Jump to content

Question: Standard Turn-Coordinators and Panel tilt of 14 degrees... Will it work?


Recommended Posts

Hi All,

The ancient 2" turn coordinator in my original Mooney shot-gun panel has died, and I need a replacement to finish my annual airworthy.

Got really excited about installing a R.C. Allen RCA2610-2 (2 inch) with Digital Turn & Slip Indicator in the existing 2" hole which would have put a digital horizon backup under the primary vacuum AI.  This is compliant via FAA AC91-75 which replaces a TC with a second AI having a different power source.  It would have been awesome, but unfortunately the bezel of the new instrument was too wide horizontally about 3/16 on each side, which conflicted with the adjacent altimeter and VOR/ILS instruments on either side.  Ended up returning it.  If others are considering this, it didn't fit in my M20E shot-gun panel.  I've looked into rebuilding this bad one or others found on eBay, but everyone I called said that was not viable.  Plus, aside from the RC-Allen that didn't fit, I have not found any 2" 14v replacements anywhere.

As of now, the plan is to move the 2nd VOR to the passenger side panel, slide the pilot side VOR/ILS one hole over to the right, and open 3 1/8 standard hole by the yolk.  There we plan to install a standard size T.C.

Question for the group is this... Will the 14 degree tilt on this bottom row of the panel cause problems with a standard TC?  I.E.  Will we need to install a 14 degree wedge to make it vertical OR, does the TC have the capability to function on a 14 degree tilt like this?  I have seen pictures of other Mooneys with a T.C. in this exact same location, but don't know if they are "wedged" or built to 14 degree purpose.

Any knowledge folks can pass along would be greatly appreciated!

Thanks,

Zippy_bird

Link to comment
Share on other sites

Your best bet would be to call and ask the manufacturer of the TC you're intending to buy. I had the same issue albeit with the original Garwin 2-inch T&B in my shotgun panel. It definitely had a 14-degree wedge, and I'd bet your failed TC had one too. Given my AI was also 59 years old, my solution was to completely re-do the panel into a standard 6-pack, so I bought an overhauled TC & am putting a wedge in. My TC was calibrated to zero degrees, so the wedge was necessary in the new panel. I also installed a new RC Allen AI built & calibrated to 8 degrees and it also required a wedge.

Link to comment
Share on other sites

Your best bet would be to call and ask the manufacturer of the TC you're intending to buy. I had the same issue albeit with the original Garwin 2-inch T&B in my shotgun panel. It definitely had a 14-degree wedge, and I'd bet your failed TC had one too. Given my AI was also 59 years old, my solution was to completely re-do the panel into a standard 6-pack, so I bought an overhauled TC & am putting a wedge in. My TC was calibrated to zero degrees, so the wedge was necessary in the new panel. I also installed a new RC Allen AI built & calibrated to 8 degrees and it also required a wedge.

Thanks C.J.

Exactly what I found as well. All analog TCs I researched are built to a specific mounting angle. Most being vertical mount only (0 degrees tilt). My original 2” Garwin is the dead instrument, and indeed had a 14 degree wedge installed to bring it vertical. I have a replacement 3 1/8 now, and am trying to sort how to obtain or make a wedge for it.

Any tips on wedge buying / making?

Thanks,
Z


Sent from my iPhone using Tapatalk
Link to comment
Share on other sites

There are lots of 8 degree options as lots of a/c (especially Cessna twins) have a 8 degree tilt. 14 is quite a bit - did you ask them if they (the OEM) could adjust it for 14 degrees? I have a bud with a Bo and he had one modified from 0 to 8. I do think it was RC Allen, but it’s been a while. Would make me think if they can make it work at 14.

Any electronic options that allow up to 14? I know they all have calibration options that allow 8…but the G5 installation guide doesn’t show the range of choices.

Link to comment
Share on other sites

On 9/6/2024 at 8:59 AM, Zippy_Bird said:

Any tips on wedge buying / making?

Thanks,
Z
 

You're welcome, Z.

My avionics technician made the two wedges using a 3D Printer. It's a very interesting fabrication process - just search for a YouTube video that explains it.

C.J.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.