Startle and surprise can impair pilot performance and affect flight safety. This study investigates the prevalence of different startle and surprise events among helicopter pilots, its impact on pilot stress and mental effort and the influence of training background. It also looks at currently used startle mitigation strategies and evaluates the usability of a previously proposed “Aviate, Breathe, Check (ABC)” startle management method (Piras et al. 2023). A survey among 234 helicopter pilots revealed that 96% had experienced impactful startle or surprise events during operations. Scenarios such as disorientation, tail rotor incidents, and flight into instrument meteorological conditions (IMC) were considered particularly stressful. Reported levels of stress and mental effort during startle and surprise events did not differ between pilots with higher and lower experience levels or between pilots with a different training background (military or civilian). Only 38% of pilots indicated they were specifically trained to deal with startle and surprise and only 1% were trained to use a breathing technique. Most pilots (90%) expressed openness to implementing the ABC method and expected benefits from using it. Concerns regarding time constraints in critical situations emerged as the primary objection to adopting this technique. Overall, the findings indicate that the introduction of a startle management method tailored for helicopter operations could significantly enhance safety, especially given the higher accident rates compared to fixed-wing operations. Future research should focus on developing effective training protocols that account for the unique challenges of helicopter flying.

Literature on transfer of training largely deals with positive transfer. Only few studies exist on negative transfer, and these were often performed in (laboratory) environments with low ecological validity. This study's objective is to identify factors that contribute to negative transfer in safety-critical professions. The primary focus of the study is on aviation, but investigated principles also apply to other domains with high-performing professionals. Semi-structured interviews were performed with training experts from commercial and military aviation (n = 8), as well as the medical (n = 1) and maritime (n = 1) domain. The experts were asked to list examples of negative transfer that they have observed or experienced themselves. Follow-up questions addressed training approaches and solutions regarding these examples. Answers were categorized using a transfer framework. The experts' most salient concerns involved: Time pressure, which leads to rushed training; Instructors with insufficient understanding of the limitations of the (simulator) training; and the way in which trainees should be placed into hazardous situations in a realistic manner. The experts provided several factors and recalls of experiences which may lead to negative transfer. These results may be relevant for instructors and can provide input for further experimental research regarding negative transfer.

This paper outlines the three-phase construction of the Startle and Surprise Inventories (Startle-I; Surprise-I) and Visual Analogue Scales for Startle and Surprise (Startle-VAS; Surprise-VAS). In Phase 1, seven experts in the field assessed the content validity of 14 items for surprise, 7 items for startle derived from fundamental and applied literature. Elimination of items was based on a 50% agreement of relevance. In Phase 2, 81 participants completed the retained 19 items nine times, each time immediately after watching a video clip. A multilevel exploratory factor analysis was applied to assess the construct validity of items. In Phase 3, concurrent validity of the Startle-VAS and Surprise-VAS was tested by comparing with the Startle-I and Surprise-I scores, respectively. The first two phases yielded a 11-item two-factor solution, corresponding to the constructs of startle and surprise. These results supported Startle-I and Surprise-I as measures of self-report startle and surprise, with Startle-VAS and Surprise-VAS as efficient alternatives.

Introduction: Maintaining cognitive performance during sleep deprivation is of vital importance in many professions, especially in high-risk professions like the military. It has long been known that sleep deprivation diminishes cognitive performance. To mitigate the negative effects on cognitive performance during crucial military tasks, new interventions are necessary. Non-invasive cervical transcutaneous vagus nerve stimulation (ctVNS) has gained traction as a method to boost alertness and cognitive functioning. Methods: We investigated the effects of a 2 × 2 minute ctVNS stimulation protocol on three cognitive tasks applied during conditions of sleep-deprivation: a psychomotor vigilance task (PVT), a multitasking task (SynWin), and an inhibitory control task (stop-signal task; SST). In addition, participants also performed a close-quarter-battle (CQB) test in virtual reality (VR) to examine if potential effects of ctVNS translate to operational military contexts. A total of 35 military operators from Special Operations Forces (SOF) and SOF support units participated. They were randomly assigned to an active stimulation group or sham group. Before stimulation at 19:00 h, participants performed baseline tests. Participants stayed awake through the night and performed the cognitive tasks every 3 h. The last round of cognitive tasks was followed by the VR test. Results: Though sleep deprivation was successfully induced, as evident from a decline in performance on all three cognitive tasks (effect of session: p < 0.001 SynWin; p < 0.001 PVT; p < 0.001 SST; Linear Mixed Model), no significant effects of ctVNS were found on cognitive task performance, as well as on the military operational VR task. However, the influence of stimulation intensity on SynWin performance showed a trend, indicating that higher stimulation intensities could have a negative impact on cognitive performance. Discussion: A 2 × 2 minute stimulation protocol may not be sufficient to elicit beneficial effects on cognitive-and operational military performance. Moreover, correct stimulation intensity may be critical to induce effects on cognitive performance, as stimulation effects may follow an inverted-u dose-response curve. Stimulation intensities in the current study are higher compared to a similar study that reported beneficial effects of ctVNS, which may explain this null finding. Further research is recommended to optimize stimulation protocols and investigate robustness of effects.

