Opinions on Sandel 3500 v. Honeywell KI-825

[peter-h]

Apart from a big price difference ($9k v. $14k according to U.S. internet pricing) are there any significant usability differences between these two?

They both seem to do the same job.

I know the Sandel uses an LCD projection system using a normal filament lamp, whereas the Honeywell seems to be a normal backlit LCD. The old 3308 was notorious for its "100 hour" lamp but the 3500 claims to have fixed that.

I know just one pilot with the KI-825 who says it is brilliant, in its usability and sunlight readability...

The aircraft panel in question is this
http://www.peter2000.co.uk/aviation/tb20-experience/tb-panel-big.jpg

and I am thinking of fitting one EHSI on the LHS (in place of the KCS-55 HSI) and another !! on the RHS (in place of the altimeter).

I would also like some bright ideas on where the 2nd altimeter might go

 

[rpadula]

Peter,

Two quick points from what I gathered looking at Sandels recently:

1. I got the impression that some very early 3500 serial numbers may have had the old bulb, or a new lighting source that hadn't quite been perfected. I believe the lighting source is now white LEDs.

2. The 3500 is 24V only.

 

[peter-h]

24V is OK with me. I too heard something LED backlight but the published part numbers don't seem to show this.

An aircraft virtually identical to mine has had the KI-825 installed

http://www.peter2000.co.uk/aviation/for-sale/m-anin.html (3rd pic down).

I've got a KX155A and a KX165A, both ILS-capable, and it would be great to have each of the two EHSIs switchable for NAV1/NAV2/GPS. Currently, my mech HSI is NAV1 or GPS.

Presumably the KI-229 RMI will become redundant if I have an EHSI next to it? The 229 is driven from NAV1/NAV2 (switchable) or the KR87 ADF.

One major advantage of a new Sandel is their software option which turns it into a horizon, although that may require their SG102 AHRS unit which is pretty new to the market.

 

[rpadula]

24V is OK with me. I too heard something LED backlight but the published part numbers don't seem to show this.

Well, it says so right on the 3500 product page:

Compact and reliable, the SN3500 Primary Navigation Display is a sunlight readable, ultra-wide-angle LED backlit display which combines advanced navigation capabilities with a full range of safety functions.​

An aircraft virtually identical to mine has had the KI-825 installed

http://www.peter2000.co.uk/aviation/for-sale/m-anin.html (3rd pic down).

Given the size of the bezel around the KI-825, I'd prefer the 3500. It looks like you get more surface area for graphics on it, and hence, a bigger DG compass animation.

I've got a KX155A and a KX165A, both ILS-capable, and it would be great to have each of the two EHSIs switchable for NAV1/NAV2/GPS. Currently, my mech HSI is NAV1 or GPS.

Presumably the KI-229 RMI will become redundant if I have an EHSI next to it? The 229 is driven from NAV1/NAV2 (switchable) or the KR87 ADF.

You could probably do that. The Sandels seemed to have a complete kitchen sink of inputs, including from ADFs.

One major advantage of a new Sandel is their software option which turns it into a horizon, although that may require their SG102 AHRS unit which is pretty new to the market.

Yep, it does. See bottom of this page. I think I've seen somewhere (can't recall right now) that they had replaced some early serial # SG102's because of problems.

One question, though: I might understand if you just wanted to drop in a replacement for your old mechanical King HSI, but at the price of a 3500 and an SG102, why not consider an Aspen?

 

[Clark1961]

One question, though: I might understand if you just wanted to drop in a replacement for your old mechanical King HSI, but at the price of a 3500 and an SG102, why not consider an Aspen?

+1

Just updated to the new Aspen software version and had a 429 bus connection to the KLN 90B added. :smile: Overall functionality is great. Still working a couple very minor details (air data --> the KLN and gpss gain) with the avionics shop and Aspen.

 

[peter-h]

I have to keep the KI-256 vac horizon a) as a backup horizon and b) to drive the KFC225 autopilot (pitch/roll voltages and flight director).

I'd very much like to get rid of the KI-256 ($11k for a new one, and they do fail) but it is complicated.

