Landing gear problems

[Delay]

I'm currently experiencing problems when landing any airplane. As the nose gear touches down, no matter how smooth I do it, it jumps up and pulls the nose to 45° or more. And in the case of my newest airplane, it destroys both engines as they hit the runway.

I have tried changing the" damper" and "spring" settings, but they don't seem to get rid of the jumping, nor ease it. I have no clue what causes it, since the main gear never ran into this issue.

How do I fix it? It makes ingame aviation unnecessarely difficult.

[Gaarst]

Wheels physics are still a bit wonky, even after the numerous patches of 1.1 and 1.2. While it has gotten better overall, some weird things still happen, especially with the non-steerable fixed gear (you're "lowriding" as soon as you touch the runway).

To help with this, you can try messing with the spring and damper settings (as you already did) which my help, or you can try to land more gently which again may or not help.

There are probably some fixed made by the community, but I can't remember any off the top of my head (I know @GoSlash27 was pretty involved in this in 1.1, so he might be able to help you better than I did).

[bewing]

What version are you running? The wheel jump you are describing sounds exactly like a problem with clipped wheels in version 1.1.

If you are running an unmodded version of the game, then posting a craft file would be helpful.

 

[Delay]

5 minutes ago, bewing said:

What version are you running?

1.2.2. And it is completely unmodded.

 

6 minutes ago, bewing said:

then posting a craft file would be helpful.

I don't know how to attach files here, but I can do it if it is necessary. It happened with every craft I built.

[GoSlash27]

Yeah,

 Landing gear (especially the fixed gear) are still a little wonky, but much better than they were in the initial release. I really can't comment without seeing the aircraft.

Best,
-Slashy

[bewing]

3 hours ago, Delay said:

I don't know how to attach files here

There are several methods. You can set up a KerbalX or Dropbox account. Or you can understand that craft files are just text files -- find and open the craft file for that ship, copy it into your clipboard, go to pastebin.com and paste into the window there. Then post the "raw" download link that they give you.

 

[AeroGav]

As a general tip, the first wheels to touch the ground (that take the force of impact) should be as close to CG as possible.    That normally means the main gear. This minimises the nose up/down rotation caused by the impact.

Often, I found my nose gear legs that protruding down further than the mains, due to me attaching the mains to the wings , in the quest for  a wider track, whilst the nose gear is attached to the bottom of the fuselage.

I thought the nose up resting stance would be a benefit, but actually it causes "wheelbarrowing" when speed builds up,  and unless you land at high aoa, going very slowly near the stall,  the nose gear is first to hit the ground.   The impact bounces the nose back into the air, suddenly increasing aoa and converting the excess airspeed to lift.   If the jets are slow to spool back up, this can lead to you stalling back onto the ground from the bounced landing.

IRL this has caused some nasty accidents.

 

[ajburges]

Without demo pics/files I can only offer a few of my observations.

Pitch up effect often comes from contacting first with gear forward of CoM and rebounding. The only way to address this is to reduce the strength of the rebound or move it:

Contact with wheels closer (and behind) the CoM first. The rebound from their contact behind CoM will reduce AoA instead of increasing it. Also, the closer to CoM the rebound is, the less torque it applies so you bounce instead of pulling up.

You can also reduce forward gear spring coefficient to reduce the strength of their rebound. I think you still want to keep them critically dampened. You can also play with the main gear as well.

[Delay]

I fixed it.

By increasing "spring" and "damper" to 2. Works really well on both the runway and on terrain (made a visit to Baikerbanur/KSC 2).

I land at about 60-75 m/s, which is just above take-off speeds. So the main gear touches down first.