Replace AH or TC

[Joshua Blackh4t]

So I'm getting an AV-30c in the basically original dash of my E. This is a big thing for me, I can only dream of the big glass panels and the money and downtime they take.

My question is: should it replace the vacuum AH or the electric TC?

If it fails at night, I'd prefer to have a backup AH. Also, it already has the 2 amp breaker.

However I'd lose the manual balance ball and the dubious usefulness of knowing a rate 1 turn.

Is there a rule on needing one of each or am I right in believing that I can replace either?

Thoughts?

Cheers,

Joshua 

[Ned Gravel]

I bought a G5.  Installed it as an HSI.  If the AH fails, it can be switched to take over that function. And it still retains the HSI info and drives my STEC autopilot. 

[JimB]

If it was me, I'd move your vacuum attitude indicator down to where your TC is and get rid of the TC. Then install the AV-30C as the primary Attitude reference if you like the display the AV-30C provides. I think that is doable per AC91-75 and you will have good redundancy then. 

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC91-75.pdf

Edited December 2, 2022 by JimB

[JimB]

Also consider if your autopilot or wing leveler (if you have it and its working) needs the TC

[jamesm]

I was having my turn coordinator die or at least having to pull it to troubleshoot every 3 to 4 years. As much as I wanted install a third  G5 to  replace the turn coordinator. The Garmin G5 STC won't allow me install a 3rd G5. I have to choose between  Attitude indicator or Turn coordinator.  I was getting annoyed and went the expensive route installed a RCA 2610-3P Mini 6 from RC Allen. It's  more money than the G5 but it has all the associated TSO's for it's functions (Airspeed,Altimeter, Heading, Rate or turn, ball, Rate of climb, 3hrs back battery up).  It my understanding the AV-30C , Garmin G5 , Dynon where qualified under Non Required Safety Enhancing Equipment (NORSEE)  equipment and a STC.  I am not sure if AV-30C STC would allow change out both the Attitude and Turn Coordinator with one instrument. The referenced  AC91-75 document calls out the TSO-C4c, Bank and Pitch Instrument. I don't believe the NORSEE equipment fall under the TSO'd category of  certification though could be wrong on this. 

It may sound foolish, but I figured that  AC91-75 allows me to replace my Turn coordinator with an attitude indicator  since both instruments were TSO'd instruments. In theory my installation should be "Legal" in the eyes of the FAA. Plus having a standby instrument made from totally different company less likely software bug/feature totally grounding me at least in theory. The RCA 2610-3P Mini 6 Holds: TSO-C4c, TSO-C113a, TSO-C3e and TSO-C6e, TSO-C2d, TSO-C10c and TSO-C8e. I can switch between Mag head and ground track it also has heading/ altitude bugs.  it has a bit cumbersome menu  probably the location makes  most awkward to use but never the less it works.  Though the headings between the G5 and  RCA 2610-3P rarely seem to perfectly  agree.  but  probably more reliable than vacuum instruments or whiskey compass. One thing I really like about Garmin equipment is that their rotary encoders on all the products I own are solid they have real nice positive detent to the feel. Whereas the RC Allen, Aspen, Sandia  and other equipment that I have used it was too easy to bump and change a setting.

 

Just my 2 cents,

James '67C

 

[65MooneyPilot]

My PC, on my E model, does not require the TC. Some do depending on which one you have installed. I left the TC in.