Garmin-to-Sandel link somtimes doesn't work

Guest Discussion
1

Sometimes the ARINC 429 channel from the #1 Garmin 430 to the Sandel doesn’t work. The symptom is that the Sandel can’t display the moving map, the glide slope indication, or the CDI.

Sandel has seen this problem before and doesn’t know what causes it yet.

If this has happened to you, please let me know so we can pool our knowledge of the problem.

I think I have found that if I turn the avionics master on soon enough after the HSI is turned on (which is when the masters on turned on), that the problem does not happen.

Also, I found that the problem never happens if the Sandel is in maintenance mode. However, I am reluctant to fly around with the Sandel in this mode. But that I can always make it work this way suggests a software bug.

Sandel also thinks it is a software bug, but they don’t know if the problem is with the Garmin or the Sandel.

Robert Bedichek

2

I have seen this behavior before, however I attributed it to an intermittent connection between the Sandel and GPS1 (I am still having problems with the Sandel DG operation).

The symptoms were:

NAV1 would not display on RMI (all —)

No GPS data sent to HSI (no map, CDI flagged)

No VOR/LOC/GS data sent to HSI (no display)

NAV2 showed up in the RMI just fine, ARNAV was working fine, GPS1 displayed info fine. GPS2 and CDI2 were working fine.

Please let me know what you find out.

Paul

3

Sometimes the ARINC 429 channel from the #1 Garmin 430 to the Sandel doesn’t work. The symptom is that the Sandel can’t display the moving map, the glide slope indication, or the CDI.

…

I’ve also had this problem occasionally. Cycling the power to the Sandel has always fixed it. You have to pull both HSI breakers to do do this.

-Mike

4

FYI: I just had this happen on my last leg yesterday. SR 22, ser.#56, N2ZH.

Nav 1 starts out flaged on the HSI. Nav 1 still will work with the autopilot (GPSS) and the autopilot will still work with the heading bug on the HSI. Also Nav 2 shows up fine on the HSI.

Include me if there is a cure.

Sometimes the ARINC 429 channel from the #1 Garmin 430 to the Sandel doesn’t work. The symptom is that the Sandel can’t display the moving map, the glide slope indication, or the CDI.

If this has happened to you, please let me know so we can pool our knowledge of the problem.

I think I have found that if I turn the avionics master on soon enough after the HSI is turned on (which is when the masters on turned on), that the problem does not happen.

5

FWIW - it sometimes happens in my 260SE.

6

The problem has gone away on my SR22 after about 20 hours of operation where it happened every time (except while in maintenace mode).

Before it did, I found that I could always make the GNDS 430-to-Sandel connection work by going into maintenance mode of the Sandel. (Hold the outer two buttons on the bottom edge down during power-on). I just flipped through the setup pages until I got to the normal-operation screen. However, I don’t like flying around in maintenance mode. Anway, this strongly suggests a software bug, either in the the Garmin or in the Sandel.

Last I heard from Sandel, they thought it was likely a software bug or incompatility. They have had reports of the bug coming and going in various aircraft, not just Cirrus’s.

For me, if the Sandel started up with the CDI/GS/Map working, it stayed that way for the whole flight.

Now that the bug has gone away, I’m not sure how to go about tracking it down further. I’ll have to wait for Sandel to tell me something or for the bug to reappear.

But if it does come back, I know about it while still on the ground and if I really want it to work (e.g., not a nice VFR day), I can reboot the Sandel in maintenace mode.

I have seen this behavior before, however I attributed it to an intermittent connection between the Sandel and GPS1 (I am still having problems with the Sandel DG operation).

The symptoms were:

NAV1 would not display on RMI (all —)

No GPS data sent to HSI (no map, CDI flagged)

No VOR/LOC/GS data sent to HSI (no display)

NAV2 showed up in the RMI just fine, ARNAV was working fine, GPS1 displayed info fine. GPS2 and CDI2 were working fine.

Please let me know what you find out.

Paul

7

I’ve also had this problem occasionally. Cycling the power to the Sandel has always fixed it

That strongly suggests it’s a software bug in the Sandel, not a Garmin problem.