The “turkey illusion” is a simple story with a powerful lesson: past comfort does not guarantee future safety. Nassim Taleb used the turkey parable to show how repeated benign observations can mask rare, catastrophic events — the so-called “black swan”. In aviation, operators, regulators, and crews can fall into the same trap when they rely on stable histories and ignore signals that a rare event might occur. This article explains the parable in plain terms and translates it into practical safety steps that align with industry requirements and good safety management practice.
The turkey story and what it means for risk perception
The turkey is fed every day and grows confident that life will continue as it always has. On the day it is slaughtered, that prior experience is irrelevant. In risk terms, the turkey illusion highlights a cognitive bias: we overweight frequent, recent observations and underweight rare but consequential events. In aviation this appears when operators treat low incident rates as evidence of low risk, without checking the assumptions behind their data or considering which hidden dependencies could fail.
Why aviation is vulnerable: organizational blind spots and regulation
Aviation is highly regulated and data rich, which reduces many risks. Yet regulations and procedures themselves can produce blind spots if they create a false sense of completeness. ICAO Annex 19 and the ICAO Safety Management Manual (Doc 9859) require service providers to implement Safety Management Systems (SMS) that identify hazards, assess risk, and monitor controls. These frameworks are designed to catch hidden threats, but only if organizations actively challenge assumptions and test controls. Similarly, FAA and EASA guidance encourage continuous monitoring and reporting. Compliance with rules is necessary but not sufficient; firms must also ensure their risk models consider low-frequency, high-impact scenarios and the potential for systemic failure.
Practical steps to counter the turkey illusion
Start by treating assumptions as testable hypotheses rather than facts. During safety reviews and risk assessments, document key assumptions about system reliability, human performance, and operational environments. Use scenario-based exercises to explore what happens when those assumptions break down. For example, simulate simultaneous failures, degraded communications, or unexpected weather patterns and observe whether existing procedures and recovery plans remain effective.
Encourage a reporting culture that surfaces anomalies and near-misses. Under ICAO Annex 19 and many State regulations, non-punitive reporting and protection of safety data are central to SMS. Make it easy for frontline staff to report concerns and ensure reports trigger timely analysis rather than being filed away. Use trend analysis and root cause investigation to detect slow-moving issues that routine checks might miss.
Integrate horizon scanning and change management into the safety cycle. When introducing new technology, routes, or suppliers, perform a focused risk appraisal that looks beyond immediate effects to second-order consequences. Management of change processes should require evidence that safety performance indicators and probability estimates are still valid after the change.
Adopt stress-testing and diversity in risk assessment. Complement historical data with expert judgment, red-team reviews, and probabilistic modeling that includes heavy-tailed events. Regularly review and update safety performance targets (SPTs) and indicators to ensure they reflect exposure to rare events, not just averages. Where possible, cross-validate assumptions against external data sources and industry intelligence.
Finally, ensure governance translates analysis into action. Senior management must sponsor periodic independent reviews that challenge complacency. Regulators expect service providers to show that their SMS is proactive and effective; evidence of robust assumption testing, realistic scenarios, and corrective action plans will meet both safety and compliance expectations. For practical templates and guidance, organisations can refer to ICAO Doc 9859 and relevant State/Sector SMS guidance on regulator websites .
Conclusion
Assumptions that go untested create vulnerability. Treat safety assumptions as hypotheses to be challenged through scenarios, reporting, and stress tests. Make sure SMS processes include management of change, horizon scanning, and visible governance so that rare, high-impact events are considered before they occur.
The organisation should routinely question what a single failure or surprise would do to operations and ensure corrective measures are actionable and resourced. By doing so, aviation operators will be better prepared to spot the turkey illusion early and prevent unpleasant surprises.