In 2023, the FAA's NOTAM system — an obscure but critical flight-safety database that traces its roots back to Cold War-era teletype machines — crashed overnight and held every American airplane on the ground until the sun came up. The culprit wasn't a cyberattack or a solar flare; it was a single corrupted file, placed there accidentally by a maintenance technician trying to fix something else. This week we dig into how a system nearly 60 years old ended up responsible for the safety of 45,000 daily flights, and what it means that nobody noticed how fragile it was until it wasn't.