PFD Failure Operations

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   I am a newbie to this site and this is my first post, so please bear with me if this question has been asked and answered before...
I have a Cessna 182 with avionics as follows:
- PFD is Aspen 1000 Pro
- IFD 540/440 just installed in place of Garmin units, currently set up in CrossSync mode
- GI 106A secondary nav instrument
- Honeywell KAP 140 Autopilot
- the rest of avionics doesn't really matter to my question.

The other day my instructor and I were discussing adjustment of my Standard Operating Procedures away from the Garmin approach to things and trying to adapt to the new IFD installation.  Of course there are no end of scenarios to discuss in this regard, but we started by discussing, "what if the Aspen crapped out?"

To simulate this we had a flight plan loaded and active (we were on the ground, if that matters to the question) and said OK Aspen dead/smoking/lost screen whatever the problem....power it off.

What seemed to happen was basically that the 540 (auto cross-filling/syncing to the 440) were "lost" absent having the crosstalk with the Aspen.  The GI 106A did not seem to be operating correctly or "defaulting" to become the back up nav instrument.  We then tried "failing" the IFD540 and that did seem to actually wake up the GI 106A (somewhat) but it was not seemingly operating properly in that mode either (by this point just the IFD 440 was powered up).  At this point the Autopilot becomes a brick as well, as I don't have a selector switch installed for that (which I regret).

I feel a bit dopey asking what may be a basic question, but with an Aspen failure such as I have described it is indeed the case that you are without navigation ability (other than perhaps using the course deviation capabilities within the box)?  If I had CrossSync shut off, would this solve this issue, meaning if the IFD's are operating separately...would my 106A nav instrument at least be alive and operating properly linked to the 440 at that point?

If anyone has and insights here I would be most appreciative.
Best regards,
William Taylor

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wctaylo64 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 07 Oct 2018 Location: Boston Status: Offline Points: 5	Post Options Post Reply Quote wctaylo64 Report Post Thanks(0) Quote Reply Topic: PFD Failure Operations Posted: 25 May 2019 at 12:14pm
	I am a newbie to this site and this is my first post, so please bear with me if this question has been asked and answered before... I have a Cessna 182 with avionics as follows: - PFD is Aspen 1000 Pro - IFD 540/440 just installed in place of Garmin units, currently set up in CrossSync mode - GI 106A secondary nav instrument - Honeywell KAP 140 Autopilot - the rest of avionics doesn't really matter to my question. The other day my instructor and I were discussing adjustment of my Standard Operating Procedures away from the Garmin approach to things and trying to adapt to the new IFD installation. Of course there are no end of scenarios to discuss in this regard, but we started by discussing, "what if the Aspen crapped out?" To simulate this we had a flight plan loaded and active (we were on the ground, if that matters to the question) and said OK Aspen dead/smoking/lost screen whatever the problem....power it off. What seemed to happen was basically that the 540 (auto cross-filling/syncing to the 440) were "lost" absent having the crosstalk with the Aspen. The GI 106A did not seem to be operating correctly or "defaulting" to become the back up nav instrument. We then tried "failing" the IFD540 and that did seem to actually wake up the GI 106A (somewhat) but it was not seemingly operating properly in that mode either (by this point just the IFD 440 was powered up). At this point the Autopilot becomes a brick as well, as I don't have a selector switch installed for that (which I regret). I feel a bit dopey asking what may be a basic question, but with an Aspen failure such as I have described it is indeed the case that you are without navigation ability (other than perhaps using the course deviation capabilities within the box)? If I had CrossSync shut off, would this solve this issue, meaning if the IFD's are operating separately...would my 106A nav instrument at least be alive and operating properly linked to the 440 at that point? If anyone has and insights here I would be most appreciative. Best regards, William Taylor
	Bill

paulr Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jan 2014 Status: Offline Points: 558	Post Options Post Reply Quote paulr Report Post Thanks(0) Quote Reply Posted: 25 May 2019 at 1:03pm
	Interesting question! Is the GI106A connected to the 540, the 440, or both (through some kind of switch)? I don't have an Aspen but my expectation would be that the GI106A would be completely independent of the Aspen, as it's driven by the NAV radio it's connected to. When you say "the GI 106A did not seem to be operating correctly", what do you mean? Was it flagged, or not giving valid course deviation data, or what?

