Nobody Noticed the Bend

The Space Shuttle Challenger disaster wasn't a surprise. Engineers had seen the same O-ring damage on earlier, successful flights — reviewed, discussed, waved through. Nobody hid it. Something quieter had happened first: sociologist Diane Vaughan called it normalisation of deviance — the process by which a rule bent once, safely, quietly resets what "normal" looks like, until the next bend doesn't register as a bend at all. Michael Comyn traces the same mechanism into a hospital corridor — how a routine scan becomes "stat" by drift rather than decision, how a diagnosis narrows without anyone deciding to skip a step — and asks the harder question underneath: how do you tell a bend worth making from one that's quietly rewriting your baseline? Not every shortcut is a countdown to disaster. That's what makes this one hard to see coming. Keywords/tags: normalisation of deviance, Diane Vaughan, Challenger disaster, patient safety, diagnostic error, organisational culture, quality improvement, decision-making