45 minutes ago, martinboehme said:

I assume the very intent of providing non-GPS and GPS versions of the same livery is so that users can avoid loading the GNS 530

It would be great if that was the case but if so why did the dev make such a strong point about leaving it out in the first place? 

It's not what you see that's the issue it's that the autopilot code running under the hood is changed when gps is made compatible. The just flight f28 USED to have only vor and they nailed it but due to overwhelming demand for consumer gps units in the plane they admitted that the vor lock and track code was compromised by allowing Asobe gps code in there. Some people in the forums pleaded to have separate install for vor only because of this and the devs said one day maybe but that was over a year ago. Their f28 has the gps in efb I think so it's livery independent but if it was THAT simple to switch between versions they could have made it that way for purchasers surely? 

I'll post links if I find them again but if you look up JUST FLIGHT FOKKER F28 VOR NAV TRACK COMPROMISED GPS UNIT AUTOPILOT or something similar there are several threads on the subject. 

Now I want to find them myself to post here for posterity! 

😉

Edit : am interested to see if page 43 has changed in manual. Do you have it? 

Edited December 22, 20241 yr by sloppysmusic

Am posting all possible relevant links here:

https://www.reddit.com/r/flightsim/s/884zZWjeGG

https://community.justflight.com/topic/5927/praise-pitch-problems-and-some-small-questions

The above is direct from horses mouth as it were! 

https://forum.pmdg.com/forum/main-forum/pmdg-dc-6-cloudmaster-forum/265552-problems-with-vor-and-gps-navigation-again/page2#post269143

Same issue affecting pmdg dc-6?

https://community.justflight.com/topic/5396/f28-enters-spirals-when-trying-to-capture-radial-vor-beam

https://community.justflight.com/topic/5107/autopilot-not-working-at-all

Hello all,

 

had the same problem and after the hint of @Hayesie i found the problem (for me):

 

When you have the PMS50 GTN750 and use the compatibility mod due to a problem with the GNS530 (https://pms50.com/msfs/wt-gns530-compatibility/), it will conflict with the autopilot of the F28, regardless if the the GNS is used or not (i fly without). The autopilot is active but won't give the commands to the plane. No headings, VORs or pitch mode.

 

After 3 days i can now finally enjoy that plane :)

 

Hope this will help some people

https://community.justflight.com/topic/5950/beam-mode-trouble-to-follow-radial

OK I think that's enough for now! Now if it was THAT simple like the f27 dual livery fix to solve this working title gps /Asobe ap problem with vor tracking why haven't the brilliant people at Just Flight managed to do it? 

I DO give credit to them admitting they had it working perfectly then compromised it for the gps. 

 

 

 

 

Edited December 22, 20241 yr by sloppysmusic

On 12/21/2024 at 9:55 AM, martinboehme said:

In other news, an update to version 1.1 was released a few days ago. Highlights are the addition of a cargo version and the ability to add a GNS 530 on top of the glareshield if desired. Full changelog:

 

I'm happy with the addition of a GPS. In Australia most VOR 'S have been removed so we rely on modern navigation. I'll try the GTNXI in standalone mode and see how that goes....

Edited December 26, 20241 yr by petejohno1

10 hours ago, petejohno1 said:

I'm happy with the addition of a GPS. In Australia most VOR 'S have been removed so we rely on modern navigation. I'll try the GTNXI in standalone mode and see how that goes....

Well yes but we already have hundreds of planes with GPS enabled. It would be nice to just have ONE ac, literally just ONE lol that is configured like it came out the factory! 

I guess my copy still is as I won't update it but if anyone knows of just ONE other airliner completely dependant on vor /adf with no gps or fms I'd love to hear about it!

I saw the 717 but that had a wna SMARTPHONE stuck up in the glareshield. Heck no. 

23 hours ago, sloppysmusic said:

I guess my copy still is as I won't update it but if anyone knows of just ONE other airliner completely dependant on vor /adf with no gps or fms I'd love to hear about it!

