TBM 900 Autopilot Issue with Nav button

[gscottfuller]

The Nav button in the Autopilot will not engage until some form of altitude function (VS or FLC) has been selected first. So you could be hand flying and desire to have the AP takeover and navigate to the next waypoint in the flight plan but Nav will not engage whether or not you've already pressed AP. The light flashes when you press the button, but then goes off the second you let off on the button. However, if you engage VS or FLC and then select Nav, it will engage. Don't have this issue with other X-Plane planes. Please advise on how to correct this. Thanks.

[gscottfuller]

The issue of the intermittent failure of the NAV button in the AP has gotten worse. Today while in flight, I could not get the NAV button to arm at all so could not fly an ILS approach using AP to the destination airport. I am not running any plug-ins in X-Plane and do not have this problem with other planes. Any ideas how to troubleshoot?

[Goran_M]

The ILS bug is something we've been aware of for a while.  It's fixed for the next update.  In the meantime, reverting back to X-Plane 11 navdata (not 11.50) will fix this for you.

[CJSouthern]

For what it's worth, I've been "getting to know" the G1000 & AP systems for a few days now - and have discovered quite a few "gotchas"; I'm assuming that most are correct G1000 / AP behaviour but as I don't have any experience with G1000 IRL I can't say for sure.

Some of the following might (or might not!) help.

1. You need to turn on the Flight Director by pressing the FD button before you can select a lateral navigation mode.

2. You need to turn ALT on before pre-selecting an altitude; if you do it the other way around it'll change whatever you've entered to whatever altitude the aircraft is currently at.

3. If you don't engage the AP quickly enough you can get a situation where the aircraft is "out of position" relative to the waypoint you wanted to track to and when you do engage it it won't track to ANY waypoint. From there it can be a real wrestling match; usually highlighting the waypoint and selecting "activate leg" won't work - sometimes it's possible to get it to work by using Direct To (or just activating a waypoint further down the list). Sometimes it just won't steer the aircraft in NAV mode no matter what I do; at that point all I can do is use HDG mode. Some times I'm able to get it working again, but I'm really not sure what the "secret sauce" is (I think it's not only a combination of "what I do" but also "where the aircraft is relative to waypoints" as well).

4. If you have an enroute phase entered - and you have an approach phase entered (but not activated) - but you don't have an arrival entered - it won't track from the last enroute waypoint to the first approach waypoint unless you activate the approach - even though the waypoints are listed in sequence. You HAVE to activate the approach or it'll just say "arriving at waypoint" and then carry on past it.

5. Vertical nav has a 5 min timeout. If you arm it more than 5 min before top of descent it'll just dis-arm after 5 min.

6. Vertical nav doesn't navigate to a final approach fix altitude.

7. Vertical nav still respects selected altitude - so this needs to be set lower than (or equal to) the VNAV altitude or that's where it'll level off (or more likely the reason why it won't start to descend)

8. Altitudes next to waypoints are for "information only" if they're in white (white "sheds light" on the situation). If you want the VNAV to act on them then you have to select them and press enter to turn them blue. If they're in small blue then they're "per the database" - if they're in large blue font then that's something you've over-ridden the database with.

9. VNAV sometimes just blatantly refuses to control the aircraft - seems to happen when I'm "slightly behind the aircraft" and forget to set something correctly prior to TOD; from that point all I can do it use VS to get the aircraft going down using guideance from the VNAV section on the MFD.

Hope this helps someone ... and in return if those who know more about it than me can help me understand where I'm going wrong that would also be greatly appreciated.

[gscottfuller]

Thanks CJ for these observations. I'll check them out on my next TBM outing. Some of the items you describe have not been an issue in other planes but if they help with the TBM, that's great.

[CJSouthern]

2 hours ago, gscottfuller said:

Thanks CJ for these observations. I'll check them out on my next TBM outing. Some of the items you describe have not been an issue in other planes but if they help with the TBM, that's great.

No worries. In my case I'm pretty sure that 90% of the problem is the part between the yoke and the seat!

