"CivetOne" wrote in message
...
Hi guys,

Let me jump into the middle of this with both feet, and hope to escape
without
too many flames...

14 CFR part 21 contains the procedural rules for obtaining a type
certificate
and approval for changes to a type certificate

Yes.

(i.e., a Supplemental Type
Certificate),

No, that is Part 23 for under 12,500 lbs.

snip of rest without reading

Let me be fair to the FSDO guy and agree that the icing capability is
usually added after the Part 21 Type Certificate is issued. Therefore, if
you have anti-icing capability for your small airplane, it is probably a
Part 23 STC change.