Need new altimeter, but it must be TSO'd?

I'm having my pitot-static system certified, but it was discovered that my altimeter isn't working correctly and I need a new one. I'm OK with that, of course, but the tech is saying that I must replace it with one that has been TSO'd? The ones from Van's aren't TSO'd and I thought one of the advantages of an experimental plane was TSO'd parts weren't necessary. Can someone clarify this for me whether I'm right or wrong? If I'm right can you tell me what I can cite for evidence? He mentioned to my mechanic that the FAA was the only one who could answer it?
Thanks for any and all advice.

Steve RV6 said:

I'm having my pitot-static system certified, but it was discovered that my altimeter isn't working correctly and I need a new one. I'm OK with that, of course, but the tech is saying that I must replace it with one that has been TSO'd? The ones from Van's aren't TSO'd and I thought one of the advantages of an experimental plane was TSO'd parts weren't necessary. Can someone clarify this for me whether I'm right or wrong? If I'm right can you tell me what I can cite for evidence? He mentioned to my mechanic that the FAA was the only one who could answer it?
Thanks for any and all advice.

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I don't believe this is correct at all. I assume you are certifying your pitot/static for IFR and there are many IFR certified planes that have glass panel which mostly are not certified, yet pass the test with no issues.

However, last time I had mine certified (including a non-TSOed glass panel) the guy told me that based on his experience vast majority of non-TSO altimeter do not pass the test.
If he is not willing to perform the test on a non-TSOed altimeter, then I think you need to look else where or having him show the FAA regulation regarding that.

Bavafa said:

I don't believe this is correct at all. I assume you are certifying your pitot/static for IFR and there are many IFR certified planes that have glass panel which mostly are not certified, yet pass the test with no issues.

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No, I'm not certifying the plane for IFR, I only want to be able to enter Class B airspace

Doesn't need to be TSO'd to enter Class 'anything' airspace, Rosie

For class B (or any other controlled airspace) you only need to have the VFR certification for transponder and altitude reporting (encoder) done.

This is where there is some gray area; the encoder must be withing 125 ft of the altimeter even though there is no requirment for VFR to certify the altimeter. If the tester notes that the altimeter is way off then what? Personally the way I see it is if the encoder is within 125 ft of the correct altitude then you're good to go on the VFR check.

It would also be foolish to fly around class B with a known altimeter error

Does the altimeter need to be TSO'd, well it depends who you ask. What's in my panel... a TSO'd Altimeter/Air Speed/VS (quality costs more in this case but it's a good value in the long run).

May not be req'd, but ...

With reference to 91.217, I would say a TSO'd altimeter is not required (note the "or" between para. 2 and 3). See what your tech says to that. However, since your goal is to mix with a bunch of aircraft with TSO'd altimeters in Class B airspace, it might behoove you to get the better quality altimeter. I can deal with a lesser quality ASI or VSI, but I'm not that good at accurately judging altitude. To paraphrase, if you can't run with the big dogs, you might better stay close to the porch!

this begs the question then to those flying a full glass panel, with non-TSOd EFIS, and zero steam gauges...does this assume then they cannot fly in class b?

You can fly in any class of airspace as long as you've had the required checks completed per 91.217 and 91.413.