Swerve all over the place on landing and tackoff - Why?

[Crunchy]

Why does this aircraft not stay straight on the runway? When I tackoff I swerve to one side and it's very hard to correct this with Saitek Combat rudder pedals. The same goes for landing, as soon as the aircraft start slowing down it swerves to one side. When you try to correct this by pushing the rudder down in the opposite direction you end up snaking all over the runway.

 

Has anyone got a good setup for the Saitek Combat rudder pedals they could give me because I'm hoping it's just that causing the problem. Seems even worse with the latest patch for DCS World.

 

Edit: I just want to add that it seems to be a lot worse in Multiplayer for some strange reason.

Edited February 10, 2016 by Crunchy

[PiedDroit]

I assume there is no crosswind?

Do you accidentally press the toe brakes? Is one toe brake slightly stuck?

I know it's obvious but it happened to me a lot of time until I corrected the way I put my feet on it, when flying tbe A-10.

edit: There was a gear symmetry problem in past versions but it should be fixed by now.

Edited February 10, 2016 by PiedDroit

[Crunchy]

I assume there is no crosswind?

Do you accidentally press the toe brakes? Is one toe brake slightly stuck?

I know it's obvious but it happened to me a lot of time until I corrected the way I put my feet on it, when flying tbe A-10.

 

Yeah, there might be crosswind in Multiplayer, I never thought about that to be honest. But if it is down to crosswind it's still virtually impossible to keep the Mirage straight or even on the runway at times. I have no problem in the A10C, it's only the Mirage2000. I checked my brakes and the toe brakes are not sticking.

 

I just read a thread where someone mentioned using just one key for brakes, but that was last December. Does this still apply now though, is it better using one key for brakes instead of two toe brakes?

[droopy114]

Yeah, there might be crosswind in Multiplayer, I never thought about that to be honest. But if it is down to crosswind it's still virtually impossible to keep the Mirage straight or even on the runway at times. I have no problem in the A10C, it's only the Mirage2000. I checked my brakes and the toe brakes are not sticking.

 

I just read a thread where someone mentioned using just one key for brakes, but that was last December. Does this still apply now though, is it better using one key for brakes instead of two toe brakes?

I agree, impossible for me to, always going to the right side of the runway when taking off/landing.

[PiedDroit]

Yes you can use one key to brake, it makes braking easier indeed.

Also you are maybe braking too soon, I apply brakes under 80 knots usually, after letting the aircraft slow down by itself.

But all of this applies to landing, if you're swerving on take off also it might be just crosswind.

 

I agree, impossible for me to, always going to the right side of the runway when taking off/landing.

Maybe the symmetry problem wasn't fixed after all. I don't notice it anymore but it might be still here?

Edited February 10, 2016 by PiedDroit

[ScapaFlow]

Edit: sounds like I'm making a complaint, didn't mean it that way, was just an observation. Happy with the module!

 

(1.5.2) for me and 3 other people I know who own M2000, it really, really wants to swerve when taking off, no external load/full load, in multiple missions, some with 0 wind.

Experimenting with the NWS (using it up to 30 kts/using it more than that/not using it at all) makes some difference, but not a huge difference.

 

In comparison, a MiG-21 or -15 in comparison is much more stable on take-off.

Considering the FBW M2000 is much more stable in-flight than the MiGs, it feels strange that it should be so unstable on take-off.

Edited February 10, 2016 by ScapaFlow

[Pikey]

I find its not the instability, but the delay that causes yaw oscilations so you constantly over correct. So a little rudder, then later the aircraft yaws. But you already put in rudder because you were bored waiting. Cross wind is currently tricky, not as tricky as a prop though.

[claw]

In the Mirage I noticed it helps a lot when you pull the stick back during the entire take-off. Also check if the nose wheel is locked or unlocked.

[BaconSarnie]

Someone explained to me the other day, nose wheel steering automatically turns of at 40KTS, but the rudder only becomes effective at 90KTS or so.

So you have a whole 50KTS region where no steering inputs are valid.

Dunno if its right, but seems plausible to me.

Edited February 10, 2016 by BaconSarnie

[droopy114]

In the Mirage I noticed it helps a lot when you pull the stick back during the entire take-off. Also check if the nose wheel is locked or unlocked.

 

This. The only solution I've found. Don't know if it's correct behavior or flight model need more tweak, maybe devs may comment on this?

[dotChuckles]

Also, the ground handling is still work in progress and if i'm not mistaken, is being addressed in a future update.

