F-16 Nose Wheel Steering Issues

Here is the issue:on the ground at just about any speed above 40-50 knots, the F-16 drifts wildly- much more so than an other aircraft. This is true both during takeoff and landing.

Here is what I have done so far to troubleshoot:

-I have been reading the forums about optimal tweaking values for rudder Axis values (curvature, deadzone, etc.) but none of this seems to make a difference for me.

-I have tested using an empty payload to eliminate balancing issues

-Looking at the external model, the wheels seem to be stationary- not drifting

- I view the controller mapping on screen and confirm that there is no unintentional input coming from the Warthog controller.

Despite all of this, the Viper veers every time. At this point it feels more like a bug than an issue with my setup so I am posting it here.

Any thoughts or other stories confirming this issue would be appreciated.

Thanks

I've noticed something similar. I don't want to say its a bug, probably more likely my set up, but Viper tuning will be an ongoing work in progress.

Having made similar checks to ensure controllers are operating correctly.......No wind. No turbulence.

If I apply full foot brakes and hold, add 90% power, nws on, the nose drifts right whilst stationary.

Release brakes.....dare not touch pedals until I can switch of nws.

Generally as the speed builds I'm dancing on the rudders like its a Spitfire mk9 to fight the drift. Stick contols centred. No other inputs.

Hey....that may be realistic.

I’ve experienced the same thing. It feels like there’s not enough mass on the landing gear. It gets light and squirrelly almost immediately.

Quote "Hey....that may be realistic."

Would make a formation takeoff extremely dangerous ?

Would make a formation takeoff extremely dangerous ?

I'm so glad you agree....

The Viper demo team at this years RIAT had a jet thet was literally falling apart. Didn't see that wobbling????

I’ve experienced the same thing. It feels like there’s not enough mass on the landing gear. It gets light and squirrelly almost immediately.

Same (sad) experience here. Just hoping this will be fixed ASAP, it's more than a dangerous issue IMHO.

With best regards.

IRL, should MMC / CADC automatically senses and trims for the big weight imbalance of in between "AL "and " FR " fuel tanks ?

I have this issue also using my T16000M. As soon as I disengage NWS the plane is easily controllable but my typical mode of accelerating up to ~50kts with NWS on then disengaging is almost impossible to control with the F16.

I have a very inaccurate twist grip and I find that I also have difficulty maintaining directional control on takeoff in the Viper. I have to start the takeoff with NWS disengaged.

I'm able to keep NWS engaged until about 80KIAS in the Warthog. The Viper feels fine at slow taxiing speeds.

Perhaps NWS gain (smaller deflection with increasing airspeed) is not implemented yet?

i have experienced the same thing. I think its due to crosswind on the runway as she always wants to turn into the wind on the run.

Wondering if that is something the FLCS should be calculating/compensating as it FBW rather than stick'n'rudder. I'm not an SME so can only guess

I have the same issue. I'm an ex fighter pilot and this can't be as it should be. The WW F16 fleet would be decimated at each takeoff. The grip on the nosewheel seems by far too high, like a racecar which is too much 'on the nose". Also, I would expect the real implementation to have NWS gain controlled by ground speed.

This wouldn't have passed Air Force acceptance test even if LM would have left it this bad. Something to check and fix for the modelers.

I have the same issue. I'm an ex fighter pilot and this can't be as it should be. The WW F16 fleet would be decimated at each takeoff. The grip on the nosewheel seems by far too high, like a racecar which is too much 'on the nose". Also, I would expect the real implementation to have NWS gain controlled by ground speed.

 

This wouldn't have passed Air Force acceptance test even if LM would have left it this bad. Something to check and fix for the modelers.

At last somebody with real knowledge not with uneducated guess.Thank you!

NWS and ground handling much better in 12/24/2019 relase

I have the same issue. I'm an ex fighter pilot and this can't be as it should be. The WW F16 fleet would be decimated at each takeoff. The grip on the nosewheel seems by far too high, like a racecar which is too much 'on the nose". Also, I would expect the real implementation to have NWS gain controlled by ground speed.

 

This wouldn't have passed Air Force acceptance test even if LM would have left it this bad. Something to check and fix for the modelers.

I've flown the 24 Dec 2019 update, much better. NWS is now less aggressive and the aircraft is wandering less at takeoff or landing. Thanks ED, starting to look like a real aircraft on the ground.

NWS sensitivity varies with pedal set

The ground handling of the F16 is still not OK. It seems to vary with pedal set though.

I started flying the F16 on a TM16000/Throttle/Pedals set. Here the 12/24 release is still a handful. It varies with base, the Vaziani Cold and dark takeoff is tricky even with a Y 45 and Curve at 30! It leaves a too sensitive NWS and too low authority rudder when decoupling the NWS (just did a run to check with reduced Y, otherwise I run Curve 30 only). Then on other bases with std setting except for Curve 30, it's more OK.

