Startle and surprise are known to impair pilot performance during non-normal flight conditions. In the past years research has focused on developing strategies to help pilots mitigate startle and surprise responses to unexpected situations. However, no equivalent research exists for cabin crew. This study investigates the prevalence, impact on crew performance, and emotional consequences of startle and surprise among cabin crew, as well as the way in which it is currently trained. A survey was conducted among 348 European-based cabin crew to gather data on in-flight events that provoked startle, surprise, or both. Objective measures included stress ratings, perceived impact on performance, perceived emotional control, training exposure, and lasting anxiety. Qualitative data were also collected to assess crew responses and coping mechanisms. Out of 348 respondents, 79.3% reported having experienced startle, surprise or both. High stress levels were significantly correlated with perceived performance impairments and lasting anxiety. Current startle and surprise training improved perceived preparedness but did not reduce perceived stress or anxiety. Emotional control was deemed a key protective factor. Startle and surprise can cause operationally significant impact on cabin crew performance. Training that includes simple, effective emotional regulation strategies, such as those developed for pilots, is currently lacking and may help improve both immediate performance and long-term psychological resilience in the cabin environment, as may increased peer-support access.

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.

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 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.

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.

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.

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. Mnemonic procedures are currently being taught to airline pilots to manage startle and surprise. We previously tested the effectiveness of a four-item mnemonic. Pilots generally rated it as useful but some remarked that it induced too much additional workload. Therefore, we tested whether a simpler mnemonic, Aviate-Breathe-Check, would be more useful. Method. The experiment took place in a hexapod simulator with a Piper Seneca aerodynamic model and a generic cockpit. Airline pilots (n = 25) were divided into an experimental (“ABC”) and control group. All received ground training on startle and surprise, which included instructions on the ABC mnemonic for the ABC group. The mnemonic aims to support prioritization of flight-path management (Aviate), followed by physiological and mental stress management (Breathe), followed by troubleshooting (Check). All pilots performed four familiarization scenarios, during which the ABC group practiced the ABC mnemonic. Two test scenarios were then performed to evaluate performance, mental effort, stress, and pilot evaluations of the ABC mnemonic. Results. The pilots’ evaluations of the ABC mnemonic were significantly higher than those were for the previously-tested mnemonic in the same scenarios. There were no significant differences between the ABC and control group in mental effort and stress, whereas there were trends towards higher mental effort and stress with the previous mnemonic. No significant effects on performance were found. Conclusions. The results suggest that the ABC mnemonic was more useful and easier to apply than a previously tested mnemonic. This is promising for the development of effective pilot training interventions for startle and surprise.

Background: Previous research has shown that experiencing motion stimuli negatively impacts cognitive performance. Objective: In the current study, we investigate whether this impact relates to Type-II spatial disorientation (SD), to motion stimulus magnitude, or to an interaction of these factors. Method: Stimuli for participants (n = 23) consisted of Earth-vertical yaw rotations on a rotating chair in a completely darkened room. In the surprise condition, the stimulus started with subthreshold acceleration, followed by suprathreshold deceleration to a non-zero velocity, inducing a sensation of rotation that is opposite to the actual rotation revealed when the lights were switched on. In the no-surprise condition, the same changes in velocity were used, but starting from (almost) zero velocity, which induced a sensation of rotation in the same direction as the actual rotation. Participants performed a self-paced arithmetic task and measurement of their cognitive performance started after the environment was revealed. Stimulus magnitude was operationalized through higher or lower peak suprathreshold deceleration. Results: The results revealed that counting speed decreased significantly when participants were surprised, constituting a large effect size. The proportion of counting errors likewise increased significantly when participants were surprised, but only in the high-magnitude condition. Application: The findings suggest that surprise caused by the recognition of SD has an involuntary disruptive effect on cognition, which may impact performance of piloting tasks. These results are relevant when modeling motion stimuli effects on performance, and when developing SD awareness training for pilots.

Ground-based demonstration of spatial disorientation (SD) has been recommended for military as well as commercial pilot training. Although the leans illusion is the most common form of SD, no data exist yet of an effective ground-based leans procedure for a hexapod simulator. In this paper we describe the development of such a procedure and its tuning with nine subjects. The procedure was then used in an experiment with 18 airline pilots, which is described elsewhere. The final procedure started with a prepositioning phase, during which the simulator platform was slowly tilted to a 3.5° prepositioning roll angle, while the pilot performed a distraction task and the instruments and outside visuals indicated level flight. Next followed an adaptation phase, during which the pilot's vestibular system adapted to the new angle, the outside visibility degraded to zero and the instruments were covered. Then the platform was moved back to level, above the perceptual threshold, after which the instruments were shown again. The pilot was then tasked to roll back to level. The addition of the motion cues caused an increase in roll reversal errors by a factor of 3 in airline pilots. The procedure can be implemented in a scenario for demonstrating the leans in a cost-effective simulator.

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.

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.

