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:
Effects of acute stress on aircrew performance: Literature review and analysis of operational aspects´
WHAT?
Analysis by research scientists at NASA integrating cognitive science, aviation psychology and accident data to understand how acute stress degrades pilot performance, particularly during abnormal or emergency situations that demand rapid problem-solving and coordination.
WHERE?
NASA Ames Research Center, with supporting work from the University of New Mexico.
WHEN?
Published in 2015. Accident analyses and literature reviews from 2014.
WHY?
Acute stress impairs the cognitive functions aircrew rely on during non-normal events. Helicopter operations with high workload, dynamic environments, and more frequent exposure to accidents and serious incidents, are particularly susceptible. The study sought to translate theory into practical operational risk insight.
HOW?
The study consisted of
1. A review of human-factors research on stress, cognition, attention and memory.
2. Investigation of 12 accidents involving 212 pilot errors coded into categories.
3. An operational analysis to identify practical design, training and procedural interventions to mitigate stress-induced vulnerabilities.
FINDINGS:
1. Attention becomes threat-biased and narrowed
Under stress, pilots shift to bottom-up, stimulus-driven attention, losing the ability to prioritise tasks or notice subtle cues. This increases risk of obstacles, deteriorating weather cues, altitude/airspeed deviations, or unnoticed automation changes.
2. Working memory collapses under load
Stress consumes cognitive bandwidth, impairing situational model updating, mental calculations, and remembering procedural steps.
3. Decision-making becomes rushed and shallow
Stress pushes crews to simplify reasoning, rely on incomplete mental models, or commit prematurely to a course of action.
4. Communication and coordination degrade
Thirty of the analysed accident errors involved communication failures, and many errors of omission reflected breakdowns in task management.
5. Well-practised skills remain resilient, but novel tasks do not.
Stress impairs problem-solving but, highly proceduralised actions are less affected. Many accidents occur during unexpected, context-specific emergencies (e.g. brownout, wire strikes, inadvertent IMC). Training should therefore include scenario variability and cognitive flexibility, not solely mastery of SOPs.
SO WHAT?
Aircrew performance in emergencies cannot be understood without considering stress-driven cognitive degradation. Acute stress is not a background factor, but actively reshapes cognition in ways that create specific, predictable error pathways.
For helicopter operations, which already feature high workload, unpredictable dynamic environments:
- Procedures should be designed to be cognitively supportive under stress, with simplified steps, salient cues and improved error-trapping.
- Training should include stress inoculation, scenario-based practice and dynamic task-management exercises relevant to low-level flight, degraded visibility and high-risk mission profiles.
- Interfaces and checklists need to reduce working-memory demands and enhance attentional guidance.
- Crew coordination should be deliberately trained for emergency conditions as well as routine phases.
- NextGen/advanced avionics should be designed with human stress limits in mind to prevent automation surprises.
REFERENCE:
Dismukes, R. K., Goldsmith, T. E., & Kochan, J. A. (2015). Effects of acute stress on aircrew performance: Literature review and analysis of operational aspects (NASA/TM—2015–218930). NASA Ames Research Center.
competentaviators.com 