Concorde

Britain and France spent decades and a fortune building the Concorde, a supersonic passenger jet that crossed the Atlantic in three and a half hours. By the mid-1960s, insiders already doubted it would ever pay for itself. It flew anyway, from 1976 until 2003, operated by just two airlines while almost every other carrier that had options to buy quietly walked away. The economics never worked at scale, yet the project kept going year after year.

For founders and operators, this is the case that sharpens one of the hardest calls you face: when to kill something you have already poured money, time, and reputation into. Every business has a Concorde, a project kept alive by what it cost to get here. The question of how to decide whether to continue or stop is one most leaders get wrong, and this story shows exactly why.