wctaylo64 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 07 Oct 2018 Location: Boston Status: Offline Points: 5	Post Options Post Reply Quote wctaylo64 Report Post Thanks(0) Quote Reply Posted: 25 May 2019 at 7:22pm
	Thanks for the reply! There is no switch, so I understood it would be Nav instrument 2 hooked up to Nav/com 2 (ie the 440). Of course the 440 is also hooked up to the Aspen, so GPS2 or VLOC2 (signal coming from the 440) can be selected on the Aspen as well. By not working correctly, I would say it seems to operate correctly relative to the course selected when in GPS mode, but was erratic when the 440 was put into OBS mode. Today I tried shutting off the CrossSync thinking that may give me more insight or understanding of what is going on. The units "separated" OK but I am still not getting proper indications (in particular) relative to having the 440 in OBS mode. For example, I input a waypoint (a VOR) in GPS mode into the 440 and it drew the correct leg to that VOR from where I was (on the ground actually). The indication on the GI 106 seemed correct and GPS light was on, no flag. Then I put the 440 into OBS mode and I would expect the GI106 to allow me to draw a course then of whatever radial I dialed into the nav instrument....not so, the GI 106 stayed with GPS illuminated even though the 440 was in OBS mode, and turning the dial had no effect, still no flag. Only other thing of note I can think of is upon startup, the GI 106 goes through test mode (needles at half deflection etc) and that seems fine. Also I can say that the GI106 worked fine with the old Garmin installation (it was hooked to the G430 I had before). I will try to attach a picture from today....units not in CrossSync mode.
	Bill

chflyer Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jan 2013 Location: LSZK Status: Offline Points: 1034	Post Options Post Reply Quote chflyer Report Post Thanks(0) Quote Reply Posted: 26 May 2019 at 11:56am
	This is a good discussion. Thanks for raising it. I don't know if this is directly related, but perhaps it will give some ideas and put you on the right track. I don't have an Aspen, but do have a Sandel SN3500 EFIS, an IFD540/440 pair, and a G* GI106A. So my configuration is very similar to yours. The IFD's are set up with crossfill. I also have an old Narco 890 DME (which only has MHz/KHz output, not RS232) connected only to the IFD440. The Sandel has GPS & VLOC inputs from both IFDs via Arinc 429, and outputs GPS on 429 to both IFDs. Each IFD has its own GPS and COM antenna, but the single Nav and G/S antennae signals are provided to both IFDs. My GI106A is only connected to the IFD440, to serve as CDI for nav2. However, my avionics shop wired and configured this connection only for VLOC, not GPS, even though the GI106A is able to support GPS nav/gs input. I queried my avionics shop on this and their response was that I cannot set up my IFD440 to drive both the Sandel and 106A with GPS guidance, for an RNAV IAP as an example. The reasoning that they gave was that IFD440 outputs the GPS signals to the Sandel via Arinc 429 and the 106A requires DC signals, and the 440 cannot be configured to output GPS on the two different connection types at the same time. Perhaps an avionics specialist here can confirm that.... I am not able to judge and just believed them. I am surprised to see the 106A GPS light on in your photo so yours is clearly wired differently ..... maybe this is the problem or perhaps I got false info from my avionics shop? My expectation is similar to yours. If my Sandel 3500 fails (similar to your Aspen), I am left with only the 106A CDI as VLOC nav/gs guidance. GPS guidance could only be the lateral indicator on the IFDs, but I would lose the GS provided as part of an RNAV IAP with LPV since GPS guidance is not available on the CDI. I'll try to test your scenario on my aircraft on the ground, since I have never actually done so. Edited by chflyer - 26 May 2019 at 11:57am
	Vince

