360A Slaved problems: Rebuild or replace (and then what?)

[sy308]

Sunday, in IMC (radar vectors) and the heading bug on the 360A needed constant attention for course correction.  The slave needle bouncing continually.  Unable to fly approach with the 55X autopilot, wandering right and left on inbound course.  As I got closer to the FAF, realized this was getting worse and I went missed, declared a partial panel and radar vectors to the alternate (with higher ceilings). 

So, looking into this, I have options.  It would appear that upgrading to a Garmin 275 is an option, but I would need two and a complete rebuild of the J model.  According to Garmin, this autopilot loses GPSS connectivity (which I enjoy now).  I could also think about rebuilding the 360A (at a fraction of AMU cost).  I also considered a G5 too but not sure how either Garmin unit will be with the panel mounts (GTN 650 and 750). 

Anyhow, wondering about baseline for going ahead.  One shop, says I need to update the plane for the new century and the other says rebuild, you won't be flying it in 20 yrs from now.  Yikes!

Thanks for any thoughts or assistance.

Dave

[Fly Boomer]

Bennett has one for a little over 6 AMU.

https://www.bennettavionics.com/nsd-360a-slaved-compass-system-hsi/

[Rwsavory]

I guess I'm dense, but why would you need two 275's and a "complete rebuild" to replace one HSI?  Also, it's unclear why you're concerned about a G5.

In any event, if I were you I would replace the 360 with a G5 or 275 and fly on. It will be much more reliable and cheaper to maintain than the NSD 360.

 

[Stanton R]

You wouldn't have to rebuild your panel. You would just need an adapter to change from the the 360 to GI 275 or G5. You also don't loose GPSS. 

[Aerodon]

Three basic options:

1) The NSD360 is extremely complicated mechanically and electrically, beth belts, gears etc that can wear out.  It will cost a lot to overhaul properly and even then you might get only a few more years.  You could buy someone else's 'as removed' but only get something marginally better.

2) A G5 is a nice HSI, but if you need the GAD29 box to interface to your radios. the installation, the installation gets more complex.  Its hard to flush mount in a M20J panel and looks out of place if you don't.

3) The GI-275 has become a cornerstone of the Garmin lineup, will be around for more years than the G5.  It's a very much more robust unit than the G5, and overall easier to install. Your can buy a Garmin adaptor bracket and it will fit right in where your NSD was. Also more likely to interface better with your autopilot.  

I think you or a future buyer will like your plane most with a GI-275.

 

Don

 

 

 

 

 

 

 

 

 

 

[KSMooniac]

I would go straight for a GI-275 and not hesitate, given your current state and options.  It would likely be the best balanced choice unless you could find a guaranteed functional as-removed 360A for <$1000, otherwise you're likely spending good money after bad to keep it going.

[Utah20Gflyer]

I upgraded to two GI 275s and love them.   It will undoubtedly be more expensive to go that route but you do get a lot more information like distances and times to next waypoint.   Terrain, traffic, weather etc if connected to the right equipment.   The extra cost may be offset by an increase in the aircraft value.  

[dzeleski]

On 9/13/2023 at 12:28 PM, Aerodon said:

3) The GI-275 has become a cornerstone of the Garmin lineup, will be around for more years than the G5.  It's a very much more robust unit than the G5, and overall easier to install. Your can buy a Garmin adaptor bracket and it will fit right in where your NSD was. Also more likely to interface better with your autopilot. 

 

This is not accurate. Every quote I got for 275s was several thousand more on labor. The 275 is basically a G500 and the connector is 5x the size of the G5. My installer specifically stated that a G5 install is way easier and way faster then a 275 and they do both types of installs on a regular basis. That on top of the fact that garmin forced a square interface into a round screen pushed me to G5s, and after flying in a dual 275 airplane I do not regret it. That is obviously personal preference. The ONLY thing I miss on the G5 is being able to set a minimum for an approach.

G5:

GI-275:


It also doesnt look as bad as described on a stock J panel:

[Aerodon]

Mmm, I gotta think about that one.  Two surface G5's look OK, imo one by itself sticking out hurts my eyes.

Which one is easier, I agree, there are a lot of variables.  Physically, they are about the same to mount in a 3" hole.  But with a G5 - if you need a GAD29 box for interfacing to other radios, you need to find space for that and mount it too.  Two more connectors.  Then if you want Air Data, you need a GAD13 One more connector.  Your installer had a nice easy location on the rear avionics shelf for these two boxes, and was going there anyway for the GFC500 servoes.  I have installed a GAD29 behind the panel and it took a lot of time to fabricate a bracket and mount it properly.

Both use the same GMU11 magnetometer and GTP59 temp probe.  (you can use a less expensive Davtron probe with the G5).

The GI-275 has so many more pins, because there are multiple more interfaces that you can use to hook up to analogue, arinc and HDSB GPS/Nav/sComs.  Don't count the pins and connectors and assume they all need to be connected. 

You have 2 G5's, GFC500, OAT, HDG, and a Avidyne 540.  You have 2 remote boxes (GAD13 and GAD29) remote mounted at the rear of your plane. It would be an interesting exercise, but I am pretty sure that you would have almost the exact same number of pins to connect whether you used a G5/GAD29B/GAD13 or a GI-275.    (maybe the 4 pins of the config module are extra). 

The GI-275 is the 'centre of the universe' with pigtails going to GFC500, OAT, GMU11, GPS.

With the G5, the GAD29 is probably the 'centre of the universe', with pigtails going to the GFC500, the G5, OAT, GMU11 and GPS.

I just looked a GI275 Attitude and HSI combo lists for about $8800.  A G5 Attitude and HSI with Nav interface is about $6600.  (not sure if GMU11 and GTP59 are in or out of those prices).  

Aerodon

 

 

 

 

 

 

 

[EricJ]

1 hour ago, Aerodon said:

Mmm, I gotta think about that one.  Two surface G5's look OK, imo one by itself sticking out hurts my eyes.

There's a flush-mount kit that isn't too bad to install if the G5s sitting proud of the panel bothers anybody.    I've left mine sticking out and it doesn't bother me at all, but some don't like the aesthetic.    The flush mount kit cures it pretty easily.

[LANCECASPER]

29 minutes ago, EricJ said:

There's a flush-mount kit that isn't too bad to install if the G5s sitting proud of the panel bothers anybody.    I've left mine sticking out and it doesn't bother me at all, but some don't like the aesthetic.    The flush mount kit cures it pretty easily.

@Aerodon makes and sells a nice flush mount G5 bracket 

[Aerodon]

I do, but the M20J / K panels are the tightest of all manufacturers and it does not fit nicely.  Mooney also uses 0.100 panels vs. Cessna 0.090 and Piper 0.060.

Aerodon

 

[N201MKTurbo]

I put a G5 HSI in my J in 2017 it has been flawless ever since. It was an easy install.