Final answer:
The remote pilot in command (PIC) is responsible for ensuring enough crewmembers for a small UAS operation, similar to how pilots and truck drivers are monitored for operational hours by the FAA.
Step-by-step explanation:
The person responsible for ensuring that there are enough crewmembers for a given small Unmanned Aircraft System (UAS) operation is typically the remote pilot in command (PIC). The PIC must ensure that all aspects of the flight are safe, which includes having the proper number of qualified crewmembers available to handle the operation. The importance of crewmember availability is similar to how pilots and truck drivers are regulated in terms of operational hours by the Federal Aviation Administration (FAA) to enhance safety and avoid accidents. Use of checklists is another critical safety measure found in various professions, as illustrated with the WHO surgical checklist and the checklists pilots and astronauts use before taking off.