Which types of inspections are mandated by the FAA for powerplants?

The correct answer highlights the specific types of inspections mandated by the FAA for powerplants, which include annual inspections, 100-hour inspections, and progressive inspections.

Annual inspections are comprehensive checks that must be conducted on aircraft at least once every 12 months to ensure they meet safety and airworthiness standards. 100-hour inspections are required for aircraft that are used for hire and involve a detailed check that must occur after every 100 flight hours. Progressive inspections allow for scheduled inspections to be subdivided into smaller, more manageable tasks that can be performed at different intervals, thereby ensuring continual oversight of the powerplant's condition.

These mandated inspections are essential for maintaining the airworthiness of aircraft, ensuring that any potential issues are addressed proactively, and enhancing the overall safety of flight operations. The other choices do not align with FAA regulatory requirements in the same specific manner as the identified inspections do.