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Products Support => GSX Support MSFS => Topic started by: Guenseli on August 20, 2022, 11:37:05 am

Title: FENIX A320 jumping on pushback end
Post by: Guenseli on August 20, 2022, 11:37:05 am
FENIX A320 is jumping once pushback has ended.
Make a loud boom sound coming from the Fenix itself. This triggers then also the landing configuration and Fenix things where where already atken off.

I unticked the Raide gear option under aircraft settings.

Wonder if anyone else has this issue ...?
And what to do against?
Title: Re: FENIX A320 jumping on pushback end
Post by: Brittanix on August 20, 2022, 11:57:55 am
Same here
Title: Re: FENIX A320 jumping on pushback end
Post by: Fiorentoni on August 20, 2022, 12:03:04 pm
I haven't tried it with the Fenix yet, but this could very well be due to the "raise gear" option, yes. This seems to trigger some unwanted stuff in the Fenix.
Title: Re: FENIX A320 jumping on pushback end
Post by: Guenseli on August 20, 2022, 12:49:29 pm
I haven't tried it with the Fenix yet, but this could very well be due to the "raise gear" option, yes. This seems to trigger some unwanted stuff in the Fenix.

But as I said, I have unticked that option. And it is not raised.
But I get the drop despite it
Title: Re: FENIX A320 jumping on pushback end
Post by: Fiorentoni on August 20, 2022, 12:55:14 pm
Ah perhaps then you should tick the option? Does it work then?
Title: Re: FENIX A320 jumping on pushback end
Post by: dreampilot on August 20, 2022, 12:58:52 pm
Ah perhaps then you should tick the option? Does it work then?
No, it's jumping as well. Although, on my single try I made this didn't cause any further problems like the plane thinking it took off, lol.
Title: Re: FENIX A320 jumping on pushback end
Post by: Fiorentoni on August 20, 2022, 01:00:36 pm
Yeah I tried and had that jump, too, when the guy removed the towbar, although it did not cause anything bad in the Fenix. Not quite sure why this is happening.
Title: Re: FENIX A320 jumping on pushback end
Post by: Barnes on August 20, 2022, 02:37:49 pm
Will add my voice here that I am also experiencing the “jump” with the Fenix A320. (With raise gear option turned off in GSX)
Title: Re: FENIX A320 jumping on pushback end
Post by: dreampilot on August 20, 2022, 03:32:42 pm
So even with towbar push it happens? I only ever seem to get the bigger pushback trucks.
Title: Re: FENIX A320 jumping on pushback end
Post by: Fiorentoni on August 20, 2022, 03:36:38 pm
So even with towbar push it happens? I only ever seem to get the bigger pushback trucks.

Yes, but for me it's only a visual bump without any effects on the aircraft systems.
Title: Re: FENIX A320 jumping on pushback end
Post by: Barnes on August 20, 2022, 03:43:40 pm
So even with towbar push it happens? I only ever seem to get the bigger pushback trucks.

Yes, I also see this with the the tow bar. I use FSRealistic, and the bump is enough to trigger the touch down sounds.
Title: Re: FENIX A320 jumping on pushback end
Post by: CosmicWanderer on August 20, 2022, 05:04:39 pm
I faced this issue only with the bigger pushback trucks. With the smaller tug I dont get any bumps.
Title: Re: FENIX A320 jumping on pushback end
Post by: Guenseli on August 20, 2022, 05:12:16 pm
I have it with all pushback trucks, small or big.
And I get it with the PMDG 737-7 also

  :-\
Title: Re: FENIX A320 jumping on pushback end
Post by: jgoggi on August 20, 2022, 05:48:57 pm
There is an effect on the Fenix instruments: the vertical speed indicator goes up to something like 80 during pushback, then goes down to a negative value.
Title: Re: FENIX A320 jumping on pushback end
Post by: disco79stu on August 20, 2022, 06:55:49 pm
Same here.
Title: Re: FENIX A320 jumping on pushback end
Post by: Bentree on August 20, 2022, 07:07:33 pm
Didn't try the Fenix with GSX Pro until now....first two days I was busy to get GSX to work in any way....but now it does, what i can say is that the PMDG B737 also jumps up after disconnecting the tug.
Title: Re: FENIX A320 jumping on pushback end
Post by: mertayd1n on August 20, 2022, 07:51:52 pm
same here. the same thing (or worse) happens with captainsim 777s. The plane is sinking into the ground.
Title: Re: FENIX A320 jumping on pushback end
Post by: ralfy124 on August 20, 2022, 07:57:43 pm
Yeah I tried and had that jump, too, when the guy removed the towbar, although it did not cause anything bad in the Fenix. Not quite sure why this is happening.

