cjcampbell wrote:



STCs are part of the airplane's type certificate. You have to keep them
in the plane,

Wrong, you need not keep any STC 337 in the plane. There may be a POH
supplement that must be kept in the plane, most commonly found with a
new IFR GPS install.


along with any manuals pertaining to the new equipment --
those become part of the operating handbook.

The manual need not be in the airplane unless the STC says it has to be
there. It may be a good idea, but not required.