Sandel--$10,000 of Redundancy?

Not being a computer savvy tech head, I have yet to learn the true value of my Sandel SN3308. It is the least user friendly instrument in an otherwise sensational SR22 avionics suite. Aside from its obvious attributes as an HSI and RMI, can anyone expand upon the importance of the 3308, other than it being a third level redundancy map and indicator? No flames, please. I’m just a guy trying to learn how to best use my airplane.

Jeffrey: I actually agree that it’s capabilities are the most underutilized avionics in my panel (as long as you don’t count all of the timers - 2 Garmins, transponder and Davtron.)

The HSI functions quite well in IMC, especially in the approach phase. But I have yet to come up with the best “setup” for the map. Ideally, I’d like to see all approach segments, the missed, all waypoints, fixes, etc., and all navigation sources, and nothing else.

In reality, I find it’s single most useful function is to show the Stormscope at 200 NMs while the ARNAV shows 25 - 100 NMs. This keep my wife’s attention and anxieties off the storms that are 200 miles in front and 30 NM off course. While they need to be considered, they are not an urgent issue.

I too would like to hear from folks describing how they set it up and use it.


I think the Sandel was originally designed to be a new twist on the old Airgus moving map which was a monochrome mini MFD designed several years ago.
The Sandel takes the technology a step beyond with color and a combination HSI and moving map.
But in our Cirri, with the Avidyne/ARNAV, many of the features of the Sandel are redundant and the display is bigger and better on the MFD. Therefore, I have found most of the map features of the Sandel to be not that useful to me as I have a much better presentation on the “big screen” which also gives better total situiational awareness than the little screen on the Sandel.
But I very much like the color HSI and the bearing pointers which allow all nav inputs to basically seen together on one screen. If the moving map were to die, the data depicted on the Sandel would be easy to follow as a backup.

In cruise, I generally set-up the Sandel to show my route and all airports in 360 view, with the range set to my glide distance from my altitude. That way if I have an engine failure, I can turn to the nearest field without interrupting my scan or pushing any buttons.


The auto-slew feature works so well that I almost always forget to “twist” number 2 CDI until the Garmin sends me a message. 5 T’s became 4 T’s.

And an excellent CPPP seminar topic!


Having thought about it, I do have a few tips for beginners:

I hit the “Sync” button frequently to keep the heading bug on the current heading with the wind correction already set. That way, if I want or need to stick fly, I already know the proper heading. Also, if I need to adjust the A/P, I will usually hit “HDG” which will keep the plane on its current course, then adjust the Garmin’s and verify the new course before hitting “Nav” “Nav” again.

I I stick fly, except for approaches when I would actually use the map features, I use the Arc View, because the heading bug is bigger and easier to keep centered.


For me the Sandel is my favorite instrument. While the MFD is larger it isn’t in my normal scan pattern. I set the Sandel up in arc mode (for almost everything), and display my course, waypoints and airports. I usually keep it on the 30-50 mile range enroute and zoom in for terminal operations. What I like is that everything I want to see (distance to next waypoint, GS, course line, next course line, and any stormscope activity) is right in front of me and is part of my scan.
On non precision approaches (and some ILS that use crossing radials for reference) I use the RMI function so again everything is on one instrument.
There is no question that all of us have favorite techniques and I understand how the Sandel can seem redundant, but for me it makes flying much easier and more precise.
If you only use it as an electronic HSI with the standard HSI presentation I agree it’s no better than a non electric HSI (although it seems to be far more reliable).

I agree. Would hate to fly without it now.

Some of the major factors:

  1. Color coding of source input. You can easily tell if the HSI is being driven by the GPS or the VOR/ILS.
  2. A/B Displays. I keep the A side displaying ALL data. VORs, NDBs, airspace, airports, etc. The B side is the plain HSI CDIs.

This is very helpful for me, as I keep the display on the map for my enroute leg. As I approach the instrument approach, I move to the second Map display which displays only airports and my waypoints (which include my approach). This effectively declutters the display. I also will usually zoom into 15 miles or so. This gives me unprecedented situational awareness at the most critical time – right in my scan.

Right before Intercept, I’ll push the A/B switch and switch to the full HSI screen where my needles are. I can easily switch to the map again with a single button press to see upcoming waypoints or leave it on the HSI display for the approach.

  1. Autoslew. This is almost worth the price of admission alone. The Sandel will automatically change the OBS for your next course and next waypoint. This is excellent with GPSS autopilot operations as well.

  2. Great Autopilot coordination. The Sandel can drive your autopilot. But adding GPSS and the Sandel really make for easy flying. With Autoslew and GPSS, your autopilot flies your flightplan and your Sandel always shows it correctly. Without user interaction. Great way to reduce stress when you may need it.

  3. Arc view. You can see the display as an ARC as opposed to the full 360 compass. I personally don’t prefer the ARC view for most of my flying, but for many it’s an advantage.

  4. Stormscope Data right on the screen. You can see your stormscope information at a different zoom compared to your MFD and you can have one on Strike and the other on Cell.

  5. Everything right in front. Including the Garmin Message Indicator (which I use to remind me to switch tanks), and Marker lights, speed, heading, track, waypoint, etc.

  6. RMI presentation (but on mine it won’t display GPS 2 as a pointer, but I understand this can be fixed with a software upgrade.

I’m sure I can come up with other advantages.

Derek Rowan

Speaking of operating tips, there is good stuff at