Until recently, I would have said the FSS 727. They've now added an FMS, but I believe it's optional and can be deactivated.

1 hour ago, martinboehme said:

Until recently, I would have said the FSS 727. They've now added an FMS, but I believe it's optional and can be deactivated.

I don't know if the FMS uses same code as standard (sub) gps? For instance the JF Ba146 uses fms and I believe does not have a gps anywhere. I've been holding off but keeping an eye on that. 

Also this optional and activate /deactivate thing. From what I've seen it just installs or removes the vc panel without adding or removing the underlying code at all. 

Coincidentally I've been doing some more reading on the f27 this morning especially the manual. The fuel trimming needs to be done by DRAGGING not just clicking on the switches, also the manual hints there is some 'secret' code in the background that links these to throttle settings during flight so changes on ground may not even show until they are appropriate. 

Also that gs thing the manual is clear that this version of ap does not have autoland so ap should be switched off at 1500ft. That's fine by me it can be used to configure the plane no problem I'm interested if trim holds after disconnecting. 

Still having huge problems with floating at idle 50ft. Even mild crosswind puts plane on grass, rudder moves but does little without a 30 degree roll too(not fun at 50 ft lol!). 

I'll experiment with higher loads first. 

Back to the vor issue. Seeing as I believe this is still a basic part of Ifr flight training in small ga planes I wonder if there are any planes at all that behave accurately? 

If I can confirm there is even just ONE plane with no gps at all I might start a new thread for that subject! 

Need do some research first and get testing on intercept and lock angles. 

Despite the overwhelming tide against it I still think it's worth putting up a fight to retain scientific accuracy in the sim especially with regard to vital (historically) navigation method. 

 

EDIT:

I've just realised that this is an ideal opportunity to test the no gps/gps situation out. It's easy to keep both versions of the F27 using backups. I can do tests now to see if there is any difference in behaviour in 3 scenarios:

1) Original VOR/ADF only no GPS plane

2) New GPS enabled ac WITHOUT GPS panel

3) New GPS enabled ac WITH CPS panel.

If there is no difference I'll be the first to reveal as well sing/dance about it. 

Will be easy to pick an airport with ILS/VOR/ADF beacons and fly test circuits.

Watch this space :D

 

Edited December 27, 20241 yr by sloppysmusic
Eureka

19 minutes ago, sloppysmusic said:

I don't know if the FMS uses same code as standard (sub) gps? For instance the JF Ba146 uses fms and I believe does not have a gps anywhere. I've been holding off but keeping an eye on that. 

Do you mean whether it uses the same code as the GNS 530? No. I believe the GNS 530 (and the issues associated with it) are unique to that simulated unit, as it overrides the internal autopilot behavior. So I would suggest you needn't be concerned about other aircraft that have an FMS.

I've done some reading of the references you sent earlier by the way, and I think I've understood what the issue is. Need to find some time to write it up.

21 minutes ago, sloppysmusic said:

Also this optional and activate /deactivate thing. From what I've seen it just installs or removes the vc panel without adding or removing the underlying code at all. 

I think that depends on the specific addon.

22 minutes ago, sloppysmusic said:

Coincidentally I've been doing some more reading on the f27 this morning especially the manual. The fuel trimming needs to be done by DRAGGING not just clicking on the switches, also the manual hints there is some 'secret' code in the background that links these to throttle settings during flight so changes on ground may not even show until they are appropriate.

I've read that bit of the manual too, and I think what it's saying is that the code is internally manipulating the throttle setting (without this showing up as a visible change in throttle position) to achieve the desired effect.

24 minutes ago, sloppysmusic said:

If I can confirm there is even just ONE plane with no gps at all I might start a new thread for that subject! 

How about the analog 172 - or if you want a (vintage) airliner, the DC-3 or Ju 52?