Of course it did cause bad in the Fenix, because after the jump and "touch down" on the ground, Fenix think it has landed and is not in the take off phase anymore which has been programmed in the FMC beforehand which leads to problems when taking off causing some beeps and blinks after you begin your take off role. Quite annoying while taking off.

Regards
Ralf
Title: Re: FENIX A320 jumping on pushback end
Post by: thebig_leo on August 21, 2022, 04:36:50 am
I'm having the same problem here, but before starting the push, as soon as it releases the brake. Using Citation Longitude
Title: Re: FENIX A320 jumping on pushback end
Post by: joergalv on August 21, 2022, 12:06:25 pm
The latest update has introduced those 'jumps' in the P3D version as well.
Title: Re: FENIX A320 jumping on pushback end
Post by: Artox67 on August 21, 2022, 12:11:02 pm
Yeah I tried and had that jump, too, when the guy removed the towbar, although it did not cause anything bad in the Fenix. Not quite sure why this is happening.

Of course it did cause bad in the Fenix, because after the jump and "touch down" on the ground, Fenix think it has landed and is not in the take off phase anymore which has been programmed in the FMC beforehand which leads to problems when taking off causing some beeps and blinks after you begin your take off role. Quite annoying while taking off.

Regards
Ralf
Simple workaround, do not press TO button before PB ends.

Cheers
Title: Re: FENIX A320 jumping on pushback end
Post by: Erwin06 on August 22, 2022, 09:37:04 am
Same issue, this needs to be fixed.
Title: Re: FENIX A320 jumping on pushback end
Post by: jgoggi on August 22, 2022, 09:42:21 am
Indeed, I don't know why GSX can't work like Toolbar Pushback by AmbitiousPilot in this area. That pushback smoothly raises the nose gear and smoothly lowers it at the end. With GSX there is an unnatural jump in both cases.
Title: Re: FENIX A320 jumping on pushback end
Post by: avantime on August 22, 2022, 10:29:27 am
Same on towbar tug (Fenix A320, 73.5T Gross, 27.5 CG MAC), the aircraft does a bit of a "oleo compression" with touchdown sound when towbar is disconnected.
Title: Re: FENIX A320 jumping on pushback end
Post by: hurfifx on August 22, 2022, 01:04:43 pm
Indeed, I don't know why GSX can't work like Toolbar Pushback by AmbitiousPilot in this area. That pushback smoothly raises the nose gear and smoothly lowers it at the end. With GSX there is an unnatural jump in both cases.

it doesn’t, it lift and unlift the aircraft before push (but it does it slowly so you won’t notice) and it’s lift is highly unrealistic
Title: Re: FENIX A320 jumping on pushback end
Post by: thebig_leo on August 22, 2022, 08:25:50 pm
I haven't tried it with the Fenix yet, but this could very well be due to the "raise gear" option, yes. This seems to trigger some unwanted stuff in the Fenix.

But as I said, I have unticked that option. And it is not raised.
But I get the drop despite it

Can you tell me where this tag is?
Title: Re: FENIX A320 jumping on pushback end
Post by: Fiorentoni on August 22, 2022, 08:27:35 pm
I haven't tried it with the Fenix yet, but this could very well be due to the "raise gear" option, yes. This seems to trigger some unwanted stuff in the Fenix.

But as I said, I have unticked that option. And it is not raised.
But I get the drop despite it

Can you tell me where this tag is?

GSX menu in toolbar -> airplane options (or customization? something like that)
Title: Re: FENIX A320 jumping on pushback end
Post by: pilot3033 on August 23, 2022, 12:27:39 am
Same on towbar tug (Fenix A320, 73.5T Gross, 27.5 CG MAC), the aircraft does a bit of a "oleo compression" with touchdown sound when towbar is disconnected.

