STC and rights of the manufacturer

[floatplane]

Hi guys,

hope I post in the right section...

I am interested to get more information about following question:

We are planning a STC for an existing plane (engine mount extension - not for a canadian plane).

Do we need the permission of the original manufacturer who designed/built the plane or can we do the work without asking for permission?

Any serious answers or sources for me?

Thanks in advance!

Sebastian

[CID]

You don't need permission from the manufacturer to develop an STC. (Period)

Willful participation from the manufacturer is a great advantage however and in some cases it's impossible or cost prohibitive to do certain modifications without it.