[FIXED] Strange flgiht behavior

I have this problem also, have to use autopilot to keep the plane horizontal otherwise it will keep rolling left (very subtle but noticeable).

I have attached a track of the F/A-18 showing no left yaw on takeoff. Conditions are the exact same as my F-16 tracks...aircraft are clean with no pylons, no wind. For each takeoff, my feet were on the floor and no rudder input was made.

Why does the F-16 yaw left on takeoff and the F/A-18C does not? Is this accurate behavior?

F-18 takeoff.trk

Why does the F-16 yaw left on takeoff and the F/A-18C does not? Is this accurate behavior?

No, this wouldn't be accurate and it doesn't yaw at all on my install..

Regarding the plane wanting to turn a tiny bit to the left I can confirm that is also my impression.

AND

After the latest update if you have two tanks on the wings and fly over 400knots then the Heads up display start to bump up and down all the time.

That must be a mistake ( the F18 and other planes do not behave like that )

No, this wouldn't be accurate and it doesn't yaw at all on my install..

Well, I have no idea what is happening. The fact that it only does it with the F-16 and no other aircraft rules out a problem with my rudder or calibration. I have also checked to make sure there are no conflicting controls and that nothing else is assigned to the rudder axis. I have used the Thrustmaster calibration tool and controls are centered and functioning properly.

I have even unplugged my rudders and results are the same...F-16 yaws left on takeoff and other aircraft stay straight.

Okay, here is something to add...

All of my takeoffs have been at Nellis so far. Just for the heck of it, I decided to test this behavior at Al Minhad on the Persian Gulf Map. During this takeoff, I actually experienced a very slight right yaw on takeoff but it stayed straight for the most part.

What in the world would explain this?

Okay, here is something to add...

 

All of my takeoffs have been at Nellis so far. Just for the heck of it, I decided to test this behavior at Al Minhad on the Persian Gulf Map. During this takeoff, I actually experienced a very slight right yaw on takeoff but it stayed straight for the most part.

 

What in the world would explain this?

What do you get if you take off in the opposite direction on the same runway?

What in the world would explain this?

Crosswind.

What do you get if you take off in the opposite direction on the same runway?

The same behavior, left yaw.

I did a takeoff at Batumi and had left yaw as well. Only the takeoff at Al Minhad yawed to the right. All takeoffs on NTTR and Caucasus yaw to the left. Strange!!!

I repeated all takeoffs in the Hornet and it stayed right on centerline during the entire takeoff roll.

Crosswind.

There is no wind present. All wind is set to 0 in the mission editor, default weather.

The same behavior, left yaw.

To clarify I was just talking about the takeoff from Minhad. You reverse takeoff direction and the swing reversed or not?

To clarify I was just talking about the takeoff from Minhad. You reverse takeoff direction and the swing reversed or not?

Okay, just tested opposite runway takeoff at Al Minhad...the yaw was back to the left. So, runway 27 was yaw to the right and runway 09 was yaw to the left. Yaw is always to the left at Nellis and Batumi no matter the runway direction.

Flight character high speed wobbling

with empty plane and flightspeed over 500kts then give full rudder in one direction. The result is a big amplitude of wobbling and over compensating from the flightcomputer. nearly the flight controls are out of order.

F-16 Oscillations and Pitch/Yaw Problem

Aircraft will go into a heavy left - right oscillation when using slight rudder sometimes. And sometimes will pitch up and down uncontrollably (which I do not have a video of) but, the aircraft will go full pitch down and full pitch up, blacking you out, and it does this for about 10-15 seconds at least.

Here is the left-right oscillation. https://www.youtube.com/watch?v=5n1YRG4sXbs

Could it be gyroscopic precession from the big hunk of metal spinning at 25000 rpm inside the engine?

Could it be gyroscopic precession from the big hunk of metal spinning at 25000 rpm inside the engine?

That is an interesting point - you know I have been and aircraft engineer for 25 years and never really considered that as a problem. I guess it was something we didn't really think of as having a very big impact.

