My op limitations allow IFR if aircraft meets IFR requirements. This is same limitation as AB as far as I can tell, including same limitation reference # from FAA matrix. As far as RNAV GPS approaches go, my question is does anyone have any specific policy guidance in what the EXP owner would need to do to be compliant in using a non certified GPS as primary nav? My limits just require me to meet the requirements of 91.205(d), which does not mention equipment must be certified. Only other reference to GPS I can find is AC-138 which basically says GPS does not need to be manufactured under a TSO but it must meet same requirements, which would leave it up to aircraft owner to prove it meet meets same requirements.

so, question remains, does anyone have any experience on what owners have done to document compliance of a non certified GPS interface? As far as flying RNAV approach in IMC, I don’t intend to, but would like the legal ability to file IFR with GPS as primary navigation and maybe shoot RNP approach in VMC if available.