Supplemental Type Certificate (STC)

Supplemental Type Certificate – an STC supplements the original Type Certificate (TC) issued by the manufacturer of an aircraft or engine. The supplemental type certificate is issued after a major modification of an aircraft, which normally significantly changes the aircraft’s operational characteristics. A good example of an STC would be the installation of winglets on an aircraft which originally was not winglet equipped. STCs are issued by Part 21 organizations and the aircraft OEM and approved by EASA/FAA directly