twitching in flight
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Hey there,
Wondered if anyone else had issues where the aircraft will be flying normally, then suddenly small but abrupt twitches occur with the horizontal stabilizer? seems like some kind of issue with the flight model or something because it happens regularly but honestly say i don't think i've ever experienced this when flying the pa28 in real life... it does this across all the pa28 line too. hope someone could help me on this
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Hey there,
Wondered if anyone else had issues where the aircraft will be flying normally, then suddenly small but abrupt twitches occur with the horizontal stabilizer? seems like some kind of issue with the flight model or something because it happens regularly but honestly say i don't think i've ever experienced this when flying the pa28 in real life... it does this across all the pa28 line too. hope someone could help me on this
@wpa12 sounds like it could be a hardware problem. I had a twitching issue in the ailerons before and it turned out my yoke's sensors had gotten a bit dirty. Do you actually see the elevator twitching up and down?
You can check this by going to the sensitivity settings in the controls settings, it will show a dot on the input/output curve and if that is twitchy, it means it's a hardware issue
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@wpa12 sounds like it could be a hardware problem. I had a twitching issue in the ailerons before and it turned out my yoke's sensors had gotten a bit dirty. Do you actually see the elevator twitching up and down?
You can check this by going to the sensitivity settings in the controls settings, it will show a dot on the input/output curve and if that is twitchy, it means it's a hardware issue
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@n293wk it's old problem that have all Pipers:
https://community.justflight.com/topic/2683/pitch-jerks/65
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@sebastianr The OP mentioned the elevator was twitching. This sim has no force feedback, so the only thing that would cause that is an input causing it to twitch.
@n293wk Apologies, @SebastianR is correct, i didn't articulate the issue correctly, but what i meant was a twitching with is occurring at the horizontal stabiliser, i.e. like a random heavy lifting force being applied only to the HS of the aircraft causing a random oscillation/nose pitching down and up again, only slight... but enough to be that little bit annoying, usually happens when a wind is applied but i have see it happen in non-windy/gusty conditions too. just wondered if anyone figured out what iss causing this and if there was a potential fix that can be applied or is in the process of being applied by JF- but i can see that JF are looking to release an update to fix this so that's good, i'll close this. thanks guys
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@n293wk Apologies, @SebastianR is correct, i didn't articulate the issue correctly, but what i meant was a twitching with is occurring at the horizontal stabiliser, i.e. like a random heavy lifting force being applied only to the HS of the aircraft causing a random oscillation/nose pitching down and up again, only slight... but enough to be that little bit annoying, usually happens when a wind is applied but i have see it happen in non-windy/gusty conditions too. just wondered if anyone figured out what iss causing this and if there was a potential fix that can be applied or is in the process of being applied by JF- but i can see that JF are looking to release an update to fix this so that's good, i'll close this. thanks guys
@wpa12 does it look like what is happening here on this flight?
https://youtu.be/DTl7Y-fPSfE
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@wpa12 does it look like what is happening here on this flight?
https://youtu.be/DTl7Y-fPSfE
@cgnoorloos this is exactly what i'm talking about... actually makes the thing completely unenjoyable to fly which is a shame as this is the plane i fly in real life. i hope JF just come out and fix this sort of issue personally as it kills the experience massively. would actually be good to see them implement soft-body and prop effects too
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@cgnoorloos this is exactly what i'm talking about... actually makes the thing completely unenjoyable to fly which is a shame as this is the plane i fly in real life. i hope JF just come out and fix this sort of issue personally as it kills the experience massively. would actually be good to see them implement soft-body and prop effects too
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Yep - exact same thing here. I own a PA-28 in real life and it flies a lot smoother than this! I thought maybe it was weather related but "clear" Wx does the same thing. I thought maybe it was my cameras or yoke sensitivity. Negative.
It would be nice to eliminate that twitch because it is annoying and not like anything I experience in the real world outside of choppy turbulence.
Benjamin
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Can someone check to see if this improves their experience with the pitch jerks. I'm not sure if I'm getting a placebo effect, but I think changing the following seems to help. I would be interested to hear @Delta558 thoughts?
(I'm not a dev, just someone desperate to get their beloved Warrior back)
In the flight_model.cfg there is this entry:
empty_weight_pitch_MOI =688.700012I looked through other single engine flight models and this figure always seems to be much higher, sometimes as high as ~7000.
I changed the field to
empty_weight_pitch_MOI =3688.700012and I did some circuits on a breezy day hotswapping between the two figures and I think it feels better. Again I'm not an aircraft dev in any way whatsoever, so it could be (detrimentally) changing something else with the flight model. The bird still pitches but it's not the jarring type that we are currently getting.Will be interested to see if I'm being a moron and imagining this...