wctaylo64 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 07 Oct 2018 Location: Boston Status: Offline Points: 5	Post Options Post Reply Quote wctaylo64 Report Post Thanks(0) Quote Reply Posted: 28 May 2019 at 7:38am
	Thanks Vince for that added information. I flew yesterday and tried to further investigate what is happening here and am now more confused than ever. On the first leg, I had the units in "separated" mode and I can report proper GPS indications on the GI 106a (and also the Aspen could receive and indicate properly with GPS2). This seems to run counter to the point your Avionics installer told you? In this mode (ie separated...no cross sync), however, I still am not getting OBS course to operate or indicate properly. Also I tested the VOR's across both units and I appear to be getting improper VOR indications out of NAV2 (IFD440) and GI106a indicator. By improper I mean seriously out of sync, about 25 degrees off. This perhaps tells me I simply have something wrong with the GI 106a indicator...or is there a set up issue to calibrate this indicator (I am getting signal...just not the correct indications). I have a note in to Avidyne on this as well to my original installer but any assistance here would be most appreciated. Thank you!
	Bill

Bob H Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 26 Jan 2018 Location: NH - KMHT Status: Offline Points: 290	Post Options Post Reply Quote Bob H Report Post Thanks(0) Quote Reply Posted: 28 May 2019 at 9:14pm
	Hi Bill, I don’t think you’ve provided enough information to get a good diagnosis. If you haven’t developed a clearly defined test plan to incrementally determine what works properly and what doesn’t, I would start there. By defining settings and expected behavior prior to flying or pushing buttons in the airplane, you can more clearly determine the issue. Start with the annunciator lights. Are they behaving as expected? When you tested the VOR where it was off by 25 deg, were the VLOC annunciators on in both the GI106 and the IFD? Did you rotate the OBS through 360 degs and get the behavior expected? Did the To/From flag behave properly? It’s too easy to miss something subtle if not fully thought through, settings defined ahead of time, and all the indicators & annunciators checked that should be checked. Perhaps you did this, but just didn’t put it in your post. Also, make sure you review the IFD pilot guide to ensure you understand expected behavior. For example, your statement “…the GI 106 stayed with GPS illuminated even though the 440 was in OBS mode…” actually this is expected behavior. OBS mode is a GPS function. Based on the picture you sent, it looks to me that the IFD doesn’t recognize the GI106 OBS setting. However, the CDI looks correct for the IFD picture. What did the IFD CDI show? In OBS mode, did you try rotating the CDI knob on the IFD to see if the course and CDI changed? Lots to consider to pin it down. Edited by Bob H - 28 May 2019 at 11:04pm
	Bob

wctaylo64 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 07 Oct 2018 Location: Boston Status: Offline Points: 5	Post Options Post Reply Quote wctaylo64 Report Post Thanks(0) Quote Reply Posted: 29 May 2019 at 7:49pm
	Bob; Your suggestion is a really good one. Thank you. I did get some added information from Avidyne and it seems possible that the installing shop did not calibrate the GI106A with the Aspen "failed" and IFD #1 off, which (making some assumptions about wiring) would be a necessary step and could be part (or perhaps all) of my problem. So I need to look further into that and try that calibrating step. I am not being critical of Avidyne with this statement, but it seems to me that the advertisement of "slide in replacement" isn't really advisable at all because (depending on the installation wiring) what worked one way with the Garmin units may not translate fully with the Avidyne units. The install shop, as far as I can tell, didn't trace all the existing wiring in my plane -- rather -- they setup the IFD's based on settings they saw on the Garmin units and slid them into place. Avidyne explained to me that in at least one wiring situation, I could be getting conflicting CRS signals coming from the Aspen and the GI106A simultaneously...they described this as "not ideal". So I have some more work to do to decipher my wiring and set up, and once I figure out how it should work, develop a clear plan (per your suggestion) to test it both on the ground and in flight. Best regards. Bill
	Bill