What is a Supplemental Type Certificate?

A Supplemental Type Certificate (STC) is a regulatory approval that allows for modifications to an already certified aircraft. It is issued by the Federal Aviation Administration (FAA) or the relevant aviation authority of other countries. The STC includes technical data that validates that the changes made to the aircraft comply with safety and performance standards.

When an aircraft undergoes modifications, such as changes to its avionics, engine, or structure, the STC ensures that these alterations do not adversely affect the aircraft's safety or airworthiness. Therefore, possession of an STC is crucial for operating a modified aircraft legally, as it demonstrates compliance with the Federal Aviation Regulations.

While other options mention flight schools, pilot certifications, or licenses, they do not capture the essence of what an STC encompasses. An STC specifically addresses the approval of modifications to already certified aircraft, highlighting its importance in maintaining aircraft safety and operational integrity.