Every winter, aircraft depart in snow and freezing rain under a simple but unforgiving rule: a clean aircraft flies. That rule was shaped by tragedy. In this episode, we revisit the 1982 crash of Air Florida Flight 90 - a disaster that exposed the deadly consequences of ice contamination and inadequate thrust on takeoff, and helped transform winter flight standards. The lessons from that day reshaped deicing procedures, crew training, and federal regulations that still govern cold-weather operations. We’re joined by retired airline captain and aviation safety expert Steven Green, whose four decades of flying and deep work in aircraft icing and accident analysis bring critical perspective to the science and the stakes. Together, we examine how ice disrupts flight, the crashes that rewrote the rules, and why the margin for error in winter aviation remains razor thin.