A Supplemental Type Certificate (STC) is a document issued by Transport Canada to approve a change to the type design of:
- an aeronautical product identified in the document by a single serial number
- several aeronautical products of the same type or model, approved under a single type certificate and identified in the document by their serial numbers
- several aeronautical products of differing types or models, approved under separate type certificates and identified in the document
Changing the type design of a product can be easy or complex, so the scope of work will depend on the complexity of the design change.