We investigated the effect of personality traits and flight experience on pilot cognitive and affective responses across seven startling and surprising scenarios performed in motion-based simulators. A dataset of 89 airline pilots from four studies was used. The personality traits measured were trait anxiety, decision-related action orientation (AOD), and failure-related action orientation (AOF). Pilot self-reported responses in scenarios were standardized by obtaining z scores of startle, surprise, stress, and mental workload. Only trait anxiety was found to be significantly positively correlated with stress. No significant effects of AOD, AOF, or flight hours were found on pilots’ responses. The results indicate trait anxiety may affect pilots’ responses to stressful scenarios, even though pilots are selected based on low trait anxiety.

A significant safety challenge airline pilots contend with is the possibility of experiencing startle and surprise. These are cognitive-emotional responses that may temporarily impair performance and that have contributed to multiple fatal loss of control events. Several self-management methods exist that are intended to facilitate recovery from startle and surprise, but these have only been tested in simulator experiments. The current study addresses this research gap by surveying the perceptions of 239 airline pilots on the utility and benefit of a method which they use in operational practice– the “Reset Method”. Overall, the survey results revealed that pilots felt the method improved mental preparedness, and reduced stress. A reported reason for not applying the method was the urge to act quickly. In addition, not all steps of the method were applied equally, and some pilots found the method difficult to fit into the existing procedures of several time-critical scenarios (e.g., aircraft upsets and emergency landings). We recommend training self-management methods in scenarios which carry the most risk of negative effects of startle and surprise. We also recommend instilling awareness of the ‘startle paradox': self-management techniques are most difficult to apply in situations where they are most beneficial. Method shortening and simplification may facilitate application. Future research should focus on refining the method's implementation, addressing the startle paradox, and understanding the transferability of startle and surprise management methods to other safety critical industries defined by complex sociotechnical interactions.

This manual provides guidance for human factors researchers and applied psychologists, on the standardized and scientifically rigorous use of the instruments. It is structured to include an overview of the instruments, administration guidelines, and a summary of their psychometric properties to support accurate application and interpretation in research and operational contexts.

Pilots frequently encounter startle and/or surprise (S&S), which can negatively affect their performance. To investigate the types of non-nominal events that prompt S&S, 92 pilots from different fixed-wing operating backgrounds - commercial, military and general aviation - completed a survey. In addition to exploring the relative prevalence of different S&S events, the survey required participants to reflect on the level of stress and mental workload experienced during these events. They also rated the perceived effectiveness of any S&S management methods or techniques they may have implemented. Overall, 95% of the participants reported that they had experienced S&S events. Spatial disorientation and bird strikes caused the highest levels of stress. Aircraft system malfunctions, severe turbulence and automation surprises induced the highest workload. The respondents indicated that applying S&S management techniques helped relieve stress and mental workload. The perceived effectiveness of applying breathing-based techniques was significantly greater than other methods. However, despite regulatory recommendations, only 23% of participants were trained in breathing-based methods. The survey also asked participants to remark on their openness to adopt methods that are specifically tailored to expedite emotional and cognitive recovery from S&S. In this study, the Aviate-Breathe-Communicate (ABC) method was evaluated. Across a range of hypothetical S&S events, participants rated the ABC method as most useful in disorientation scenarios. The lack of time was perceived as the most significant barrier to applying this method in critical events. Additionally, participants rated the variability and unpredictability of their training; however, no significant relationship was found between these ratings and perceived stress levels during S&S events. These findings highlighted the need for improvement in S&S training programs and emphasised the recommendation of breathing-based techniques for managing acute stress in high-stakes situations.

We tested whether pilots would detect low-salient controllability problems more quickly during manual compared to automated flight. Using a moving-base simulator and a Piper Seneca aerodynamic model, airline pilots (n = 20) performed scenarios in which either a gradually ensuing single-engine failure or an icing accumulation occurred. Both scenarios were performed once during manual flight and once during automated flight, and were alternated with distraction scenarios. The icing accumulation was detected marginally significantly more quickly during manual flight, while there was no significant difference for the engine failure. Problems in manual flight were, as expected, most likely discovered from aircraft motions or control forces. Interestingly, there were several late detections during manual flight which appeared to be caused by subconscious manual corrections. In automated flight, the engine failure was discovered most often from the engine manifold pressure indication, while the icing accumulation was most often discovered from control column movement. The results therefore underline the importance of using back-driven controls, and further indicate that manual flight does not necessarily improve detection of problems that occur without display indications.