[gscottfuller]

On 12/13/2020 at 4:50 PM, Goran_M said:

The ILS bug is something we've been aware of for a while.  It's fixed for the next update.  In the meantime, reverting back to X-Plane 11 navdata (not 11.50) will fix this for you.

Not sure what you mean by reverting back to X-Plane 11 navdata. I'm running the latest version of X-Plane 11 and I regularly update the GPS data from the FAA on the AIRAC cycles. Should I be doing something different for the Hotstart TBM? Thanks.

[Goran_M]

There is X-Plane 11 navdata and X-Plane 11.50 navdata.  Something changed in the X-Plane 11.50 navdata that is causing the ILS problem in the TBM.

[gscottfuller]

Is there an ETA on the next Hotstart update that will remedy the "navdata" issue? And if it's not soon, should I revert to the older version of X-Plane in order to fly the TBM with ILS working? By "navdata", I assume we are talking about something in the X-Plane software code, not the AIRAC data for the GPS, correct?

Thanks.

[Goran_M]

No ETA, but we're currently on beta 8, with over 200 testers helping out.  The ILS problem is currently fixed for the beta, but there were other problems that needed addressing.

[gscottfuller]

On 12/13/2020 at 5:55 PM, CJSouthern said:

For what it's worth, I've been "getting to know" the G1000 & AP systems for a few days now - and have discovered quite a few "gotchas"; I'm assuming that most are correct G1000 / AP behaviour but as I don't have any experience with G1000 IRL I can't say for sure.

Some of the following might (or might not!) help.

1. You need to turn on the Flight Director by pressing the FD button before you can select a lateral navigation mode.

2. You need to turn ALT on before pre-selecting an altitude; if you do it the other way around it'll change whatever you've entered to whatever altitude the aircraft is currently at.

3. If you don't engage the AP quickly enough you can get a situation where the aircraft is "out of position" relative to the waypoint you wanted to track to and when you do engage it it won't track to ANY waypoint. From there it can be a real wrestling match; usually highlighting the waypoint and selecting "activate leg" won't work - sometimes it's possible to get it to work by using Direct To (or just activating a waypoint further down the list). Sometimes it just won't steer the aircraft in NAV mode no matter what I do; at that point all I can do is use HDG mode. Some times I'm able to get it working again, but I'm really not sure what the "secret sauce" is (I think it's not only a combination of "what I do" but also "where the aircraft is relative to waypoints" as well).

4. If you have an enroute phase entered - and you have an approach phase entered (but not activated) - but you don't have an arrival entered - it won't track from the last enroute waypoint to the first approach waypoint unless you activate the approach - even though the waypoints are listed in sequence. You HAVE to activate the approach or it'll just say "arriving at waypoint" and then carry on past it.

5. Vertical nav has a 5 min timeout. If you arm it more than 5 min before top of descent it'll just dis-arm after 5 min.

6. Vertical nav doesn't navigate to a final approach fix altitude.

7. Vertical nav still respects selected altitude - so this needs to be set lower than (or equal to) the VNAV altitude or that's where it'll level off (or more likely the reason why it won't start to descend)

8. Altitudes next to waypoints are for "information only" if they're in white (white "sheds light" on the situation). If you want the VNAV to act on them then you have to select them and press enter to turn them blue. If they're in small blue then they're "per the database" - if they're in large blue font then that's something you've over-ridden the database with.

9. VNAV sometimes just blatantly refuses to control the aircraft - seems to happen when I'm "slightly behind the aircraft" and forget to set something correctly prior to TOD; from that point all I can do it use VS to get the aircraft going down using guideance from the VNAV section on the MFD.

Hope this helps someone ... and in return if those who know more about it than me can help me understand where I'm going wrong that would also be greatly appreciated.

CJ - Your observation about engaging FD before a lateral AP mode has consistently worked now through several flights -- thank you. If I engage FD, it then allows me to engage NAV which previously I could not do. But it's worth noting, that's not the same as all other X-Plane planes I've flown. All but the TBM allow you to arm NAV or FLC on the ground without having the FD on. Once in the air, engaging AP will then activate NAV, HDG, FLC or VS. So I'm not sure why the TBM was set up to require FD before arming lateral and vertical modes. I have not tried your VNAV suggestions yet as I have not been using SIDs and STARs lately where VNAV becomes more relevant. Thanks.

