Quote Originally Posted by Skydawg View Post
so, question remains, does anyone have any experience on what owners have done to document compliance of a non certified GPS interface?
The AIM is an excellent reference for navigation. It's states authorization to use GPS for any IFR operation is based on several factors like;

-- GPS navigation equipment must be approved in accordance with TSO-C129, or equivalent, and the installation must be done in accordance with Advisory Circular AC 20-138D or equivalent. (there's nothing in that AC that suggest an owner can prove his non-approved gear meets TSO then be good to go)

-- Aircraft using GPS for navigation under IFR may require an approved and operational alternate means of navigation appropriate to the flight.

-- The GPS operation must be conducted in accordance with the FAA-approved aircraft flight manual (AFM) or flight manual supplement.


Flying with non approved gear is not going to end well if there is loss of separation.