The first tool we, along with folks from The Ohio State University and the FAA, came up with was what we called the PAVE checklist. The idea was to help give pilots a way to systematically identify the risks associated with a flight by putting them into the categories of Pilot, Aircraft, enVironment and External pressures. “External pressures” refers to those things, such as the pressure to make a schedule or to meet someone at the destination, that tend to make a pilot ignore all the other risk factors of the flight. A pilot’s hard-wired tendency to complete whatever goal he has set for himself belongs in that category. The idea behind the word “external” is that these pressures originate from things mostly outside of the flight.