What is required for an individual wishing to introduce changes to an approved aircraft type design?

To introduce changes to an approved aircraft type design, an individual must obtain a Supplemental Type Certificate (STC). An STC is a formal approval issued by aviation authorities, such as the FAA in the United States, that allows for alterations or modifications to an existing type certificate design. This process ensures that any changes made to the aircraft meet necessary safety and regulatory standards, confirming that both the aircraft's performance and airworthiness are maintained after the modifications.

In contrast, a Type Certificate is issued for the entire aircraft design and does not cater specifically to changes. An Airworthiness Certificate demonstrates that an aircraft is in a condition for safe operation but does not authorize any design changes. An Operational Specification outlines how an operator may conduct their operations but again does not pertain to design modifications. Therefore, the requirement for an STC highlights the structured approach to maintaining safety and compliance in modifying aircraft designs.