. In the current study, we investigated whether expectation contributes to such misperception. Twenty nonpilots performed tasks in a fixed-base flight simulator. Their expectation about the bank angle was manipulated with a flying task using outside view only. When flying at a bank angle, the outside view disappeared, a moving-horizon type AI was shown, and participants had to roll the wings level, trusting the AI. The AI often matched the previously flown turn. However, in some runs, it showed an opposite bank direction (Opposite condition), which was hypothesized to facilitate a misperception. In some other runs, it showed level flight (Level condition), which should not facilitate this. In a second session, participants rolled wings level without preceding flying task (Baseline condition). Participants made 11.2 times more RREs in the Opposite condition (75% error rate) compared to Baseline condition (6.7%), and 2.5 times more compared to the Level condition (30%). This indicates that RREs were in many cases caused by expectation-induced misperception of the AI bank angle.

In-flight spatial disorientation induces roll reversal errors when using the attitude indicator

We hypothesized that an incorrect expectation due to spatial disorientation may induce roll reversal errors. To test this, an in-flight experiment was performed, in which forty non-pilots rolled wings level after receiving motion cues. A No-leans condition (subthreshold motion to a bank angle) was included, as well as a Leans-opposite condition (leans cues, opposite to the bank angle) and a Leans-level condition (leans cues, but level flight). The presence of leans cues led to an increase of the roll reversal error (RRE) rate by a factor of 2.6. There was no significant difference between the Leans-opposite and Leans-level condition. This suggests that the expectation strongly affects the occurrence of an RRE, and that people tend to base their responses on motion cues instead of on information on the AI. We conclude that expectation and spatial disorientation have a large effect on piloting errors and may cause hazardous aircraft upsets.

Dealing With Unexpected Events on the Flight Deck: A Conceptual Model of Startle and Surprise

OBJECTIVE

A conceptual model is proposed in order to explain pilot performance in surprising and startling situations.

BACKGROUND

Today's debate around loss of control following in-flight events and the implementation of upset prevention and recovery training has highlighted the importance of pilots' ability to deal with unexpected events. Unexpected events, such as technical malfunctions or automation surprises, potentially induce a "startle factor" that may significantly impair performance.

METHOD

Literature on surprise, startle, resilience, and decision making is reviewed, and findings are combined into a conceptual model. A number of recent flight incident and accident cases are then used to illustrate elements of the model.

RESULTS

Pilot perception and actions are conceptualized as being guided by "frames," or mental knowledge structures that were previously learned. Performance issues in unexpected situations can often be traced back to insufficient adaptation of one's frame to the situation. It is argued that such sensemaking or reframing processes are especially vulnerable to issues caused by startle or acute stress.

CONCLUSION

Interventions should focus on (a) increasing the supply and quality of pilot frames (e.g., though practicing a variety of situations), (b) increasing pilot reframing skills (e.g., through the use of unpredictability in training scenarios), and (c) improving pilot metacognitive skills, so that inappropriate automatic responses to startle and surprise can be avoided.

APPLICATION

The model can be used to explain pilot behavior in accident cases, to design experiments and training simulations, to teach pilots metacognitive skills, and to identify intervention methods.