Background: Mnemonic-type startle and surprise procedures were previously proposed to help pilots cope with startle and surprise in-flight, but effects on performance after procedure execution have not yet been investigated. Objective: Thus, we tested the effectiveness a new mnemonic-type procedure in a moving-base simulator with a non-linear model of a small twin-propeller aircraft flown single-pilot. Method: An experimental group of twelve line pilots was trained to use a four-item procedure: 1. Calm down: take a deep breath, sit up straight and relax shoulders and hands. 2. Observe: call out the basic flight parameters. 3. Outline: formulate a hypothesis about the problem. 4. Lead: formulate and execute a plan of action. A control group of twelve line pilots received a control training. Next, all pilots performed four scenarios with startling and surprising events. Data were obtained on pilot performance, stress, procedure application and evaluation. Results: Application of the procedure in the test scenarios was high (90.0% full, 100.0% partly), and pilots evaluated the procedure positively (median: 4 on a 1–5 point scale). There was significantly superior decision-making in the experimental group, but immediate responses were significantly less optimal. Pilots sometimes applied the procedure at inappropriate moments. Conclusion: The results of the tested mnemonic-type procedure were promising. The procedure may benefit, however, from modifications to reduce complexity and to stimulate application at the appropriate moment.

Several checklist-based methods have been proposed to help pilots manage startle in unexpected situations. In the current experiment, we tested how pilots reacted to using such a method, which featured the mnemonic COOL: Calm down – Observe – Outline – Lead. Using a motion-based simulator outfitted with a non-linear aerodynamic model of a small twin-propeller aircraft, twelve pilots practiced using the COOL method before performing four test scenarios involving startling events. Application of the full method in the test scenarios was high (90-100%), and pilots rated the method on average as useful (4 on a 1-5 point Likert scale). The first two steps of the method were seen as the “core” of the method. However, pilots also displayed difficulty with prioritizing dealing with immediate threats over executing the method. The results are promising, but they also warn us to be cautious when introducing a startle management method.

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.

Objective: This study tested whether simulator-based training of pilot responses to unexpected or novel events can be improved by including unpredictability and variability in training scenarios. Background: Current regulations allow for highly predictable and invariable training, which may not be sufficient to prepare pilots for unexpected or novel situations in-flight. Training for surprise will become mandatory in the near future. Method: Using an aircraft model largely unfamiliar to the participants, one group of 10 pilots (the unpredictable and variable [U/V] group) practiced responses to controllability issues in a relatively U/V manner. A control group of another 10 pilots practiced the same failures in a highly predictable and invariable manner. After the practice, performance of all pilots was tested in a surprise scenario, in which the pilots had to apply the learned knowledge. To control for surprise habituation and familiarization with the controls, two control tests were included. Results: Whereas the U/V group required more time than the control group to identify failures during the practice, the results indicated superior understanding and performance in the U/V group as compared to the control group in the surprise test. There were no significant differences between the groups in surprise or performance in the control tests. Conclusion: Given the results, we conclude that organizing pilot training in a more U/V way improves transfer of training to unexpected situations in-flight. Application: The outcomes suggest that the inclusion of U/V simulator training scenarios is important when training pilots for unexpected situations.

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.

Objective: The aim of this study was to test if performance of airline pilots, in performing an aerodynamic stall recovery procedure, decreases when they are surprised, compared to when they anticipate a stall event.
Background: New flight-safety regulations for commercial aviation recommend the introduction of surprise and startle in upset prevention and recovery training. This calls for more evidence on the effects of surprise on pilot performance, as well as methods to effectively induce surprise in training simulators.
Method: The study took place in a motion-base simulator with a poststall aerodynamic model. Using a within-subjects design, the recovery performance of 20 pilots was tested in 2 conditions: 1 anticipated condition, and 1 surprise condition. In addition to flight parameters, subjective and physiological data relating to surprise and startle were measured.
Results: Pilots had significantly more difficulties with adhering to the recovery procedure in the surprise condition compared to the anticipation condition. The subjective and physiological measures confirmed that the manipulation mainly increased surprise, and to a lesser extent also startle.
Conclusion: The results suggest that pilots have more difficulty in managing an upset situation (i.e., an aerodynamic stall) when this situation is presented unexpectedly, underlining that upset prevention and recovery training should include elements of surprise.

Introducing the element of surprise is one of the main challenges in simulator training of in-flight emergencies. In this simulator study, we investigated the differences in performance between predictable and surprising circumstances, in order to obtain insight into the transfer of training between predictable training settings and surprising circumstances in operational practice. This was done by testing twenty airline pilots who recovered from an aerodynamic stall in two conditions: one anticipation condition and one surprise condition. All pilots practiced beforehand using predictable, or nonsurprising scenarios. The results show that pilots had significantly more difficulties in adhering to components of the FAA-commissioned recovery template in the surprise condition compared to the anticipation condition. These results suggest that predictable training may not be enough to prevent serious performance decrements under surprise.