Final answer:
As a pilot in command or a required flight crewmember, one must have both a pilot certificate and a current medical certificate readily available. This aligns with safety standards similar to preflight checklists in aviation and other industries.
Step-by-step explanation:
The question you've asked pertains to the requirements for a pilot when acting as pilot in command (PIC) or as a required pilot flight crewmember. The answer is that a pilot must have both an appropriate pilot certificate and a current medical certificate in their personal possession or readily accessible in the aircraft. Maintaining these documents ensures compliance with aviation regulations and is a part of the standardized safety procedures, much like the checklists used by pilots and astronauts to ensure the safety and functionality of the aircraft before takeoff. Notably, the pilot certification process has been scrutinized for rules that may inadvertently exclude certain groups, such as those based on height requirements, but these rules have evolved to be more inclusive over time.