I am experiencing this in the PMDG 737-700, complete with the gear sound as if I was landing.
Title: Re: FENIX A320 jumping on pushback end
Post by: Barnes on August 24, 2022, 02:02:35 pm
Hi Umberto. Any ideas on a solution to this issue ?
Title: Re: FENIX A320 jumping on pushback end
Post by: virtuali on August 24, 2022, 02:43:30 pm
Hi Umberto. Any ideas on a solution to this issue ?

There are two issues, which are not exactly the same:

- A small bump after disconnecting the towbar. This will happen regardless of the airplane, but it changes depending on the scenery, and it's due to the fact almost every airport in MSFS has some kind of elevation difference.

The way GSX pushback works, it freezes the airplane, but it doesn't disable the simulation, otherwise the airplane and the tow truck would proceed in a straight line, always at the same initial altitude MSL, because with the simulation disabled, they won't "feel" the terrain underneath. Also, disabling the simulation would disable almost all systems so, clearly, that's not an option. Instead, when the airplane is just frozen, it won't move during the pushback, so there will be no jittery due to fight between the flight model and GSX controlling it, but when the terrain changes elevation during the path, the airplane inertia system will register it so, at the end of the pushback, when it gets unfrozen, the altitude difference will catch up, causing that bump. We use some mitigation feature, like setting all the acceleration variables to 0 just before and just after unfreezing, but couldn't manage to remove it entirely. The issue is, if we didn't freeze the airplane during pushback, it you start engines, it's likely that just the movement caused by idle thrust might be enough to cause jitters, because two vectors forces would be fighting at each frame, the tow truck would likely slide as if was on ice, etc. We found that kind of bump to be a minor nuisance, compared to the alternatives.

An alternative might have been using the default Left/Right pushback events, like other default-based systems do, but that's not precise enough for what we need, since we couldn't control the position and especially the heading as finely as we can do now (small decimals of a degree), we would have a coarse Left/Right control that, since input events are processed only at 6hz, would probably always chasing the line, in addition of course to the aggravation of spamming simconnect with events, instead of setting data variables, which is way gentler to the simulation.

Having the option to raise the gear or not in Towbarless truck doesn't make any difference, once the airplane is frozen, it doesn't really matter if it's pitched up or not. We have a custom value that has been tuned manually to show just the right amount of pitch up, depending on the airplane, they don't react the same, it depends on their payload and the shockers compression value.

- Some reaction in the airplane custom systems.

That's a completely different issues, and it can be fixed completely once you'll see the first developers integrating GSX. They can detect when GSX is pushing and change any assumptions affected system about the airplane status, so it won't trigger any specific alarms.
Title: Re: FENIX A320 jumping on pushback end
Post by: Barnes on August 24, 2022, 03:03:44 pm
Hi Umberto. Any ideas on a solution to this issue ?

There are two issues, which are not exactly the same:

- A small bump after disconnecting the towbar. This will happen regardless of the airplane, but it changes depending on the scenery, and it's due to the fact almost every airport in MSFS has some kind of elevation difference.

The way GSX pushback works, it freezes the airplane, but it doesn't disable the simulation, otherwise the airplane and the tow truck would proceed in a straight line, always at the same initial altitude MSL, because with the simulation disabled, they won't "feel" the terrain underneath. Also, disabling the simulation would disable almost all systems so, clearly, that's not an option. Instead, when the airplane is just freeze, it won't move during the pushback, so there will be no jittery due to fight between the flight model and GSX controlling it, but when the terrain changes elevation during the path, the airplane inertia system will register it so, at the end of the pushback, when it gets unfrozen, the altitude difference will catch up, causing that bump. We use some mitigation feature, like setting all the accelerations variable to 0 just before and just after unfreezing, but couldn't manage to remove it entirely. The issue is, if we didn't freeze the airplane during pushback, it you start engines, it's likely that just the movement caused by idle thrust might be enough to cause jitters, because two vectors forces would be fighting at each frame, the tow truck would likely slide as if was on ice, etc. We found that kind of bump to be a minor nuisance, compared to the alternatives.

An alternative might have been using the default Left/Right pushback events, like other default-based systems do, but that's not precise enough for what we need, since we couldn't control the position and especially the heading as finely as we can do now (small decimals of a degree), we would have a coarse Left/Right control that, since input events are processed only at 6hz, would probably always chasing the line, in addition of course to the aggravation of spamming simconnect with events, instead of setting data variables, which is way gentler to the simulation.