Die Rolle von Handlungszielen bei der Entstehung von Doppelaufgabenkosten

Zusammenfassung. Mehrere Dinge gleichzeitig zu tun, funktioniert oft nicht ohne Leistungseinbußen. Solche Probleme und deren Ursachen werden im Rahmen der Multitasking-Forschung untersucht. Der vorliegende Artikel thematisiert, inwiefern den Zielen von Handlungen bei der Entstehung solcher Leistungseinbußen eine kritische Rolle zukommt. Handlungsziele in Form sensorisch wahrnehmbarer Umweltveränderungen („Handlungseffekte“) spielen in der Ideomotorischen Theorie der Handlungssteuerung eine wichtige Rolle, da ihre Antizipation als der Prozess der Handlungsauswahl gesehen wird. Nach einer kurzen Zusammenfassung der wichtigsten Evidenz für diese Annahme, werden Studien berichtet, die (a) dafür sprechen, dass keinerlei Leistungseinbußen entstehen, wenn eine motorische Bewegung nicht Teil einer Handlung ist, und (b) dass Handlungsziele das Ausmaß der Doppelaufgaben-Probleme bedeutend (mit–)bestimmen. Abschließend wird auf dieser Grundlage die Frage diskutiert, ob es mehrere Arten von Handlungen gibt, wie es verschiedentlich vorgeschlagen wurde. Zusammenfassend weisen die Befunde auf die wichtige Rolle von Zielen sowohl als mentale Vorläufer einer Körperbewegung im Rahmen von Handlungen, als auch bei der Entstehung von Problemen in Multitasking-Situationen hin.

Situation Awareness and Workload in Aviation

A pilot faces special challenges imposed by the need to control a multivariate lagged system in a heterogeneous multitask environment. The time lags between critical variables require prediction in an uncertain world. The interrelated concepts of situation awareness and workload are central to aviation psychology. Three components of situation awareness are spatial awareness, system awareness, and task awareness. Each of these components has real–world implications, spatial awareness for instrument displays, system awareness for keeping the operator informed about actions that have been taken by automated systems, and task awareness for attention and task management. Task management is directly related to mental workload, as the competing demands of tasks for attention exceed the operator's limited resources.

A tactile cockpit instrument supports the control of self-motion during spatial disorientation

OBJECTIVE

We investigated the effectiveness of a tactile torso display as a countermeasure to spatial disorientation (SD) and compared inside-out and outside-in codings.

BACKGROUND

SD is a serious threat to military as well as civilian pilots and aircraft. Considerable effort has been put into SD countermeasures such as training programs and advanced cockpit displays. Tactile displays have been considered a promising technology.

METHOD

Twenty-four participants were assigned to the two coding groups (12 per group and matched for age and gender). We used a rotating chair to build up a state of SD by rotating participants around their yaw axis followed by a sudden stop. During the following recovery phase a random disturbance signal was added to the chair's orientation. Participants actively controlled their orientation and were instructed to maintain a stable orientation.

RESULTS

Statistical analyses revealed that recovery from SD was improved with support of the tactile instrument, but tracking performance was reduced. The effects were the same whether the instrument was available full time or during the recovery phase only. There were no differences between outside-in and inside-out coding.

CONCLUSION

The present study demonstrates the potential of tactile cockpit instruments in controlling SD, even in the presence of strong but misleading self-motion information from the vestibular sense.

APPLICATION

Actual or potential applications of this research include spatial disorientation countermeasures for pilots, divers, and astronauts.

Effects of visual flow display of flight maneuvers on perceived spatial orientation

Postural responses were utilized as measures of the effectiveness of a wide-angle visual flow display in determining perceived spatial orientation (SO). The general experimental setup included a 150 degrees x 34 degrees wide-field display showing flight over computer-generated ground with horizon. Simulated roll maneuvers on this display induced postural sway in the observer that was registered by a head-tracker system. Two experiments with 16 participants in each investigated the effects of visual flow, display exclusions in the central visual field, and display extensions into the visual periphery. Clear vestibular and proprioceptive suppression effects were demonstrated on postural sway with the inclusion of visual flow of forward ego motion in roll maneuvers. Compared with the full view, up to 20 degrees x 20 degrees central field omission either did not reduce the effect or reduced the effect but, frequently, only moderately. Limiting the display area to 45 degrees in the horizontal dimension reduced display effectiveness significantly, whereas a 105 degrees area did not, compared with the full view. Utilizing postural responses as indications of visual display resonance with our SO mechanism, actual or potential applications of this research include the design of an interface integrating flight-adapted visual flow to counteract or reduce pilot spatial disorientation.