Oscillating in flight

[Andy245]

Hi all

Just lately (last 3 or 4 flights) I am having this recurring problem where the aircraft starts oscillating today it seemed to be pitch only but in past flights pitch and roll. This continues to get worse until the autopilot kicks out. The weird thing is if I disconnect the AP the aircraft immediately calms down and I can hand fly with thumb and forefinger. Sometimes the problem will disappear and I think its sorted then later in the flight it returns I have tried no weather and I have taken out any curves in my yoke. I'm not sure what else it could be. I dare not do a long flight because I cant trust it to fly without being monitored.

(And I wish the cleaners would be more careful when dusting the circuit breakers lol)

[Pils]

Are you on a Mac?

[Andy245]

no windows

 

[Andy245]

I may have an answer. Did a flight today and placed a frame rate counter (something I don't normally watch). My setup is not a high end system probably not even mid range. It seems to be happening when the frame rate drops very low (I'm not going to give it a number, because it's embarrassing) 

So later today I'll re-instal the Challenger in 4k and watch some you tube videos on graphics settings and do another flight to see if there is any improvement.

[Pils]

Yes, the sim needs to run at a minimum frame rate for the physics and mathematical calculations to run properly; X-Plane itself needs at least 20 FPS.

You can also consult: 

 

[mtmurat]

I have noticed this too. As mentioned in a previous post- saved scenarios (in-flight) often breed weird behavior like this. Especially if it’s been a few days since you launched the scenario.

Oft problems like this include:

FMS loses all Perf Init and Flight Plans

PFDs and MFDs all black (but you can pop them out and this work fine)

TAT on PFDs is dashed out yellow

Oscillations in pitch that an dynamically unstable- often unrecoverable.

All VNAV becomes unusable.

I use three machines/ three copies of XP12 and CL650:

I7 9700K, 4070 Ti Super homebuilt

ASUS I9/ 4070 Super gaming laptop

MacBook Pro M4

On a positive note- starting from cold dark airplane seems to always work fine. This is exactly like the real airplane, so I’m not bothered by it.