Previous studies have indicated that the attitude director indicator (ADI) used in commercial aviation is suboptimal in representing the bank angle direction, which can lead to confusion, roll reversal errors and increased workload. Confusion about the bank angle direction has been implied in several cases of loss of control in-flight (LOC-I). In the current study, we therefore tested whether bank angle representation can be improved by adding non-disruptive visual depth cues to the ADI. An enhanced ADI was created, in which three monocular cues were added: atmospheric haze (i.e. a gradient in color towards the horizon), a shadow line under the aircraft symbol, and perspective lines on the ground. Airline pilots (n = 25) were tasked with rolling back to level 96 times from unforeseen (30 or -30 degrees) bank angles after experiencing either matching or mismatching (disorienting) roll motion cues in a motion-base simulator. There was no outside visibility and pilots responded using the ADI only. Roll reversal errors and reaction times were compared within-subject between the enhanced and baseline ADI, which were both based on the B747. Pilots were tasked to respond immediately upon presentation of the display, so that their initial interpretation of bank angle direction could be measured. There was no significant difference in roll reversal errors, and a significant increase in reaction times, when using the enhanced ADI compared to the baseline ADI. This suggests that pilots had slightly more difficulty with reading the bank angle with the enhanced ADI. Of the pilots, 56% preferred the enhanced ADI over the baseline display as it is, 8% had no preference and 36% preferred the baseline ADI. The most valued addition was the perspective lines on the ground, which pilots remarked would also be helpful in recovering extreme attitudes. The most-heard concerns were about potential clutter caused by the added cues, and difficulty with accurate reading of the pitch angle due to the shadow lines. In conclusion, according to the pilots' feedback, the addition of depth cues to the ADI appears promising, but it should be tested using more challenging tasks. Further design changes also appear needed to prevent clutter and facilitate quick reading of the aircraft attitude.

Data from two simulator experiments were examined to investigate whether performing an auditory task influences pilots' gaze behaviour. Gaze behaviour was measured while participants performed a manual flying task with an auditory task (dual-task condition) or without (single-task condition). Experiment 1 took place in a fixed-base, fixed-wing simulator with 15 novice military pilots. Experiment 2 took place in a moving-base, rotary-wing simulator with 13 experienced military helicopter pilots. Percentage dwell time outside significantly increased in the dual-task condition compared to the single-task condition in both experiments, by a factor of 1.2 and 1.5 respectively. Mean duration of fixations outside significantly increased for pilots, while it decreased for novices. In novices, altitude control performance was also significantly reduced when performing the auditory task, whereas bank angle control performance significantly increased in experienced pilots. The impact on gaze behaviour may potentially serve as a behavioural indicator of pilot auditory workload.

Startle and surprise can impair pilot performance and jeopardize flight safety. Self-management methods have been developed by the industry to address this acute source of stress, however, qualitative insights from pilots describing the quality of these methods are lacking. Ten semi-structured interviews with airline pilots, who had been taught a self-management method, were analyzed using thematic analysis). Pilots considered the method useful and reported positive effects (e.g., decrease in stress) when applying the method during operations. Pilots reported that the method was not often performed in full; specific steps were employed based on perceived benefit. Establishing fellow pilot status and situation awareness was considered most important, addressing own physical startle symptoms (e.g., muscle tension) were deemed less important. Pilots reported an urge to “act” rather than use the method, which is expected as the method aims to induce a pause and mitigate erroneous impulsi ve decisions. Barriers to applying the method included the difficult recognition of startle and surprise, and situational context. Suggested improvements for training dealt with recognition and sharing experiences from peers. The findings of the research provide directions for pilot training for startle and surprise. Future research will explore these pilot perceptions in a larger representative sample.

Automation errors may result in human performance issues that are often difficult to grasp. Skraaning and Jamieson (2023) proposed a taxonomy for classifying automation errors into categories based on the visible symptoms of design problems, so as to benefit the design of training scenarios. In this paper, we propose a complementary classification that is based on the mechanisms of human-automation interaction guided by Rasmussen’s Skill, Rule and Knowledge (SRK) taxonomy. We identified four main failure classes and expect that this classification can support automation designers.

Previous research indicated a need to improve pilot training with regard to understanding of autopilot logic and behavior, especially in non-routine situations. Therefore, we tested the effect of problem-based exploratory training on pilots’ understanding of autopilot functions. Using a moving-base flight simulator, general aviation pilots (n = 45) were trained to diagnose failures either without foreknowledge and guidance (exploratory group), without foreknowledge but with some guidance (exploratory-guidance group) or with foreknowledge and full guidance (control group). They subsequently performed six test scenarios in which their understanding of the effects of failures was tested by requiring them to deduce the failures and select autopilot modes that were still functioning. Those who received exploratory training with guidance were significantly more likely than the other groups to diagnose failures correctly. The exploratory training group also selected the most appropriate functioning autopilot modes significantly faster than the control group. The results suggest that exploratory training with an appropriate level of guidance is useful for gaining a practical understanding of autopilot logic and behavior. Exploratory training may help to improve transfer of training to operational practice, and prevent automation surprises and accidents.

