|Twisted-Wrench LLC Aircraft Maintenance Special Projects
|A supplemental type certificate (STC) is a type certificate (TC)
issued when an applicant has received FAA approval to
modify an aircraft from its original design. The STC, which
incorporates by reference the related TC, approves not only
the modification but also how that modification affects the
|Where can I find information about STCs installed on my
If you need information about supplemental type certificates
that have been installed on your aircraft, you may:
The maintenance provider will record the installation of a
The regulatory requirement for STC Permission was
added to the regulations in 2006.
Previously installed STCs were not exempted from this
Prior to this change, a copy or the cover sheet of the STC
should have been in the records with the FAA Form 337.