[CJSouthern]

Excellent news. To be honest, I have no idea what the actual G1000 in a TBM requires in terms of "FD before arming anything else"; I always fly with the FD on so it's not a biggie for me either way.

I've also found that vertical nav requires you to "keep ahead of it"; if you try to engage it (or lower the selected altitude) after it should already have kicked in then you're out of luck. Not 100% sure of the exact behaviour - will learn more over the Christmas break.

[armstrongm1000]

As Navigraph have recently stated that the  Airac cycle 2014 will be the last for Xplane 11.41 and will no longer be supported, I hope that X Aviation will release an update for the HotStart TBM 900 Locolizer fault Very very Soon. Users have been waiting for the update for an excessive amount of time.

[Goran_M]

With all due respect, we're aware of the new AIRAC cycle.  

And there is no gauge for an "excessive" amount of time.  Especially with 200+ testers.

We're working on it as hard as we can.  Remember, it was Navigraph who made the changes we need to make fixes for.  Not the other way around.  I sometimes wonder if anyone has complained to Navigraph for what they have done.

Edited January 1, 2021 by Goran_M

[armstrongm1000]

I Purchased the TBM in early October I would consider 3 Months to be an excessive amount of time to wait for the fix, however I understand your comment with regard to Navigraph and XPlane 11.41 and update to  11.50, but with respect your website does not state the incompatibility with XPlane 11.50 at the time of purchase. I want to purchase more of XAviation products but I would like to have confidence that the product support team are sympathetic to the purchasers concerns with regards to fixing known issues in a reasonable timeframe.

[Goran_M]

We appreciate every single customer who purchases the TBM, or anything else either myself or Saso has been involved in, but updates can take a week, a month or even a year.  It all depends on what is involved, and in this case, the only thing holding us back, is Vulkan and its interaction with the rain effects.  And that is, somewhat understandable, seeing as Vulkan still has some bugs in it.  The ILS is fixed, and it has been fixed for quite a while.  It was one of, if not THE first thing to get fixed for this update.  

As soon as the rain and ice effects get fixed, the update will be considered finished, and will be added to the store.  

On a somewhat similar note, I sometimes go back to the example of PMDG taking 18 months to come out with an update to their 737NG, for an obsolete sim, that was nowhere near as complex as X-Plane.  Keeping in mind, they had a team of 14 developers when that was being done.  

I can understand the frustration you, and many others have, but we are equally, if not more frustrated at the inconsistent reports from testers on why the ice and rain effects are working on some systems, but not others.  It's not an easy issue to pin down, and several builds have already been shipped to the testers over the last few months.

Hopefully, it won't be much longer.

 

Edited January 1, 2021 by Goran_M

[armstrongm1000]

Hi Goran thank you for the reply I understand your frustration, and I will await  the update to the TBM hopefully we can get a Localizer fix before the Airac 2014 cycle is out of date thanks again for your response.

[CJSouthern]

9 hours ago, Goran_M said:

With all due respect, we're aware of the new AIRAC cycle.  

And there is no gauge for an "excessive" amount of time.  Especially with 200+ testers.

We're working on it as hard as we can.  Remember, it was Navigraph who made the changes we need to make fixes for.  Not the other way around.  I sometimes wonder if anyone has complained to Navigraph for what they have done.

For what it's worth, I flew the beta last night and the rain effects looked great (RTX 3080 based system, no addons).

Also for what it's worth, I have mixed experiences with NaviGraph; I've had some great support on a couple of issues but was very surprised to discover that their Navigraph Charts product doesn't include altimetry for enroute phases which is "kinda important" for IFR flight planning.

[Ftrdoc]

Just purchased this superb model and love flying it. Was wondering though  is anyone still having issues with intermittent failure of NAV function engagement in TBM AP. Seems now the only way to engage NAV  is to cycle CDI from GPS to VLOC to GPS and then reselect NAV. Every other function works perfectly. Terrific model but since most of my flying is IFR this has become sort of a nonstarter. Would appreciate any suggestions.