Looking for Suggestions on Replacing an old Narco MK-12D

[Leo Langston]

Well one of mymold Narco MK-12Ds is finally biting the dust. The orange displays are failing fast. This just started in the past 3 weeks. It’s still useable for AWOS but I need to look for replacement options. I recently upgraded the panel in my Navion with Aspen 2000 Pro Max displays and GNX 375 GPS transponder. So I probably need to stay in the Garmin family. My remaining good Narco has the GS for ILS but I could get a 255A or move up to. 650xi or even a 750xi. Not sure I can fit a 750 in the panel without some major cutting and box rearrangement. My question is do I really need the large 750 display since I have the Aspen MFD? I have the PMA-450B audio panel so I don’t need the 750s functions. So I am looking for suggestions on replacing the lower Narco in this panel pic. The avionics stacks can’t really go any higher in the panel due to obstructions back up under the panel. There is a defroster vent up behind the Narcos and a structural rib up above the 55X. If something has a shorter chassis length than the Narcos it could go up slightly higher than the upper Narco in this pic.

Suggestions?

Thx
Leo

 

[asicer]

So I probably need to stay in the Garmin family.

Not really. Your panel already has a mishmash of different brands.

My question is do I really need the large 750 display since I have the Aspen MFD? I

"need"? No. Might be nice, though.

So I am looking for suggestions on replacing the lower Narco in this panel pic.

Do you really need a 2nd NAV/COM? Or will simply a COM be enough? If NAV/COM, there's really only 2 choices unless you want to install something used or switch to a GPS/NAV/COM like a GTN: Garmin GNC255 and Trig TX56a.

If you really need that 2nd NAV radio, you could also install separate NAV and COM. Keep in mind that no matter what NAV you install, looks like you're going to also need a new CDI unless you go the VAL INS429 route.

 

[Leo Langston]

I was considering another GPS/ Navcom just to have a backup GPS and a replacement Navcom with GS for ILS when and if the other Narco craps out. Since I have the Garmin 375 GPS navigator and know it’s buttonology I didn’t think adding a Avidyne would make sense. Do most folks think having a backup GPS makes sense when paired with one decent ILS capable Navcom? A good SL-30 would work but they are hard to come by.

 

[asicer]

Do most folks think having a backup GPS makes sense when paired with one decent ILS capable Navcom?

I’m not a fan of backing up a GPS navigator with another GPS navigator, but that’s a bit of a personal thing. I have the VOR MON and my tablet available if GPS goes out. And jammed satellites takes out both your primary and backup units.

A good SL-30 would work but they are hard to come by.

Trig TX56a is more or less equivalent to a brand new SL30.

 

[Leo Langston]

Good point. I see many planes with a 750 & 650 setups so I figured a backup GPS would be a good option. Currently the top Narco is connected to the Aspens and the lower unit is connected to its original CDI to the left of the Aspens. The Aspen can take 2 digital Nav inputs but only 1 analog input so the second Narco had to go to its old CDI. With a new digital Nav input I could connect that to the Aspen along with the old Narco analog signal and not need to old CDI. Or I could just replace the old VOR CDI with the VOR/GS CDI and just drive it with the remaining good Narco.

 

[asicer]

With a new digital Nav input I could connect that to the Aspen along with the old Narco analog signal and not need to old CDI.

Both the GNC255 and TX56 have digital outputs that can drive the Aspen.

Or I could just replace the old VOR CDI with the VOR/GS CDI and just drive it with the remaining good Narco.

I personally like a 2nd CDI in case something happens to the Aspen. That said, both the TX56 and GNC255 have on-screen CDI (horizontal only, though).