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Installing 2nd EHSI on RHS - Major or Minor (N-reg)?

I already have a Sandel SN3500 EHSI in the LHS, which was done as a somewhat complicated Major Alteration project.

It is quite difficult to do that sort of thing now, on a European based N-reg, without a contact in the USA who can sit down with an FSDO inspector out there and process the paperwork.

I now want to install another SN3500 in the RHS.

Normally, from what I have seen, provided the RHS EHSI cannot "control" anything in the plane, it is done as a Minor Alteration.

I'd be happy with that level of functionality i.e. it can display loads of stuff e.g. GPS, NAV1, NAV2, DME, TCAS, stormscope, etc.

Are there any factors which would make it a Major Alteration?

Is an AFMS needed for the RHS EHSI? Ex-Socata, I don't have an AFMS for most of the RHS stuff anyway.

Would installing a toggle switch which enables the autopilot to work off the heading bug (in HDG mode) of either EHSI make it a Major Alteration?

Shoreham EGKA, United Kingdom

Have I mentioned that you're doing absolutely the wrong thing here? Investing in a Sandel in 2013 is like buying a Nokia 2110 today (although the Nokia sells for 10 € nowadays).

Move the Sandel to the RHS and get an Aspen for the LHS or -- if you want to spend more -- a G500. This will greatly improve functionality and redundancy.

I guess I have mentioned that before

I guess I have mentioned that before

You have, and I told you what I think of Aspen. If I posted photos I got from colleague(s) showing a big cross across the EFD1000 screen, they might not appreciate it when they come to sell their plane

I like the build quality of the SN3500 and its fantastic display - especially now that the ruggedised and formerly pricey helicopter version pops up on the used market for about 3k.

Shoreham EGKA, United Kingdom

Seems that Peter is not the only one who is a big fan of the Sandel SN3500:


That Yahoo forum is not accessible openly. One has to set up a Yahoo ID and join up...

Sandel products are hanging in there because they are rugged and used by the helicopter crowd, and the military. That's also why they are not exactly cheap - a "discount" SN3500 is $9k now (Gulf Coast Aero is one of several advertisers).

Also the display quality / sunlight readability totally wipes the floor with everything I have ever seen.

It's a great product functionally too. In the Master mode, you bring everything into it and it acts as your "NAV/GPS" relay, saving a huge amount of wiring, at least two of these 8-pole or 12-pole relays

and then you can have anything up to GPS1 GPS2 NAV1 NAV2 (and some oddball stuff like Loran I think) all selectable and all capable of driving the autopilot which then connects to the Sandel's FCS output. The autopilot is driven in both lateral and vertical modes so anything that gives you VNAV will "just work" (GPS or ILS in reality). The 2xGPS and 2xNAV (or even 2xGPS and 1xNAV) selection functionality would conventionally result in so much wiring you would need to do a new W&B

In the LHS I didn't do the Master mode, because I wanted to preserve the KI525 reinstall option, but when I do the RHS one I will not be controlling anything in the aircraft (it will be a display device only) so there is no downside.

Currently I am trying to buy some used Sandel stuff, which will go to Sandel for a refurb. Only Sandel can issue an 8130-3 for their stuff ($500).

Shoreham EGKA, United Kingdom
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