New Avionics - How the project evolved...

Absolutely agree with everyone about non-TSO instruments & avionics being okay from a regulatory standpoint.

in my situation I'm working with a A&P/IA who charges me about a quarter of what he should, and as he's gotten comfortable with my style he gives me pretty wide latitude to do work that he's taught me, and then he inspects and signs off on it with extremely minimal expense. Sometimes it's worth making him happy by paying a little more for the TSO version - he's the one who's signing his name to it.

I think that using TSO instruments is probably a good idea from a safety point of view. However, I also think it has been pretty well settled (by AOPA pushing the issue) that an airplane certified without TSO instruments does not have to have TSO instruments, from a regulatory point of view. I usually buy the cheaper non-TSO version if an identical TSO version is also available. I'm assuming the manufacturers don't go to the expense of running two assembly lines, one being higher quality than the other. Identical instruments come off the same line and are of equal quality. The additional TSO cost is to cover liability and record keeping.

the AV-30 cannot replace your airspeed indicator, and most coupes did not come from the factory with an attitude indicator (I know they were in Alons and Mooneys), so replacing it with an AV-30 is not a big deal, and I installed the experimental version and have the AV-link as well.

Given the situation, it makes sense. I think (had you needed the AV-30) the argument could have been made in support of using it. In the future, it might be worth considering for other optional things.

I think (and don't quote me on this) that it's a grey area as far as using non-TSO instruments in an aircraft this old. My A&P wasn't comfortable with this one and he's been *fantastic* to work with so I didn't want to push it.

His interpretation is this: take the ammeter for example. The original ammeter was not a TSO instrument (which didn't exist in 1946!) so when I needed to replace it he was fine with a non-TSO ammeter as long as it was just like the original, i.e. the one sold by Univair who holds the type certificate. But if I wanted a completely different type of ammeter, he would want it to be a TSO unit.

Another deciding factor was that I purchased my Coupe from the widow of the previous owner and she was trying to sell the coupe and also her husband's semi-finished RV8 which had been left with all its avionics in an unfinished heap. It needed the AV30 more than I did.

Looks great, definitely a lot of work to bring it to 2025, some of which I'm at the early stages of now.

One question I had was since the AV-30 wasn't your primary instrument did you really need to replace it? My understanding is that as long as you have the steam gauges for altitude and airspeed you can use the experimental AV-30.