Regulations are designed in the same way. We like to say, “The regs are written in blood,” and it’s often true. The Mode C veil surrounding Class B airspace is due to a mid-air with a 727 and a Cessna. Commercial pilots must have an instrument rating at night because of the Buddy Holly crash, and so on. I encourage students to adopt this way of thinking in their own flying. For the professional pilots of today this philosophy has evolved close to perfection. It has become much more granular, and it works. Today’s professional pilots are handed an operations manual that is perhaps, more truly, written in blood. This is the book that helps them operate within their limits and within the limits of the machine even when they don’t want to. There are things they can do, things they can’t do and things they must do in certain situations, all decided ahead of time.