GSX causing FAILURES in PMDG 737 NGXu during pushback

[Captain45]

P3Dv4.5 PMDG737NGXu GSX

At the raise before the pushback the aircraft starts to sound like there is heavy turbulence. Because I had raise issues with the QW787 too (which was a QW problem), I uncecked the box in the aircraft settings for GSX. But that was not enough. Being on the default LIRF, during the turn of the pushback, GSX sudenly stops (visually everything, including the truck is gone) and the PMDG B739 gets a FAILURE that, even when cacelled in the PMDG/AIRCRAFT/FAILURES, still freezes the plane on this position. Impossible to start taxiing. So only way out is STOP P3D and start all over again. I tried it a few times, after which I used PMDG's own pushback-truck which worked perfectly well. But... that's not why I use GSX. I had some >140 flights with the PMDG737's without any problem. Even including the raise before pushback. But since the last GSX update I'm having these issues. So my rough guess is that a bug sneaked in durig the last update.
Next to this, when on FlyTampa EHAM, which is pretty complicated, it sometimes works without any problem (raise excluded). But sometimes not. It's weird.

[virtuali]

You are referring to a problem that happened only after doing a QuickEdit pushback, which resulted in the airplane simulation disabled on exit. It has been fixed a couple of updates ago as soon it was reported.

[Captain45]

You are referring to a problem that happened only after doing a QuickEdit pushback, which resulted in the airplane simulation disabled on exit. It has been fixed a couple of updates ago as soon it was reported.

I'm sorry, but that is not the case. I did not use 'quick edit pushback' at all. Just the normal GSX pushback at LIRF gate 203 and also at several gates at FlyTampa EHAM.

[Captain45]

From the PMDG support website:
GSX locks the aircraft after pushback until the GSX tug returns to the bay before you can start moving.

And....

After the last update the new GSX PushbackRaise is causing the PMDG B737NGXu to start shaking like in extreme turbulence while standing at the gate.
When the PushbackRaise is unchecked no problems. So I'll keep the Raise of for the time being. Was never a problem before the last update.

[virtuali]

You are reporting two very different issue:

- the airplane disabled after pushback. While it only occurred after exiting the pushback, and this is surely fixed, I must say this has been tested to be fixed in MSFS only, we never tried it on FSX/P3D, so we'll check this.

- the airplane shakes if it's pushed while it's raised. This will be fixed in the next update and, again, it's a P3D-specific issue happened because we haven't fully tested it in P3D.

[Captain45]

You are reporting two very different issue:

- the airplane disabled after pushback. While it only occurred after exiting the pushback, and this is surely fixed, I must say this has been tested to be fixed in MSFS only, we never tried it on FSX/P3D, so we'll check this.

- the airplane shakes if it's pushed while it's raised. This will be fixed in the next update and, again, it's a P3D-specific issue happened because we haven't fully tested it in P3D.

Correct. If you wait long enough for the pushbacktruck to park then there is no problem. Not in P3D also.
Well... the shaking (with the PMDG737) after the raise might need some testing in P3D. It worked fine before the last update.

Thanks for sorting this out Umberto. I'll wait for the update and leave the box unchecked for a while.

[Captain45]

- the airplane disabled after pushback.

We ar not done yet on the subject of the aircraft stays locked after pushback!

OK, I know I have to wait until the tug is parked. But...
If you release the parkingbrake just after "Left is clear, right is clear" (because I check the rudder which makes P3D to release the parking brake), you get a warning to set the parkingbrake immediately. If doing so, the aircrafy stays locked, the "Have a good flight (or something)" does NOT come, and there is no way to let the aircraft start taxiing. Not even after a Couatl restart. You have to start the flight all over again, because the GSX Menu is in 'after landing mode' and you cacn only select a gate or the RWY for departure (and warp to it) which still keeps the aircraft locked in place.

May I suggest to solve this and/or unlock the aircraft after L & R are clear.

[Captain Kevin]

(because I check the rudder which makes P3D to release the parking brake)

Just to be clear, this isn't a P3D issue, but chances are, when you checked the rudder, you may have somehow tapped the brakes, which would release the parking brakes. I've never had an issue with the parking brakes being released when checking the rudder.

[Captain45]

Just to be clear, this isn't a P3D issue, but chances are, when you checked the rudder, you may have somehow tapped the brakes, which would release the parking brakes. I've never had an issue with the parking brakes being released when checking the rudder.

Correct. Never had this with the QW787, but in the PMDG 737NGXu, as soon as I touch the rudderpedals, the parkingbrake is OFF. I think I have to adjust the FSUIPC settings a bit to avoid this problem.

I installed the update that shold have solved the shaking problem after the Raise yesterday Dec. 14th. So today I cheked the box for the Raise and guess what? The problem is NOT solved. What I do notice, is that the Raise is very high. A lot higher than before this feature was implemented (2 updates ago).

[Captain Kevin]

Correct. Never had this with the QW787, but in the PMDG 737NGXu, as soon as I touch the rudderpedals, the parkingbrake is OFF. I think I have to adjust the FSUIPC settings a bit to avoid this problem.

I'd still say that's something within your settings because I fly the PMDG 737, 747, and 777, and I don't have this problem with any of them. I do have a slight null zone, so perhaps that's something you want to look into.

[virtuali]

I installed the update that shold have solved the shaking problem after the Raise yesterday Dec. 14th. So today I cheked the box for the Raise and guess what? The problem is NOT solved.

The current release notes don't say anything about the shaking problem, this is the only thing changed in the Pushback in FSX/P3D:

GSX (FSX/P3D) Fix: Airplane stuck with simulation Disabled at the end of a Pushback when using a Towbarless tug with the “Pushback Raise” option enabled in the airplane profile.

Yes, I know I said the shaking would also be fixed but I meant in general: BEFORE the update, the pushback was jumping up/down slightly with EVERY tow truck and even with the "Pushback Raise" option Disabled. Now it's always fixed UNLESS you enable the Raise option.

GSX never had any Raise option for years, we added it only recently and, while it works reasonably well with many aircraft, in P3D, I can't completely fix it with the PMDG, which does a lot of custom ground handling on its own so, with the PMDG, it's best to just Disable the Pushback Raise, which is how GSX always worked in years.

IN MSFS we don't have any issues like that with the PMDG, I guess the airplane does ground handling differently (I guess, since there's a fully sloped terrain everywhere there), but in P3D it would be best to not use Raise on the PMDG.

[Captain Kevin]

IN MSFS we don't have any issues like that with the PMDG, I guess the airplane does ground handling differently (I guess, since there's a fully sloped terrain everywhere there), but in P3D it would be best to not use Raise on the PMDG.

PMDG uses their own custom coding for the ground handling in P3D. In MSFS, they had issues with simulator updates constantly breaking their custom ground handling code, so they just use the default code for MSFS.

[Captain45]

I'd still say that's something within your settings because I fly the PMDG 737, 747, and 777, and I don't have this problem with any of them. I do have a slight null zone, so perhaps that's something you want to look into.

Hi Kevin,
After setting a null zone, it works fine most of the time. Not always. But the Logitech rudder pedal potentiometers might have got a bit sloppy through time. ;-)

Dirk

[Captain45]

in P3D it would be best to not use Raise on the PMDG.

I'll keep the box unchecked from now on. No big deal. It only surprised me that with the box checked the raise worked fine on the PMDG B737-800 until two updates ago. No issues at all until then. But thanks a lot for the explanation and all your good work Umberto.

Dirk