Normalization of Deviance – The Silent Killer of Safety Culture
Aviation safety incidents rarely happen because of a single, sudden failure. Instead, many accidents are the result of gradual erosion of safety standards, where minor deviations from procedures go uncorrected until they become the norm. This is called Normalization of Deviance—the process in which unsafe behaviors become acceptable simply because nothing bad has happened… yet.
Originally studied in the aftermath of NASA’s Challenger disaster, normalization of deviance is now recognized as a widespread issue across industries, including aviation. Understanding and combating this insidious problem is a key responsibility of safety executives.
How Normalization of Deviance Creeps In
The process often begins with time pressures, operational constraints, or the pursuit of efficiency. A team might skip a checklist item or bypass a procedural step because "it’s never been an issue before." These exceptions, if unchallenged, become common practice. Eventually, what was once a violation is seen as "just how we do things here."
Some common indicators of normalization of deviance in aviation operations include:
Shortcuts in maintenance procedures – Skipping steps due to tight schedules.
Crew fatigue acceptance – Pilots and ATC staff routinely working beyond recommended duty hours.
Checklist complacency – Pilots or ground crews "signing off" on procedures without thorough verification.
Unreported minor incidents – Small deviations ignored because "nothing bad happened."
Case Studies: Lessons from the Past
NASA Challenger Disaster (1986) – Engineers were aware of faulty O-rings in cold weather but, because previous flights had launched successfully, the risk was normalized—until it led to catastrophic failure.
Boeing 737 MAX Crisis (2018-2019) – Design flaws in the MCAS system were overlooked as exceptions rather than systemic failures, leading to tragic crashes.
Runway Incursions and Near Misses – Many incidents stem from routine violations of safety margins that, over time, become standard practice until a near-disaster occurs.
How to Disrupt and Prevent Normalization of Deviance
🛑 Create a Culture of Continuous Challenge – Encourage team members at all levels to question procedures and speak up if something doesn’t seem right.
🛑 Reinforce the 'Why' Behind Safety Rules – When employees understand that rules exist due to past accidents, they are more likely to respect them.
🛑 Red Team Your Own Operations – Have independent safety reviews where an outsider audits whether processes are truly being followed.
🛑 Implement Routine 'Reset' Moments – Periodic safety stand-downs can help recalibrate expectations and remind teams of the original safety standards.
Final Thought
Normalization of deviance is a slow-moving but lethal force in aviation safety. The good news? Leaders have the power to stop it before it causes harm. By actively questioning practices, reinforcing accountability, and listening to frontline teams, aviation executives can prevent today’s exceptions from becoming tomorrow’s disasters.
How Acclivix Can Help
Addressing Normalization of Deviance requires more than just awareness—it demands proactive leadership, structured interventions, and a commitment to continuous improvement. At Acclivix, we help aviation organizations strengthen their safety culture by providing expert-led safety talks, strategic messaging, and independent safety reviews. Our tailored solutions identify risks, challenge unsafe norms, and equip teams with practical strategies to counter normalization of deviance before it leads to serious consequences. Whether you need a targeted intervention or a long-term cultural shift, Acclivix can support your organization in making safety a truly sustainable priority. Reach out today to discuss how we can help you protect your operation from the slow creep of unsafe practices.