COVID
Every operator faced the same virus and answered it alone. Quarantine rules, cabin sanitization procedures, and crew rest adjustments were drafted independently, then revised again as guidance shifted, sometimes contradicting the operator down the ramp. Fatigue and procedural-deviation reports moved at rates that differed sharply operator to operator, with no shared baseline for what counted as normal. A risk framework built around one operator's own numbers has no way to tell an adaptation from a drift.