Objective
We aimed to find objective measures of the impact of spatially disorienting (SD) stimuli on pilot cognition in an ecologically valid environment.
Background
SD frequently occurs in military rotary-wing operations and often contributes to mishaps. Effects of SD stimuli on pilots are usually quantified using control errors, but effects on cognition have not yet been successfully quantified.
Method
Military helicopter pilots (n = 14) performed scenarios with six SD stimuli (SD condition) and six corresponding control stimuli (NoSD condition) in a motion-base simulator with integrated virtual reality headset. SD stimuli were: false horizon, featureless terrain, leans, brownout, a somatogyral yaw illusion, and loss of horizon due to night vision goggles (NVGs). Mental workload was measured using auditory arithmetic task performance and attentional focus was measured using eye-tracking.
Results
Average arithmetic task performance was significantly impaired, and proportional gaze dwell time on the attitude indicator was significantly increased in the SD compared to the NoSD condition. Of the six SD stimuli, the featureless terrain, the leans, and the brownout induced significant effects on performance, whereas the featureless terrain, brownout, and false horizon significantly affected gaze behavior. The NVGs and somatogyral yaw stimuli did not induce significant effects. Pilots’ self-reports indicated awareness of all SD stimuli, except for the featureless terrain.
Conclusion
The results indicate that SD impacts pilot mental workload and attentional focus.
Application
Modern military aircraft present a large volume of mission-related information to pilots. This study shows that SD stimuli may negatively impact the processing of such information.

We investigated whether deliberately going beyond alarms during aerodynamic stall recovery exercises may result in negative training. Two groups of 20 airline pilots received stall recovery training in a moving-base simulator. The “delayed-response” group induced the stall themselves. The “immediate-response” group was presented with paused situations and had to recover immediately after unpausing. In a surprising transfer test, the pilots in the delayed-response group showed less aggressive unloading, and experienced significantly more time pressure compared to the pilots in the immediate-response group. In a stall cue recognition test, the delayed-response group performed nearly significantly better. We conclude that experiencing the progression of an aerodynamic stall during training has positive effects on pilot performance, even if this requires unprocedural behavior.

Background. Previous studies and accident analyses have shown that pilots can make roll reversal errors when responding to bank angles shown by the artificial horizon in the Primary Flight Display (PFD). In the current study, we tested whether adding stereoscopic depth cues to the artificial horizon may lead to better bank angle representation due to an improved figureground separation between the symbols. Method. Stereoscopic depth cues were created by using a half-silvered mirror multi-layer PFD, which presented the horizon symbol on a lower layer and the aircraft symbol on a higher layer. A group of 23 non-pilots and 18 general aviation pilots were shown left or right bank angles on this multi-layer PFD as well as on a normal single-layer PFD, with the task to roll the wings level using a joystick. Results. In the pilot group, a similar amount of roll-reversal errors was made with both displays (median = 3.3%) with no significant difference, p = 0.635. In the non-pilot group, fewer roll-reversal errors were observed with the multi-layer display, but this difference did not reach significance either (median = 3.3% vs. 5.0%, p = 0.182). In both pilots and non-pilots, the reaction time was longer in the multi-layer display, which reached significance in the non-pilots (p = 0.016) but not in pilots (p = 0.215). Participants noticed that the depth was only visible during the start of the session. Conclusions. The results suggest that using stereoscopic depth cues are not a viable manner to enhance the figure-ground relation in the artificial horizon.

The current study was performed to obtain insight into the retention of combat lifesaving (CLS) skills after initial training and to compare a more individualized-style training with a more classroom-style training. We measured performance at 0 month, 2 months, and 6 months after initial training in 40 CLSers (17 individualized, 23 classroom). Each test consisted of two 20-minute scenarios with a medical mannequin to simulate combat injuries. An instructor scored the actions, which were divided into critical and non-critical by medical experts. We also measured the speed of performing the protocol and perceived mental effort and anxiety. There were no differences between the groups in critical actions. The full sample made on average almost six critical errors per scenario at 6 months. However, on non-critical actions, the individualized group scored better at 0 month. The individualized group also performed the protocol faster at each test. The classroom group reported an increase in mental effort and anxiety at subsequent tests, while the individualized group did not. Based on the high number of critical errors at 6 months, and on the drop-off in performance at 2 months, we advise that extra refresher training is organized within 2 months after initial training to improve retention further down the line.