Random Pitch Ups During Level Flight

[Electr0 0]

Hi All,

 

I've been having some major problems with both the CRJ 700 and 900 lately.

 

I'll be in level flight with the autopilot engaged following a flight plan, and the plane will randomly pitch up suddenly, by about 10-15 degrees.

The autopilot then corrects it and level flight will resume. A random amount of time later, it will occur again and again and again...

 

I have checked for spoiler deployment, and that doesn't seem to be an issue.

I have used the default weights in the EFB, only modifying fuel, and it's still an issue.

I have pressed the "Set Payload In Simulator" twice and it's still an issue

I have checked for random contoller inputs, and there are none.

I am using "Modern" flight controls.

I have set the Empty CG Position to 35.00 as per the user manual. The manual says the "slider needs to be fully right", however this corresponds to a Empty CG 56.00. It appears that the user manual requires updating.

 

I have no idea what to do, and all the somewhat related topics are from back in 2021.

 

Any ideas what is going on?

@Aerosoft Team@SimWare

 

Edit: I performed a quick flight from "Ready to Taxi" with the Empty CG set to 35.00, I did not adjust anything on the EFB, I did not press "Set Payload in Simulator", and did not modify the fuel. In the short time I flew at FL220 (about 10 minutes) I didn't experience any issues.

This has me thinking that it's an issue with the Weights and Balance, specifically modifying the fuel which modifies the payload.

 

 

[Electr0 0]

Anyone?

[Mathijs Kok 136]

I'm sorry you did not have a reply yet Electr0.  As I used to be the Project Manager for this project (before leaving Aerosoft), perhaps I can assist.

 

First of all, I have never seen this issue before. That's important information because that means you must look at an issue specific to your machine and not something problematic in the software. The module that sets the weight is only used when the data is sent to the simulator and does not run after that, so the chance that's an issue seems very small.

 

Much more likely is a control input issue. This is a very common problem in the sim, the bane of any support department. It's easy to check, make a 100% empty control assignment file, and start with adding only the absolute minimal assignments.
 

[Electr0 0]

Hey Mathijs, thanks very much for the reply!

 

I had some extra time the past couple of days and did an additional 2 test flights.

This time I used the Zero Fuel Weight page in the EFB to set the weights and balances, instead of setting the Fuel, Passenges and Cargo in the alternative screen.

So far I haven't had this issue. I'll keeps testing and if it occurs and will also try out your solution.

 

However I did seem to encounter this issue when flying a missed approach yesterday, when engagin the autopilot.

As noted there, when activating Autopilot the trim snaps back to the last used trim value while autopilot was on, instead of using/starting at the already manually set value before autopilot is engaged.

[Mathijs Kok 136]

That 2021 issue was addressed with an update. 

 

Still sounds very much like something in the sim interacting. You do not have the silly build in assists activated?

 

Mathijs Kok

PMDG Simulations

[SimWare 731]

As a complement to Mathijs post here above, you may want to check this :