41 minutes ago, martinboehme said:

How about the analog 172 - or if you want a (vintage) airliner, the DC-3 or Ju 52?

Thanks for the replies, await your write up! I really wanted a late 20th century prop/jet passenger plane. Something actually QUICK!

Doesnt the analog 172 have same issue that it's just the same as the glass but with glass removed?

BTW Page 43 has been changed.

WHY did the author feel strongly enough to put it there in first place? 

NAVIGATION

No GPS is available on this panel (MSFS PS interacts too much with autopilot to give good result in this cookpit). Navigation VOR to VOR is recommended (or NDB and waypoints position which can be confirmed by VOR / NDB radials or DME).

Has been changed to

NAVIGATION

Liveries variants called "PS" have MSFS GNS530 GPS installed unlike "Classic" variants. GPS is mainly for monitoring, however autopilot will be able to follow GPS flight plan in this case: - a flight plan must be inserted in the GPS - select PS mode (in green) with PS CDI button - engage autopilot - set heading bug in order to intercept magenta track to follow with an angle not above 50 degrees - engage HD autopilot mode - engage O-APP autopilot mode Like O or LOCALIE course following, HD mode disengages when GPS flight plan track capture is active. PS track can also be followed manually in FD mode only by engaging O-APP mode with autopilot off. To use classic O or LOCALIE course following, display the LOC mode (in white) with the PS CDI button. NOTA: - as vertical navigation mode is not compatible with the age of this autopilot, NA button is not inoperative - it is possible to hide the GPS page 3 of right flight manual (the GPS will remain active)

The GPS will remain ACTIVE. I believe this is what the NON gps classic variants are. If in the classic can you click on the right panel and ADD gps? That will answer one question for sure!

EDIT : This will be good practice anyway, and I can test other ac there. Decided on EGPB Sumburgh for testing as it has ILS/LOC/VOR approaches and NDB beacon nearby (although that's irrelevant to testing this issue completely). 

Also scenic area to fly around wasting a few hours testing ✈️😉

Edited December 27, 20241 yr by sloppysmusic
EGPB test airport

9 hours ago, sloppysmusic said:

The GPS will remain ACTIVE. I believe this is what the NON gps classic variants are.

That's not how I understand it. I think this sentence refers to

• A GPS livery variant
• Where the GPS has been hidden using the "booklet" in the right-hand side pocket of the pedestal (where you can also turn failures on and off, etc.)

9 hours ago, sloppysmusic said:

If in the classic can you click on the right panel and ADD gps? That will answer one question for sure!

No, in the "classic" livery variants, the checkbox to show/hide the GPS is not even present in the pedestal "booklet". That checkbox only exists in the "GPS" livery variants.

In any case, I'm looking forward to the results of your testing. If I understand correctly, you plan to compare the following cases?

• Version 1.0
• Version 1.1, "classic" livery
• Version 1.1, GPS livery

That should be pretty insightful (and Sumburgh sounds like a great place to do it!).

One more thing: In the various discussions you linked to, people do point out that the GNS 530 should be updated to the latest version.

9 hours ago, sloppysmusic said:

BTW Page 43 has been changed.

WHY did the author feel strongly enough to put it there in first place? 

I think it's as simple as:

• He originally (for version 1.0) wasn't able to make the autopilot perform acceptably with the GNS 530 present
• Subsequently (for version 1.1), he did find a way to make the autopilot perform acceptably with the GNS 530.

Circling back now to the discussion of the issues on the F28. Of the various discussions you linked to, I found this post by Mark from Just Flight to be the most illuminating.

As I understand from what he writes, the situation is this. The GNS 530 overrides some of the autopilot logic present in the core simulator¹. Mark says he actually thinks the GNS 530 autopilot logic is better than the stock autopilot logic provided by the simulator. However, because the stock autopilot and the GNS 530 autopilot behave differently, the ideal values for the autopilot tuning parameters (that result in optimum performance) are different between the two versions of the autopilot.