Having the option to raise the gear or not in Towbarless truck doesn't make any difference, once the airplane is frozen, it doesn't really matter if it's pitched up or not. We have a custom value that has been tuned manually to show just the right amount of pitch up, depending on the airplane, they don't react the same, it depends on their payload and the shockers compression value.

- Some reaction in the airplane custom systems.

That's a completely different issues, and it can be fixed completely once you'll see the first developers integrating GSX. They can detect when GSX is pushing and change any assumptions affected system about the airplane status, so it won't trigger any specific alarms.

Thanks for your detailed explanation of how the pushback system in GSX works, however I also see this bump at the beginning of pushback, as well as at the end when disconnecting the towbar.
It's not really a small bump either - If I were to guess a relative height, I would say the entire aircraft (in my case the Fenix A320) is being raised about one foot at the start of push and then being dropped about the same amout when disconnecting the towbar. It's really quite a violent effect.
Title: Re: FENIX A320 jumping on pushback end
Post by: virtuali on August 24, 2022, 03:10:08 pm
It changes depending on the altitude difference in the scenery. These might be realistic or not, it really depends.

There are some sceneries we found (even default) where the parking *itself* is visibly sloped, I think pushback there wouldn't even be allowed from that position in real life, if the slope were really like that, surely a towbar would break, and I have no idea what will happen with the towbarless arms either. I guess that, at least from the parking stands to the typical pushback positions for that area, the apron should be reasonably flat, but the problem is in MSFS almost invariably isn't.
Title: Re: FENIX A320 jumping on pushback end
Post by: Guenseli on August 24, 2022, 05:12:01 pm
However,

with MSFS default pushback that does not happen ...
Whats the difference?
Title: Re: FENIX A320 jumping on pushback end
Post by: virtuali on August 24, 2022, 05:27:57 pm
with MSFS default pushback that does not happen ... Whats the difference?

The plane is not frozen, which is not required, because the default flight model *knows* the plane is being pushed.
Title: Re: FENIX A320 jumping on pushback end
Post by: AUA9085 on August 30, 2022, 08:25:02 am
Can/will this be solved sometimes?

I tried it with other Pushback tools too (Toolbar pushback for example is also raising the AC and lowering it) without this bumping effect.
Title: Re: FENIX A320 jumping on pushback end
Post by: virtuali on August 30, 2022, 10:36:06 am
Can/will this be solved sometimes? I tried it with other Pushback tools too (Toolbar pushback for example is also raising the AC and lowering it) without this bumping effect.

Have you read the previous posts ? It might be solved if we made the default pushback as an alternative way of pushing, which of course will result in less accuracy, and possibly more impact on the system.

We'll can try it, but it's not a quick "fix", and we'd rather check better ways, for example finding if there's some better solution to nullify the inertial system.
Title: Re: FENIX A320 jumping on pushback end
Post by: ycristia on September 28, 2022, 09:06:53 pm
So I guess this issue has not been solved yet? I too get the bump when pushback starts and tug disconnects.
Title: Re: FENIX A320 jumping on pushback end
Post by: rsaberi on October 30, 2022, 03:39:06 am
Every once in a while I also get a crash out of the pushback with Fenix-GSX Pro. So basically the pushback system with Fenix is useless right now. Hope you fix it.
Title: Re: FENIX A320 jumping on pushback end
Post by: virtuali on November 03, 2022, 04:11:55 pm
Every once in a while I also get a crash out of the pushback with Fenix-GSX Pro. So basically the pushback system with Fenix is useless right now. Hope you fix it.

GSX pushback works perfectly fine and it's hardly "useless". Sure, there's a minor bump, but nothing like you are describing. Have a look at these two channels:

https://www.youtube.com/c/CptCanada


They fly regularly with GSX and the Fenix, and they use GSX mostly for Pushback.
Title: Re: FENIX A320 jumping on pushback end
Post by: silvera on June 16, 2023, 04:10:54 pm
I had this issue for a long time but after using the setting "raise the nose" from aircraft options of GSX it disappeared  on pmdg 737. I no longer have jumps at the end of pushback!