Nealius Posted December 15, 2021 Share Posted December 15, 2021 Attaching a track. Happens to both A and B models. Hot ramp start. Rudder axis is not assigned to any controllers. There is zero rudder input being sent to DCS. Some movements are smaller than others. There's at least one fairly large movement visible. Not sure what's going on here. Rudderspasm.trk 1 Link to comment Share on other sites More sharing options...
Gunslinger22 Posted December 15, 2021 Share Posted December 15, 2021 Interesting, just finished a flight when on the ground I noticed my rudders moving, check all axis and much like your findings there were no inputs other than some DCS magic going on. 1 "I'm just a dude, playing a dude, disguised as another dude." Link to comment Share on other sites More sharing options...
Nealius Posted December 15, 2021 Author Share Posted December 15, 2021 It seems to be caused by wind and/or turbulence. Winds 6kts, turbulence 40 (average day for flying gliders): Rudder moves. From 0:56 to 1:20 you can see almost full rudder deflection during some spasms. Winds 0kts, turbulence 0: Rudders stationary for full 2 minutes. Rudder0Wind0Turbulence.trk RudderwithWindandTurbulence.trk Link to comment Share on other sites More sharing options...
fat creason Posted December 15, 2021 Share Posted December 15, 2021 Probably the Yaw SAS... Systems Engineer & FM Modeler Heatblur Simulations Link to comment Share on other sites More sharing options...
Spartan111sqn Posted December 15, 2021 Share Posted December 15, 2021 2 hours ago, fat creason said: Probably the Yaw SAS... Yaw SAS coordinate rudder in DCS?, I thought that it was when DFCS was implemented in RL, but not in DCS, right? Link to comment Share on other sites More sharing options...
fat creason Posted December 15, 2021 Share Posted December 15, 2021 (edited) https://www.heatblur.se/F-14Manual/cockpit.html#afcs-control-panel In case you're not aware, there's an AFCS panel on the left side of the cockpit. Note the labels on the AFCS panel... Edited December 15, 2021 by fat creason Systems Engineer & FM Modeler Heatblur Simulations Link to comment Share on other sites More sharing options...
IronMike Posted December 15, 2021 Share Posted December 15, 2021 Wind and high turbulence in DCS pushes rudders. I always thought this effect to be exaggerated tbh. Heatblur Simulations Please feel free to contact me anytime, either via PM here, on the forums, or via email through the contact form on our homepage. http://www.heatblur.com/ https://www.facebook.com/heatblur/ Link to comment Share on other sites More sharing options...
Nealius Posted December 15, 2021 Author Share Posted December 15, 2021 5 hours ago, IronMike said: Wind and high turbulence in DCS pushes rudders. I always thought this effect to be exaggerated tbh. Just investigated with all high-fidelity non-FBW jets, plus the Mosquito for good measure (massive rudder, no hydraulics, no prop wash). 6kt crosswind from rear quarter, turbulence 40. A-10C II - No movement AV-8B - No movement AJS 37 - No movement F-86 - No movement L-39 - No rudder movement, but the aircraft itself yaws around on the ground Mig-15 - No movement Mig-19 - No movement Mig-21 - No movement Mosquito - No movement The F-14A/B appears to be the only one with this involuntary rudder movement. 1 Link to comment Share on other sites More sharing options...
IronMike Posted December 16, 2021 Share Posted December 16, 2021 1 hour ago, Nealius said: Just investigated with all high-fidelity non-FBW jets, plus the Mosquito for good measure (massive rudder, no hydraulics, no prop wash). 6kt crosswind from rear quarter, turbulence 40. A-10C II - No movement AV-8B - No movement AJS 37 - No movement F-86 - No movement L-39 - No rudder movement, but the aircraft itself yaws around on the ground Mig-15 - No movement Mig-19 - No movement Mig-21 - No movement Mosquito - No movement The F-14A/B appears to be the only one with this involuntary rudder movement. Thank you! We will take a look as to why that is. 2 Heatblur Simulations Please feel free to contact me anytime, either via PM here, on the forums, or via email through the contact form on our homepage. http://www.heatblur.com/ https://www.facebook.com/heatblur/ Link to comment Share on other sites More sharing options...
Nealius Posted December 16, 2021 Author Share Posted December 16, 2021 I'll run another test with a 180-deg crosswind at ludicrous knots and thunderstorm-level turbulence to see if I can force the other modules to react. Starting to feel like a Mythbuster with less pyrotechnics. Link to comment Share on other sites More sharing options...
draconus Posted December 16, 2021 Share Posted December 16, 2021 https://www.quora.com/Why-is-the-rudder-of-an-aircraft-towards-the-left-when-you-view-it-from-the-nose-when-parked-at-the-airport?share=1 https://en.wikipedia.org/wiki/Gust_lock So wind gusts on rudders are a real thing and concern but I have no information how much the Tomcat would be affected. I guess HB will ask their SME's on the matter. That other modules do not behave the same it may as well mean just that they are not modeled to that extent. Win10 i7-10700KF 32GB RTX3060 Rift S T16000M TWCS TFRP FC3 F-14A/B F-15E CA SC NTTR PG Syria Link to comment Share on other sites More sharing options...
r4y30n Posted December 16, 2021 Share Posted December 16, 2021 Lack of hydraulic pressure after shut down seems plausible. With the engines running I don’t think there would be any movement, given the irreversible controls. Link to comment Share on other sites More sharing options...
Nealius Posted December 16, 2021 Author Share Posted December 16, 2021 With engines off and no hydraulic pressure, yeah I can see wind moving the rudders. On a ramp hot start with engines running and good hydraulic pressure I would think nothing less than tornado winds would move the rudders. Link to comment Share on other sites More sharing options...
IronMike Posted December 16, 2021 Share Posted December 16, 2021 (edited) So, @Cobra847 corrected me and pointed out that I was likely misremembering, since the animation of control surfaces is 100% driven by us, and not by the core game. Thus I likely remembered seeing it on other modules, while I likely only saw it on ours. We will investigate how plausible it would be (some good points have been mentioned above) and why it is as is where it shouldn't be like that. Thank you all again for bringing it to our attention. Edited December 16, 2021 by IronMike 2 Heatblur Simulations Please feel free to contact me anytime, either via PM here, on the forums, or via email through the contact form on our homepage. http://www.heatblur.com/ https://www.facebook.com/heatblur/ Link to comment Share on other sites More sharing options...
fat creason Posted December 16, 2021 Share Posted December 16, 2021 (edited) Yeah I was about to say...wind is not a factor in the rudder code anywhere. Any "involuntary" movement of the rudder is almost certainly the Yaw SAS. Edited December 16, 2021 by fat creason 1 Systems Engineer & FM Modeler Heatblur Simulations Link to comment Share on other sites More sharing options...
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