In theory, he says, they could provide two separate aircraft folders, one with autopilot tuning parameters optimized for the stock autopilot, and one with those tuning parameters optimized for the GNS 530 autopilot. However, this would incur significant additional effort to develop and maintain these two sets of autopilot tuning parameters, and it's unclear whether it would even be possible to provide separate aircraft folders in the marketplace version of the addon. Instead, therefore, they've set the autopilot tuning parameters to values that provide acceptable (though probably not optimum) performance with both the stock autopilot and the GNS 530 autopilot.

There appears to be a separate issue where the autopilot fails to track VOR radials at all and instead starts flying in spirals; this is caused by having an outdated version of the GNS 530 installed. If these "spirals" are the issue you're seeing, it might be worth checking if your GNS 530 is up to date.

This, at least, is my best understanding of the situation with the F28. There's a lot of different -- and at times, it seems, contradictory -- information in those various threads.

--------

¹ Why does the Working Title GNS 530 change the autopilot behavior, given that the real-world GNS 530 unit does not contain any autopilot functionality? I can only speculate.

One possible reason may be that the deviation "needle" works differently in VOR and GPS modes: For VOR, it measures how many degrees off the desired radial you are, whereas for GPS, it measures the lateral distance (in miles) from the desired course line. However, this isn't really a convincing reason for why Working TItle would need to change the autopilot behavior, because the VOR setting is the more challenging one: The VOR needle becomes more sensitive the closer you get to the station (and one therefore needs to make sure that the autopilot doesn't over-control), while the GPS needle maintains the same sensitivity independent of the distance to the next waypoint. If the stock autopilot works well enough for VOR tracking, surely it should then work at least as well for the less challenging scenario of GPS tracking?

Another possible reason (and the more likely one in my mind) is that, when following a GPS route, the autopilot needs to make turns from one leg onto the next. This doesn't happen with VOR navigation, where one would typically select heading mode once within a few miles of the station, remain in heading mode to turn to the desired outbound radial, then re-select VOR tracking mode once established on the outbound radial. It may be that the stock autopilot logic didn't fly the turns from one leg to the next acceptably and that this necessitated the changes to the autopilot.

As I say, all of this is just speculation on my part.

By the way, I recently published a review of the F27 on the German-language flight simulation news site cruiselevel.de. Google Translate does a pretty convincing job of translating the article into English. Here's a link to the translated version:

https://cruiselevel-de.translate.goog/review-fokker-f27-von-benoit-gaurant/?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp

If this doesn't show up in English, you may need to manually select English as the destination language in the Google Translate options at the top of the page.

13 hours ago, martinboehme said:

In any case, I'm looking forward to the results of your testing. If I understand correctly, you plan to compare the following cases?

• Version 1.0
• Version 1.1, "classic" livery
• Version 1.1, GPS livery

Hey thanks for superb detailed reply and that review that I will read today when I have time to enjoy it!

Started testing at Sumburgh yesterday with v1.0 and lock-on behaved as expected but still getting some very weird landing behaviour so moved to SAWH (better scenery!) to check it wasn't just ocean winds. Am finding it literally impossible to land in this plane as at 100 feet it feels like a giant hand is shoving my plane off to one side (usually the right).

I get the same issue in FSW Lear actually. Posted couple screenshots of a go around (could not even get plane to track runway) and the first thing I saw was the actual rudder.

Wind from left, apply left rudder (right?). Screenshots show RIGHT rudder yes? Steering is fine on ground I am going to test now it's not actually reversed in flight (I use a template so would be stunned if I found out I'd been manually flying for 6 months in MSFS with reversed rudder!

Will get back with more info later. SAWH is great for testing ILS as intercept is 5100ft so radar altimeter won't work until half way down glide slope. Involves a nice turn west a few hundred feet over the mountain!

