In aviation, safety largely depends on precise adherence to procedures, continuous training, and maintaining a high skill level. Yet even the most experienced pilots are not immune to subtle psychological mechanisms that lead them to unconsciously accept minor deviations from safety standards. These phenomena include “Normalization of Deviance,” “Procedural Drift,” and “Skill Decay.”
These phenomena stem directly from the natural workings of the human mind, which instinctively seeks simplifications and convenient solutions. As a result, pilots often unintentionally accept situations and behaviors that initially would have seemed unacceptable. Gradually, this increases risk during flights, potentially leading to serious incidents or disasters.
In this post, we’ll briefly discuss selected phenomena, illustrate them with concrete examples, and outline proven strategies to help pilots maintain high safety standards, manage risks effectively, and protect themselves and their passengers from the consequences of cognitive errors.
What is Normalization of Deviance in Aviation?
This term was popularized by sociologist Diane Vaughan following the Challenger Space Shuttle disaster in 1986. Vaughan described a process where gradual deviations from procedures become normalized, ultimately leading to catastrophe. Aviation experiences a similar pattern—minor deviations from established rules initially seem harmless but gradually become entrenched, until pilots no longer realize they’re operating outside safety guidelines.
Examples include:
- Becoming accustomed to minor SOP (Standard Operating Procedures) violations—like imprecise checklists or incomplete pre-flight briefings.
- Accepting “faster” shortcuts—such as expedited approaches or incomplete pre-takeoff checks.
- Trusting “well-trodden paths”—believing something that’s worked for years doesn’t require revisiting basic standards.
Skill Decay—Deterioration of Skills
When pilots complete their training and stop regularly practicing under instructor supervision, their skills can gradually deteriorate—a phenomenon known as “Skill Decay.” Lack of regular practice reduces precision and effectiveness.
Examples in practice:
- Pilots rarely performing instrument approaches (IFR) may begin making navigational errors.
- Occasional flyers might struggle to react appropriately in emergencies due to lack of ingrained reflexes.
- Without regular instructor check flights, pilots often fail to recognize their mistakes.
Procedural Drift—Quiet Departure from Standards
Another related phenomenon is “Procedural Drift,” the gradual departure from standard procedures, often driven by routine, fatigue, or assumptions that “it doesn’t matter.”
Common symptoms:
- Skipping checklists because “everything works anyway.”
- Shortened briefings because “we’ve flown this route and crew for years.”
- Careless flight planning because “we know the route by heart.”
How to Avoid Cognitive Pitfalls Facing Pilots?
- Regular training and check flights—periodically flying with an instructor to receive critical feedback.
- Strict adherence to checklists and procedures—even seemingly unnecessary tasks significantly reduce error risk.
- Self-review of flights—recording and reviewing approaches to spot and correct mistakes.
- Openness to feedback—accepting observations from colleagues when you start developing shortcuts.
- Practicing emergency scenarios—regular drills maintain pilot proficiency even if not mandated.
Staying Connected with Instructors—The Key to Maintaining High Skills and Safety
Therefore, it’s crucial for pilots to remain in close contact with training facilities and instructors who understand not only aviation principles but also the specific aircraft pilots operate. Regular refresher sessions can identify unnoticed errors.
An excellent example is the Cirrus Recurrent Training program, which offers refresher training for both VFR and IFR pilots. Although this should be standard practice, it is often overlooked or undervalued. Pilots who consistently participate in such programs maintain their skills at a high level and learn new techniques and best practices from experienced instructors.
In summary, flying is a skill that requires continuous improvement. Nobody is immune to phenomena that degrade skills, but awareness, regular training, and openness to correcting mistakes can significantly enhance safety. Adhering to established standards and investing in regular training protects not just pilots, but everyone in the air.
