What must a powerplant installed on an airplane with a Standard Airworthiness Certificate be?

A powerplant installed on an airplane with a Standard Airworthiness Certificate must be type certificated. This means that the engine or powerplant has been tested and approved by the FAA for use on a specific model of aircraft, ensuring that it meets all required safety and performance standards. The type certification process involves rigorous evaluations, including tests on reliability, performance, and safety, which are essential for the appropriate functioning of the aircraft as a whole.

In contrast, while a powerplant being certified for flight or undergoing regular inspections is essential for operational safety, these aspects do not necessarily confirm that the powerplant has undergone the comprehensive evaluation required for type certification. Similarly, repairing to specifications is important for maintenance and ensuring continued airworthiness, but again, this does not equate to the initial certification process that validates the powerplant's design and performance for its intended application.