Please note in both these shots the plane is tracking parallel to runway at the time.

https://imgur.com/gallery/msfs-extreme-crosswinds-on-final-reversed-rudder-N5gxzr9

23 minutes ago, sloppysmusic said:

Wind from left, apply left rudder (right?).

A crosswind from the left should require right rudder and left aileron. (Push the nose "out of" the wind to align it with the centerline, bank into the wind so the rudder application doesn't cause the airplane to turn.)

Maybe do some initial tests with calm winds to eliminate that variable?

The scenery does look stunning - I don't fly enough in the southern hemisphere in general!

Edited December 28, 20241 yr by martinboehme

8 minutes ago, martinboehme said:

A crosswind from the left should require right rudder and left aileron. (Push the nose "out of" the wind to align it with the centerline, bank into the wind so the rudder application doesn't cause the airplane to turn.)

Maybe do some initial tests with calm winds to eliminate that variable?

The scenery does look stunning - I don't FL enough in the southern hemisphere in general!

On runway now SCBA rudder performing correctly. I think in that shot I was careening to the left so was trying to get back control.

I've been using rudder at a fairly advanced level in sims for 15 years, Mustang P51 A2A civ was great to learn. I am moving my feet entirely as I always have done its all muscle memory but something feels WRONG here. About to do test flight.

https://flightsim.to/file/55371/sawh-malvinas-argentinas-international-airport-ushuaia

 

this is scenery I used, free and beautiful spot for instrument tests! Long runway too so you can use any plane.

33 minutes ago, sloppysmusic said:

I've been using rudder at a fairly advanced level in sims for 15 years, Mustang P51 A2A civ was great to learn. I am moving my feet entirely as I always have done its all muscle memory but something feels WRONG here. About to do test flight.

I remember, as a child, asking my dad what the pedals in the car did. He needed to do some "pretend driving" before he could tell me -- it was just so instinctive. 😉

34 minutes ago, sloppysmusic said:

https://flightsim.to/file/55371/sawh-malvinas-argentinas-international-airport-ushuaia

 

this is scenery I used, free and beautiful spot for instrument tests! Long runway too so you can use any plane.

Looks great -- thanks for the pointer!

37 minutes ago, martinboehme said:

I remember, as a child, asking my dad what the pedals in the car did. He needed to do some "pretend driving" before he could tell me -- it was just so instinctive. 😉

Looks great -- thanks for the pointer!

I regularly fly up from SAWH all the way up though the Andes and finish on the US/Mexican border. There are some great freeware airports all the way on fs.to . Best thing is VOR is still very active and you can use it to fly the whole route with VOR/DME/ILS at every major airport too. 

Finished first AP lock-on test at SCBA ( the nexts stop on my Andes route!)

It has a LONG 20 mile approach with dme arc intercept so very easy to just fly north and turn slowly around for an intercept test.

The AP did its usual 'pre-lock' intercept prep turn. Then turned all the way in, not perfect. Then shortly after it did a 2nd turn to a perfect track.

This is with v1.0. I swear VOR tracking via AP in 2020 is completely fake. It behaves like a 'smart' AP system like LNAV with multiple logic decisions.

I need to research real life of course but ...as far as I know: on AP HDG mode. Fly toward say 45 degree intercept. When needle starts to move (or earlier in my test below) press VOR/LOC. When AP decides the angle is 'right' it turns ac onto track. If you going to fast it will overshoot of course and weave IRL. Except it seems to always do this with gps planes. In test below it took 3 turns to get right. Why not just one? I was flying slow and it was an easy intercept. No overshoot though. 

OK off to do the updated version now, first with gps-free livery (not sure how to do that though hmmm). Maybe I will just do the gps one first to see the 'worst' case scenario that way I will no if there is any obvious difference before splitting hairs.

https://imgur.com/gallery/fokker-27-mk500-v1-0-vor-p-lockon-test-scba-cxt6O2s