Engines do have rub lining on the cases and in particular for the fans of high-bypass engines for any minor misalignment caused by these forces - but again this is very minor.

Pitching the engine would give a commensurate yaw L or R depending on engine rotation and weight, but I imagine the FBW system should handle that fairly easily, given that the mass of the actual rotating core in an F-16 engine is only a small fraction of the total weight of the aircraft (200kg vs 20 ton), the actual impact on directional control of the aircraft would be minimal at best.

OT Edit:

Also on split spool engines it is possible to have each spool rotating in the opposite direction to counter these forces (just reverse the blade arrangement on the disc) - RITE, or dual compressor rotor - https://patents.google.com/patent/US8356469B1/en

Found out today:

@ NTTR: Slightly turning left constantly.

@ Persian Gulf with same loadout: No issues.

Same weather - No winds

I have noticed that this has been consistent with whatever direction of the turn I go into.

If I am turning left, it continues the turn even after banking and trimming into S/L flight. If I turn right, it does the same. It is also demonstrating negative static stability (which shouldn't matter with a FBW flight control system). Meaning, the turn exacerbates and moves away from equilibrium.

I cross posted in control inputs, but I have a Virpil stick, properly calibrated, no dead zones, and hands off on most of this save for the trim.

I have noticed that this has been consistent with whatever direction of the turn I go into.

 

If I am turning left, it continues the turn even after banking and trimming into S/L flight. If I turn right, it does the same. It is also demonstrating negative static stability (which shouldn't matter with a FBW flight control system). Meaning, the turn exacerbates and moves away from equilibrium.

 

I cross posted in control inputs, but I have a Virpil stick, properly calibrated, no dead zones, and hands off on most of this save for the trim.

Yeah, I don't think this is a control issue or an issue on the user's end. Too many people are experiencing this and for me at least, I only see the uncommanded yaw on takeoff/roll while airborne in the F-16 and not with any other aircraft.

Yeah, I don't think this is a control issue or an issue on the user's end. Too many people are experiencing this and for me at least, I only see the uncommanded yaw on takeoff/roll while airborne in the F-16 and not with any other aircraft.

I agree.. If 75+% of the users show this issue, it's an issue..

I tried this again and it is clearly linked to the fuel quantity in the wing external fuel tanks.

After flying for a while and monitoring the ext fuel tank quantity, the left roll disappear as soon as the tanks are empty.

For some reason it is not doing it when air starting

Yea I actually noticed yesterday flying with external tanks and switched QTY Indicator to EXT that there was an excessive quantity split (red needle indicator visible) till the tanks were empty.

After today's latest patch, I am still experiencing left yaw on takeoff and left roll while airborne. Clean jet, no pylons, no wind.

I have included several tracks of the F16 showing the behavior on each map as well as tracks with the Hornet showing no yaw on takeoff.

For the track that shows the left roll while airborne, I made no inputs other than throttle and then turned on the autopilot. Once stabilized, I turned off the autopilot with no further control inputs. After a bit, you can see a slight left roll begin and a degree change in heading.

F-16 left yaw takeoff Nellis.trk

F-18 no yaw takeoff Nellis.trk

F-16 left yaw takeoff Batumi.trk

F-18 no yaw takeoff Batumi.trk

F-16 left yaw takeoff Al Dhafra.trk

F-18 no left yaw takeoff Al Dhafra.trk

F-16 left roll airborne.trk

When engine spools up rapidly, the interia from the engine should induce a roll left and Pretty aggressive one too.

Maybe this is modeled, but not tied into fan acceleration/deceleration but rather to RPM. (Constant RPM is neutral)

When engine spools up rapidly, the interia from the engine should induce a roll left and Pretty aggressive one too.

 

Maybe this is modeled, but not tied into fan acceleration/deceleration but rather to RPM. (Constant RPM is neutral)

It happens in straight and level flight without moving the throttle as well, so it cant be that

It happens in straight and level flight without moving the throttle as well, so it cant be that

Unless that is the bug :)