[Rick_A]

I met with guys at my local avionics shop to discuss getting my initial pitot/static & transponder check. Their view is that I would be better off getting a TSO'd encoder (they have never certified a transponder with a non-TSO'd encoder).

My present configuration is using the serial out from my GRT Horizon to a GNS 480. The 480 then sends Altitude data to the Garmin 327 (this is how Stark wired my harness).

From the research I've done, it appears that if I get a encoder that has RS232 output, I should be able to disconnect one wire from the GRT and it connect to the TSO'd encoder. I would be interested in hearing from anyone that has changed from an EFIS to a TSO'd encoder. If by chance anyone has done this to Garmin 480, I like to know what data protocol you used.

The avionic shop suggested Trans-Cal Nano model #SSD120-30NRS232 (best price I've found is $313). Has any one used this encoder or have suggestions for other encoders? This one is real small, so I like that.

Thanks.

 

[Radomir]

I personally do not think that would be necessary... just because some shop is not familiar with experimental market wouldn't mean you have to jump through additional hoops and expense...

Plenty of GRT systems out there (and to be fair, others too) passing IFR cert requirements and holding up to those standards..

I met with guys at my local avionics shop to discuss getting my initial pitot/static & transponder check. Their view is that I would be better off getting a TSO'd encoder (they have never certified a transponder with a non-TSO'd encoder).

My present configuration is using the serial out from my GRT Horizon to a GNS 480. The 480 then sends Altitude data to the Garmin 327 (this is how Stark wired my harness).

From the research I've done, it appears that if I get a encoder that has RS232 output, I should be able to disconnect one wire from the GRT and it connect to the TSO'd encoder. I would be interested in hearing from anyone that has changed from an EFIS to a TSO'd encoder. If by chance anyone has done this to Garmin 480, I like to know what data protocol you used.

The avionic shop suggested Trans-Cal Nano model #SSD120-30NRS232 (best price I've found is $313). Has any one used this encoder or have suggestions for other encoders? This one is real small, so I like that.

Thanks.

 

[Martin Sutter]

I agree with Radomir. My 7A is IFR certified with the encoder output from the GRT Horizon I to a GTX327. The shop had no problem doing that as they had researched the regs and came to the conclusion that the encoder did not have to be TSO'd in an experimental installation as long as it met the performance specs of the TSO. As it turned out the GRT encoder was well within the parameters specified.

Martin Sutter
building and flying RV's since 1988

 

[SteinAir]

Hi Rick,

#1) No need for a TSO'd encoder. I've yet to see an EFIS fail a check...some we've done have needed some tweaking, but never a full up fail.

#2) No need to spend that big of bucks on an encoder. If you want/need the 232, get an A30.8

The shops that are scared of EFISes are typically very inexperienced with them and just not educated with them. It's clearly not the FAA who is saying that, because we along with many other FAA certified shops perform said checks routinely and others do it all over the country. Sometimes you'll have a newbie inspector from the FAA that needs to be educated, but overall most of the FSDO guys I've talked to around the country who are "in the know" are fine with it.

My 2 cents as usual.

Cheers,
Stein

 

[Rick_A]

Thanks for the input. I'll see if I can get the shop to re-consider and let me use the GRT (or look for another shop). I'll put off buying the Tran-cal and check out the A30.8 (thx, Stein).

Martin, please contact me via a private message or email (raronow at sbcglobal.net) to get the name of you avionics shop. If I refer my guy to another shop, I'm sure it will mean a lot more then coming from my mouth.

 

[Mel]

Before I changed my encoder over to the Dynon, I talked with my transponder guy. He told me that he has never found a Dynon encoder to be off. I changed mine over and it has never failed to pass.