‘Flight rules’

I recently came across the concept of Flight rules which is summarised thus:

Flight Rules are the hard-earned body of knowledge recorded in manuals that list, step-by-step, what to do if X occurs, and why. Essentially, they are extremely detailed, scenario-specific standard operating procedures. […]

NASA has been capturing our missteps, disasters and solutions since the early 1960s, when Mercury-era ground teams first started gathering “lessons learned” into a compendium that now lists thousands of problematic situations, from engine failure to busted hatch handles to computer glitches, and their solutions.

An Astronaut’s Guide to Life – Chris Hadfield

Which brought me to a 1974 report from the Apollo program containing this little nugget:

Throughout the Apollo Program, approximately 80 percent of all problems encountered in flight, both large and small, had been analyzed previously and a course of action documented before the flight. This analysis allowed the choice of a best course of action subsequent to most failures to be essentially automatic.

Apollo Experience Report: The role of Flight Mission Rules in mission preparation and conduct – Larry W. Keyser

Well worth a read.