For clarification here is the descriptor for MOI:
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Can someone check to see if this improves their experience with the pitch jerks. I'm not sure if I'm getting a placebo effect, but I think changing the following seems to help. I would be interested to hear @Delta558 thoughts?
(I'm not a dev, just someone desperate to get their beloved Warrior back)
In the flight_model.cfg there is this entry:
empty_weight_pitch_MOI =688.700012I looked through other single engine flight models and this figure always seems to be much higher, sometimes as high as ~7000.
I changed the field to
empty_weight_pitch_MOI =3688.700012and I did some circuits on a breezy day hotswapping between the two figures and I think it feels better. Again I'm not an aircraft dev in any way whatsoever, so it could be (detrimentally) changing something else with the flight model. The bird still pitches but it's not the jarring type that we are currently getting.Will be interested to see if I'm being a moron and imagining this...
For clarification here is the descriptor for MOI:
The MOIs have been a source of confusion with this game - Roskam's paper 'Airplane Flight Dynamics and Automatic Flight Controls Part I' gives many calculated coefficients including MOIs for various 'typical aircraft' in the appendix. The nearest to the Pipers is a C172:
(From top: Pitch, Roll, Yaw, coupled).
The figures in the PA28 release were calculated using a tool which is based on his work, and in all previous sims worked well. My current MOI setting for the PA28s, based on the fact that MSFS does not follow aerodynamic conventions, has basically added 2000 to each MOI and as far as I can see, the twitch is still present and the 'feel' has been detrimentally affected. The fact that the Pitts has a pitch MOI of 527, the CAP10c 905, the C172 is at 2000 (note the last is more than double Roskam's calculated figure), suggests that the problem does not lie there. IF altering it to a non-realistic value were to solve the problem, then I would say it is simply masking a problem elsewhere. As I have noted before, using the forces debug tool I am seeing a rapid and continuous reversal of force on the horizontal tail from upwards to downwards at a frequency which appears to tie in with the twitch. It's a shame that so much of the core flight model is still undocumented and in many respects aerodynamically illogical because it leaves us reliant on others (Asobo) to solve this sort of issue. They built it, they strayed from aerodynamic principles (which FSX / P3D were firmly rooted in), they have given us a massive headache trying to deal with this sort of issue which should be a quick fix but instead leaves all the people that have looked at this scratching their heads and playing guessing games. Multiple people have looked at this on our side, nobody has succeeded in finding a solution so far.
Which comparable aircraft did you find with a pitch MOI of ~7000 ?
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The MOIs have been a source of confusion with this game - Roskam's paper 'Airplane Flight Dynamics and Automatic Flight Controls Part I' gives many calculated coefficients including MOIs for various 'typical aircraft' in the appendix. The nearest to the Pipers is a C172:
(From top: Pitch, Roll, Yaw, coupled).
The figures in the PA28 release were calculated using a tool which is based on his work, and in all previous sims worked well. My current MOI setting for the PA28s, based on the fact that MSFS does not follow aerodynamic conventions, has basically added 2000 to each MOI and as far as I can see, the twitch is still present and the 'feel' has been detrimentally affected. The fact that the Pitts has a pitch MOI of 527, the CAP10c 905, the C172 is at 2000 (note the last is more than double Roskam's calculated figure), suggests that the problem does not lie there. IF altering it to a non-realistic value were to solve the problem, then I would say it is simply masking a problem elsewhere. As I have noted before, using the forces debug tool I am seeing a rapid and continuous reversal of force on the horizontal tail from upwards to downwards at a frequency which appears to tie in with the twitch. It's a shame that so much of the core flight model is still undocumented and in many respects aerodynamically illogical because it leaves us reliant on others (Asobo) to solve this sort of issue. They built it, they strayed from aerodynamic principles (which FSX / P3D were firmly rooted in), they have given us a massive headache trying to deal with this sort of issue which should be a quick fix but instead leaves all the people that have looked at this scratching their heads and playing guessing games. Multiple people have looked at this on our side, nobody has succeeded in finding a solution so far.
Which comparable aircraft did you find with a pitch MOI of ~7000 ?
Thanks for the explanation, very interesting indeed. It sounds like a right PITA dealing with the higher powers - I hope you can get it sorted eventually.
I'll have to go back and find which aircraft I saw with that high MOI. I was just flicking through all the SE pistons that I have.
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Just send a ticket to support myself. Same issue as the Turbo Arrow with the pitch jerks. Had hoped it would be very minor, like the normal Arrow since it is even slower. Turns out is it as bad or even worse then the Turbo Arrow. Really gutted.
Made a little clip. Sorry for the low FPS, Gforce experience lowers it i think.https://www.youtube.com/watch?v=llGYChvz_1I&t=21s