[Bug] Possible FFB bug

[Phantom12]

So I discovered some odd behaviour that I was able to replicate a few times and I think its possible its a bug of some sort. After an airstart the FFB forces are very light, and then at some point something causes a change and all of a sudden all of the forces noticeably increase, as if something turned up the gains midflight. Best I could track down it seems to happen when the airplane exceeds 24-26 units AoA the first time. After that the forces are turned up and remain consistent. Its most noticeable in Pitch but it affects roll as well. I dont believe its a bellows issue as Pitot heat is on by default and I don't think I flew high enough or long enough for icing to develop. There werent any failures shown in the post flight log either and I dont think i Overstressed the aircraft.

Not sure if its a DCS FFB bug or an F-4 bug (and hopefully not a hardware issue on my end) but Ive included 4 tracks below. I restarted DCS a few times and replugged my stick etc and was able to replicate it fairly consistently. In the later tracks I started with a sustained 500kt turn, to check the forces required, then did some sort of roll or high AoA maneuver. Once AoA increased past the value I mentioned above I could feel the stick instantly get heavier. Afterwards I flew another sustained 500kt turn (without retrimming) to check the forces again. In most of the tracks below the point where forces increased happens right around the time I fly the rolls and level off.

I fly the MT version of DCS and use a sidewinder MS FFB2 stick. 

 

 

F-4 FFB late activation.trk F-4 FFB late activation2.trk F-4 FFB late activation3.trk F-4 FFB late activation4.trk

Edited May 27, 2024 by HB_Painter
Classification of Bugs and User reports

[some1]

Yes, I noticed the same issue and was about to make a bug report too

The problem is that FFB spring force is initially set at lower value on mission start (around 50% I think), while it should be at 100% on airstart when the aircraft is flying at high speed. 

It seems that the joystick spring force gets updated only when the internal FFB calculations drop from 100%. Until then you're flying with half the force on the stick while internally F-4 thinks you're already at 100% so it doesn't send new FFB numbers. When you slow down or start agressive manoeuvres the new FFB spring values will be finally received, and that's what you feel as sudden force increase, because your stick goes from 50% to 99%, 98% etc.

It's more noticeable with high pitch gain settings in special options, because then the Phantom FFB stays at 100% spring in most of the speed range.

[Phantom12]

Thanks, glad to know its not just placebo

[HB_Painter]

Hey thanks for the reports! Looks like a bug we will investigate

[Phantom12]

I felt like this had gotten better after the 1st patch but it still seems to be around even after todays patch. Curiously the force "jump" seems to be triggerable by going into Burner at some points as well.

[some1]

Nope, still not fixed, FFB does not initialize correctly in airstart missions.