[jaguara5]

Last november i visited Tanagra AB, homebase of HAF's Mirages.

Had an extensive conservation with a - C pilot about crosswind landings. He told me that crab is the used technique.

After touchdown, the plane aligns itself with the centerline of the runway, and that is due to the big span between the 2 main weels (same for the f-4), and little rudder input is required. I remember, he made a characteristic movement with his shoulders to demonstrate this ''Auto correction'' movement.

This feature is totally missing in the simulation now.

If i remember correctly, there was in BMS forums a related topic, where these things were explained technically.

Edited February 10, 2016 by jaguara5

[droopy114]

Made some corrections both to the FBW yaw controller, as well as to rudder/vertical tail aerodynamics in the past couple of days that should help this out.

 

Did a test last night (with no wind) full AB and stayed straight down runway with no rudder input way past rotate speed.

 

Did a similar test with a 18 knot crosswind and seemed to have a much easier time maintaining centerline and I definitely didn't max out on my rudder authority like I was before.

 

So we're getting there :)

 

One thing I am looking at this evening is adjusting control delay on the rudder, especially in gear down mode when rudder input is more important. Something in the filtering I feel is making it more sluggish than it should be.

Thank you for your comment!

[enigma6584]

Someone explained to me the other day, nose wheel steering automatically turns of at 40KTS, but the rudder only becomes effective at 90KTS or so.

So you have a whole 50KTS region where no steering inputs are valid.

Dunno if its right, but seems plausible to me.

 

You know I have yet to see the nose wheel steering automatically turning off after so many knots down the runway. I remember reading this as well but it is not working for me. Anyone else notice this or is it just me?

[Crunchy]

You know I have yet to see the nose wheel steering automatically turning off after so many knots down the runway. I remember reading this as well but it is not working for me. Anyone else notice this or is it just me?

 

I also read it, but nose wheel steering seems to stay on for me. So is NWS supposed to disengage after 40Kts or not?

[joey45]

Post a track.

[PiedDroit]

I also read it, but nose wheel steering seems to stay on for me. So is NWS supposed to disengage after 40Kts or not?

NWS will disengage but the blue light stay ON

[Teeter]

NWS will disengage but the blue light stay ON

 

Correct, right now it's modeled as a gain of sorts. At 0kn, you have full steer authority, but the gain is decreased gradually until you have 0 authority at 60kn. I will add the logic to just turn the NWS off.

[PiedDroit]

Correct, right now it's modeled as a gain of sorts. At 0kn, you have full steer authority, but the gain is decreased gradually until you have 0 authority at 60kn. I will add the logic to just turn the NWS off.

I thought it was the correct logic (the pilot knows it's not operating below X knots).

I'm OK either way as long as we don't fall into a state where the light is OFF but the pilot doesn't know if the system is actually ON or OFF.

 

If the light (DIRAV) turns OFF when the speed is higher that X knots, the system should be also disengaged for good (requiring a new press on the HOTAS button to re-activate it).

[KLR Rico]

Glad I'm not the only one that has had trouble keeping the M2K on track. Any crosswind and I'm all over the place, it makes my taildragger handling look amazing in comparison.

[Teeter]

Guys, I've tweaked the NWS gain a bit and it feels good to me. I'll be curious to hear your thoughts about it. Although I feel we may need some more tweaking.

[gospadin]

I've had a lot more luck landing without a swerve if I push the stick all the way forward before applying wheel brakes.

 

Not sure why this matters, but the plane swerves a lot less this way.

[haffende]

I also have this problem...its a very annoying bug that's been around for a while now in 1.5.2 and 2.0.1. I am using an X55 set up properly calibrated. No matter what I try, take off is just plain ridiculous and unrealistic and is ruining my experience with this fine machine. Landing is also crazy and any braking results in a ridiculous uncontrollable skid. No other DCS planes have this problem. I hope this will be sorted soon as its begining to grind now....please focus on the basics before sorting out the more complex stuff. I am finding the M2M M2000C in FSX flies better at the moment !!

[emg]

Just pull the stick back when you start rolling, did some formation take-offs and landings in MP. No need to brake early when landing, just land at the beginning of the runway. Still it's nice to see the dev feedback.

Edited February 13, 2016 by emg

[Teeter]

We've been doing a LOT of tweaks to ground handling, rudder authority, gear stiffness and strength, etc internally and are very happy with its current state. We'll be curious to hear some more once you all get to try it out.