The classification criteria for Basic STCs are stipulated in Appendix C, Section II, Paragraph 6, of the , listed below:
6.2 Non-Basic STCs will generally be more complex and may require some VA involvement. Criteria for a Non-Basic STC are:
6.2.1. Changes classified as significant, in accordance with 14 CFR 21.101(b) and EASA’s Part 21A.101(b).
6.2.2. Changes requiring, or, for concurrent programs, anticipated to require, a special condition, exemption/deviation, equivalent level of safety finding, or acceptable means of compliance identified in a CA issue paper/CRI.
6.2.3. Changes introducing design features or operational capabilities identified on the VA generic VI list if the authority has published the list (see paragraph 4.5 of this Appendix).
6.2.4. Changes where the STC compliance checklist includes standards included in the VA SSD list if the authority has published the list (see paragraph 3.2 of this Appendix).
6.2.5. Any other design changes categorized as a Non-Basic STC by the CA.
6.3 All other STCs are considered Basic STCs.