I believe there is general agreement among competent professionals that any original non-TSO instrument in an Ercoupe can be replaced with another non-TSO instrument under applicable regulations. Replacing one Stewart-Warner ammeter with another should be a "minor alteration" (Log book entry, no FAA involvement).
Replacing the original ammeter with a Davitron 5-function instrument would probably require a 337 (field approval). That said, any installation must be properly accomplished and signed off by your mechanic. If he/she is not OK with installing non-TSO replacements, perhaps time to consider a more confident mechanic. Understand, I'm NOT a mechanic. Regards, WRB -- On Aug 28, 2010, at 22:25, n611gc wrote: > I have a question for the legal minds of the board. Is it legal to > replace an original instrument in a 415C with a non-TSO'd instrument? > tia, Rick >