There are ways to get around this but they are a lot more work, very early days, and altogether very expensive. Aspen does not have a solution (yet). The only current bit of avionics AFAIK which is able to replace the KI-256 is a G500 with GAD43 and even then I have to have a backup horizon, which can be either vacuum or an electric one with a backup battery etc. I have collected some notes on it here, near the end where I cover various avionics upgrade options. A G500 install, with a GNS430+530 etc, would come to about $80k and I am not paying that - for zero new mission capability

I did wonder about how well tested the SG102 is in the marketplace... If this fails, you lose an awfully big chunk of your panel

Currently, I am really looking at just the Sandel 3500; nothing else. I am even keeping the KLN94 despite it not supporting RNAV SIDs/STARs. There are too many little issues involved in doing more work...

 

[John Collins]

Apart from a big price difference ($9k v. $14k according to U.S. internet pricing) are there any significant usability differences between these two?

They both seem to do the same job.

I know the Sandel uses an LCD projection system using a normal filament lamp, whereas the Honeywell seems to be a normal backlit LCD. The old 3308 was notorious for its "100 hour" lamp but the 3500 claims to have fixed that.

I know just one pilot with the KI-825 who says it is brilliant, in its usability and sunlight readability...

The aircraft panel in question is this
http://www.peter2000.co.uk/aviation/tb20-experience/tb-panel-big.jpg

and I am thinking of fitting one EHSI on the LHS (in place of the KCS-55 HSI) and another !! on the RHS (in place of the altimeter).

I would also like some bright ideas on where the 2nd altimeter might go

Peter,

Stay away from the KI825. Support is poor. It took years before it would work with WAAS here in the USA. The Sandel 3500 is a better product and is reasonably supported, but not so for the Sandel 3308.

 

[peter-h]

Thanks John... I've been speaking to some people closer to it and a) Honeywell no longer support it and b) it has a rear connector which sometimes gets disconnected in flight

Currently I am trying to find out the behaviour of the 3500 course pointer.

If you are flying towards a waypoint, exactly at what point does the course pointer flip around to the next track? Does it

1) do it *at* the waypoint

2) do it some fixed distance before the waypoint

3) do it some fixed time before the waypoint

4) do it based on a prediction based on the ground speed, angles, etc

?

Is the CP movement instant, or a gradual rotation, and if the latter how is it computed?

I am trying to work out how GPSS is going to work if the AP is driven from the EHSI, in the same way as it is currently driven from the HSI.

The other option I have is the KLN94-KFC225 direct (analog) GPSS connection. I suppose there is no harm in connecting that up anyway; it can be disabled in the KFC225 config if it doesn't work properly.

Currently, I can achieve any desired turn rate (for an intercept) by carefully turning the CP knob. There is no reason why the EHSI could not do the same i.e. implement a "GPSS" function that way. But I don't think any EHSI does that. It seems to me that in all practical EHSI installations the CP auto-rotation is totally decoupled from what the AP does.

 

[John Collins]

Peter,

I think that the Sandel 3500 has automatic slewing which will change the OBS position to the new course when the GPS displays the message to start the turn. Of course this uses ARINC 429 and you don't have it on your KLN94. To learn more about the Sandel 3500, download and study the pilots guide from their website.

Eventually you will get the brilliant idea that you should replace your KLN94 with a GNS430W or equivalent.

 

[peter-h]

On a US registered aircraft, is a 337 or a DER required for the removal of a KLN94 and KX155A and an installation of a 530W and a Sandel 3500 EHSI?

A 530 (non W) was on the original aircraft factory Type Certificate (for the right hull S/N range) but the Sandel wasn't.

I am aware of the general IFR approval route (a 337 and a flight manual supplement); I would also need BRNAV but believe this to be a self declaration as per AC90-96A.

 

[peter-h]

Just an update on this old thread...

I installed the Sandel SN3500 and it works perfectly with the KLN94.

The OBS mode implementation is particularly clean. The 3500 detects the OBS mode from a flag in the RS232 flight plan data, switches from LEG to OBS and disables course pointer auto-slew. Perfect.

I was totally unable to get this interoperability checked out pre-installation. Nobody who has ever installed one could confirm it, nobody knew. The 3500 might have done something really stupid and confusing if it incorrectly displayed the bearing of the active waypoint (like some MFDs do, if you mix manufacturers). But evidently some programmer at Sandel took care to do it just right. None of this stuff is documented or known to them.

I am writing up a detailed report on it, including turn performance under auto-slew, but without additional GPSS.