I bring you a weekly bite-sized chunk of the science behind helicopter human factors and CRM in practice, simplifying the complex and distilling a helicopter related study into a summary of less than 500 words.
TITLE:
Startle and surprise in helicopter operations: Reported prevalence and application of mitigation strategies.
WHAT?
Study investigating how often helicopter pilots experience startle and surprise (S&S) events, how stressful and mentally demanding these are, what coping strategies are currently used, and whether helicopter crews would accept a structured startle management technique such as “Aviate, Breathe, Check” (ABC).
WHERE?
Conducted by Cranfield University, Delft University of Technology, and TNO Human Factors researchers using an international sample of helicopter pilots from military, offshore, HEMS, SAR, police, aerial work, and commercial operations.
WHEN?
Published in 2025 in the journal Cognition, Technology & Work.
WHY?
While startle-management techniques are increasingly used in fixed-wing airline operations following accidents such as Air France 447, little was known about their relevance to rotary-wing flying. Helicopter operations are uniquely challenging in terms of human factors and expose crews to factors such as:
- Low-level flying in the obstacle environment
- Degraded visual environments
- Time pressure
- Significant manual flying demands
- Unpredictable and dynamic operational demands
These conditions potentially increase vulnerability to startle and surprise, which is known to impair decision-making, communication, and situational awareness.
HOW?
234 helicopter pilots were asked about their operational experiences with startle and surprise. They reported:
- The types of events encountered
- Perceived stress and mental effort
- Coping strategies used
- Views on the feasibility of the ABC recovery method
The ABC method is a short startle and surprise recovery technique intended to interrupt the stress response:
- Aviate – stabilise and control the aircraft
- Breathe – use controlled breathing to reduce physiological stress and cognitive overload
- Check – deliberately rebuild situational awareness using instruments and sensory cues
Statistical analysis compared responses across experience levels and military versus civilian training backgrounds.
FINDINGS:
96% of pilots had experienced significant startle and/or surprise events during operations.
The most commonly reported events included:
- Failures with no clear cause
- Bird strikes
- Inadvertent IMC
- Automation surprises
- Disorientation and tail rotor events
Tail rotor emergencies and disorientation scenarios generated some of the highest reported stress and mental workload levels.
Importantly:
Stress and workload effects were similar regardless of flying experience.
There were no major differences between military and civilian pilots.
Most pilots relied on generic strategies such as:
- “Fly the aircraft”
- Revert to training
- Follow procedures
Only 1% had formally trained a breathing-based recovery method. However, around 90% were open to using a structured method if properly trained. The main concern was whether there would be enough time to apply it during rapidly developing emergencies.
SO WHAT?
This paper highlights how common and operationally significant startle and surprise are in helicopter flying, given the high workload, low altitude, and manual flying demands.
The study suggested that experience alone does not appear to protect pilots from the cognitive effects of surprise. Even highly experienced crews reported substantial stress and mental effort.
For training organisations, the findings support the importance of:
- Scenario variability.
- Unpredictable simulator training.
- Deliberate stress-management techniques.
- Training recovery from cognitive overload, not just technical failures.
The strong acceptance of the ABC method suggests helicopter operations may benefit from structured cognitive reset techniques similar to those now appearing in advanced airline training.
REFERENCE:
Vlaskamp, D., Pollitt, A., Blundell, J., Landman, A., Groen, E. L., van Paassen, M. M. R., Stroosma, O., & Mulder, M. (2025). Startle and surprise in helicopter operations: Reported prevalence and application of mitigation strategies. Cognition, Technology & Work, 27, 579–590. https://doi.org/10.1007/s10111-025-00811-y
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