This is on my office Envy 34 with i7-8700T and GTX8500. It's not a computer problem, the CPU and graphics are just fine with single-player and graphics at high (the screen is fantastic for DCS BTW).

Then I've built a separate sim rig as DCS is really close to the real thing and it gives me real satisfaction flying fighters again (great job ED). Here I have i7-8700, 32GB, RTX2080, WH HOTAS and CH Pro pedals. And now the aircraft behaves differently! it's less of a handful on the ground despite using normal Y (100) and Curve 30.

Both pedal sets are calibrated and the CH one has cruder 8-bit decoding versus a 10 bit for the TFRP pedals. But they are easier to fly with. Strange.

Other nits: The base engine is too weak at altitude and the auto-trim is too weak (I haven't flown the F16 though but other FBW aircraft with auto-trim), the pitch channel is too insensitive with a displacement stick around zero (will try a negative curve but as 99% has displacements sticks you ought to handle it in the applicaton) but you should know all this.

I've been part of developing fighters and I think your NWS problem is to high grip level on the nose wheel. It's significantly smaller than the main wheels and has less weight on it, hence significantly less grip and more tire deformation and slip. The main LG on the F16 is a swing axle design (like the Beetle) and has a narrow track. So it's not great (camber and track change when suspending) but I can't believe it's this bad in its grip level vs the nose wheel. We have 4k F16 in the field and very few ground roll accidents. The real F16 should be OK to handle for the least proficient pilots.

It could also be the real F16 has NWS gain scheduling or/and a weak link NWS and you implement with no schedule and/or a stiff link NWS.

Please look at this further,

some takeoffs need to be aborted !

Very Frustrating

Thanks

Since release, the DCS F-16 nosewheel steering/rudder input has been significantly different compared to other aircraft. This may or may not be true to real aircraft behavior. I find the F-16 requires constant rudder input on takeoff and landing rolls in all weapon loadouts and/or clean. I find that it can be managed though and that I can maintain centerline if I continually "dance" on the pedals. It's really an art form that requires a bit of finesse.

Fighters are steady as rocks on RWY

Since release, the DCS F-16 nosewheel steering/rudder input has been significantly different compared to other aircraft. This may or may not be true to real aircraft behavior. I find the F-16 requires constant rudder input on takeoff and landing rolls in all weapon loadouts and/or clean. I find that it can be managed though and that I can maintain centerline if I continually "dance" on the pedals. It's really an art form that requires a bit of finesse.

The Fighters I've flown are steady as rocks on the RWY when taking off or landing and I can't believe the F16 is different. They are heavy lumps (10 metric tonnes or more) and don't weer of a straight-ahead trajectory easily, even in crosswind situations or RWYs which are a bit canted/uneven. It shall be adapted.

Sadly, unbalanced ground handling, especially during take off and landing is a DCS tradition.

I can make air refueling, carrier landing but during landing, i find myself dancing on the runway lfrom left to right..

Hotas Warthog and TM pedals here, I couldent keep it down the center line on takeoff or landing for a million dollars.

it handles like an RC plane.

I have Thrustmaster TFRP pedals and need a +50 curve.

I have had the problem in both OB and Stable. My two cents, it only happen when I am close to the taxi, and rwy center lines. Away from them, and all a/c track straight.

The Viper has a very short wheelbase, i.e. the distance from the nosewheel to the main gear, so this behavious doesn't seem suprising to me at all. Intuition, and a fairly decent knowledge of physics tells me that this is fairly accurate, UNLESS there is some sort of NWS damping sytem in the real thing.

IMO the issue isn't how it doesn't track straight, but rather how extremely sensitive the NWS is. Even when taxiing at 15 knots it feels like your going 200 kph down the autobahn on a unicycle. There is no way that's how sensitive it is in real life. Who would design something like that? In it's current state the most difficult part of any takeoff in the F-16 is when you're between 0 and 50 knots when the nosewheel is too sensitive to be of any use at all and the tail fin doesn't have enough airflow to be effective.

IMO the issue isn't how it doesn't track straight, but rather how extremely sensitive the NWS is. Even when taxiing at 15 knots it feels like your going 200 kph down the autobahn on a unicycle. There is no way that's how sensitive it is in real life. Who would design something like that? In it's current state the most difficult part of any takeoff in the F-16 is when you're between 0 and 50 knots when the nosewheel is too sensitive to be of any use at all and the tail fin doesn't have enough airflow to be effective.

A big issue is with the tyres being too grippy laterally, as I noted here: https://forums.eagle.ru/showthread.php?t=262823

With my mod the aircraft is MUCH easier to steer on takeoff because the nosewheel is much less grippy so steering seems much more progressive.

Unfortunately my mod doesn't work any more in 2.5.6, but I'm going to take a look at that later tonight.

15 knots for taxi is considered normal for straight line, but too fast for sharp turns. You should be at 10 knots or less for 90° or more.

The takeoff directional control issues may be linked to landing directional control issues seen here.

https://forums.eagle.ru/showthread.php?t=262823