Post SU11 PMDG Porpoising SOLVED

[David Mills 4,733]

Many PMDG 737 owners have posted messages here and on other forums about how their 737s have been bouncing up and down during flight since the release of SU11. This visual effect can be almost sickening if you happen to be afflicted with this issue.

Earlier today, I read a comment on the PMDG forum that I dismissed at first, but soon realized was the answer to this bouncy problem. The comment warned that all pilot assistance options should be disabled in MSFS when using the PMDG 737. I didn't think I had any pilot assistance options enabled, so this couldn't possibly be the reason my 737 was continually bobbing up and down. Out of frustration I nonetheless checked under Options > Assistance Options > Piloting, and found that my AI Auto-Trim was enabled. Everything else was disabled, and I have no memory at all of enabling the AI Auto-Trim. But there it was On for some reason. I disabled the AI Auto-Trim, and the porpoising immediately ceased.

I have no idea why this problem didn't surface until SU11 nor when or why my AI Auto-Trim was erroneously enabled. It was obviously my own fault. But if you're suffering this bouncy problem with the 737, please do a double check of your pilot-assistance options, even if, like me, you're "certain" they're already off.

[fakeflyer737 991]

Hmm nice find. I'll have a look myself.

Thanks Dave 

[David Mills 4,733]

13 minutes ago, fakeflyer737 said:

Hmm nice find. I'll have a look myself.

Thanks Dave 

This may explain why many users suffered this bouncy problem, while others had no issues at all.

[KingOfLeinster 5]

Very interesting , Going to check this out 

[jarmstro 2,402]

Always worth running through your settings after an update. They seem to get reset in odd ways.

[jcomm 5,890]

Since SU9, if I correctly recall, I have a checklist whenever I enter MFS, with two items ( MFS Preparation 🙂 )

- Check options under Assiatnce ;

- Choose the correct controller configuration for my stick, HOTAS and Rudder, nbased on the aircraft I'm planning to use in the session.

 Although it is not required AFAIK, I always restart MFS when I want to change an aircraft, or make a new flight even with the same I just used. This was inherited from other versions of the simulators and addons I used in the past. I am sure MFS code is optimized enough and well designed to overcome such need, but... just in case ...

 

[ErichB 3,638]

Good find

[Rocky_53 1,566]

I have a flight out of Cologne this afternoon so I will check this specifically.

 

[DAD 2,650]

well, interesting, wanted to check my AI piloting settings as well - though having no issues with the Fenix - and see this -->

Assistance Options are set to a "Volocopter" profile and many settings are actually greyed out?! anybody else? Wonder whether the A320 is considered a volocopter nowadays 😉

[gdjak 176]

41 minutes ago, DAD said:

well, interesting, wanted to check my AI piloting settings as well - though having no issues with the Fenix - and see this -->

Assistance Options are set to a "Volocopter" profile and many settings are actually greyed out?! anybody else? Wonder whether the A320 is considered a volocopter nowadays 😉

It's an option that devs can force to disable all flight assists on their plane, I wouldn't worry about it.

[LRBS 943]

If anyone wants to have this option turned off for this particular airplane, just make an entry in flight_model.cfg under [flight_tuning] section to show  "disable_assistances=1".

I wonder why they don't have it already implemented, especially when is a known problem with their product.

 

[flight_tuning]

disable_assistances=1
                
modern_fm_only=1

Edited November 30, 2022 by LRBS

[tgsweat 144]

I have the bouncy issue at cruise sometimes and none of my assistance is on. Double checked.  I can be climbing smoothly and as soon as the plane levels out, the bouncing starts.  Same on initial decent, bouncy at cruise then as soon as the decent starts, it stops.  

[LRBS 943]

19 minutes ago, tgsweat said:

I have the bouncy issue at cruise sometimes and none of my assistance is on. Double checked.  I can be climbing smoothly and as soon as the plane levels out, the bouncing starts.  Same on initial decent, bouncy at cruise then as soon as the decent starts, it stops.  

Try this please in flight_model.cfg under

[aerodynamics]
fuselage_rigidity = -1
fuselage_inertia    = 0

[phmcr 93]

41 minutes ago, tgsweat said:

I have the bouncy issue at cruise sometimes and none of my assistance is on. Double checked.  I can be climbing smoothly and as soon as the plane levels out, the bouncing starts.  Same on initial decent, bouncy at cruise then as soon as the decent starts, it stops.  

In my case it is an unexpected bounce every once in a while and I think a weather update (abrupt pressure change) is the culprit. All the possible interfering options in the Assistance menu are off.

[Twenty6 692]

1 hour ago, LRBS said:

disable_assistances=1

 

1 hour ago, LRBS said:

fuselage_rigidity = -1
fuselage_inertia    = 0

Tried these suggestions in the Milviz 310 and it seems to have made a difference, albeit I've only done one flight. But the porpoising is no longer there  so it's a keeper.