Spaceplane landing is ridiculously difficult

[MadOverlord]

I haven't played with the spaceplanes before, but after several hours of messing around with them and being unable to land safely, I'm pretty frustrated (and I speak as someone who has a pilot's license in RL).

There seem to be several problems I am running into:

• The landing gear are more explosive than Nitrogen Tri-Iodide. I have touched down on the runway at well under 1m/sec and blown up.
• Even after a successful landing, hitting any of the imperfections in the runway (even after upgrading it) starts oscillations that cause the plane to tumble and explode. It is insanely frustrating to *finally* get the plane on the ground and be slowing down only to hit a tiny bump and go boom.
• Nosewheel steering is not proportional to groundspeed, so any attempt to correct your path on the ground after landing is likely to put you in a tumble.

Suggestions:

1. Remove explosives from the landing gear. That's bad design even by Kerbal standards.
2. Make nosewheel steering proportional to groundspeed.
3. Damp the oscillations when on the ground.
4. Implement ground-effect into the physics model (increased lift and drag, and less response to control inputs) when within 1 wingspan of the ground)

 

[sardia]

For now, put a 3 sets of parachutes around your plane, it should stabilize it during landing.

[OddFunction]

Wheels are garbage right now. In the meantime, try this fix:

/rant

Edited May 20, 2016 by OddFunction

[Enorats]

Landing planes has always been a skill with a learning curve. That said, a lot depends on the design of the plane and way you approach the runway. It also helps a LOT to use basically any UI other than the stock one. Mechjeb or KER both offer great info panels. The key here is that your "surface velocity" is actually a combination of two velocities.. your horizontal speed and vertical speed. The stock UI doesn't depict this. For example, you may have a surface velocity of "30 m/s" which is quite slow for an approach. But if that 30 is 10 forward and 20 down.. you'll blow up when you hit the runway. If it's 25 forward and 5 down.. well, still pretty fast but you'd likely survive. Basically, keep that vertical speed near zero on contact and get your horizontal as low as possible without stalling.

Never try turning when you're touching the ground. You'll die. It's all but certain, and would happen in real life too. That's why trikes are so dangerous.

[Snark]

One important change with landing gear in 1.1:  Size matters.

Before 1.1, landing gear was pretty much indestructible-- specifically, you could load as much weight onto it as you like.  There was no functional difference between the tiniest landing gear and the biggest, other than how tall it was.  Want to land a 100-ton shuttle on three small landing gear?  No problem.

Now, the landing gear have a finite (and limited!) strength, and size matters.  Bigger landing gear can take more shock, i.e. a heavier load.  If you're trying to land too many tons of plane on too little gear, it doesn't matter a lot how fast you're going when you land, they're gonna pop.  Try putting bigger landing gear on the plane.

That's not to say that there aren't plenty of issues with 'em ... but that particular one has a mitigation.

[G'th]

OR, land in the ocean. Distinctively easier to do and at most you might have an engine be destroyed.

[Sereneti]

or, land with parachutes...
on my first spaceplanes i simply had added enough parachutes to land the spaceplane with parachutes only...

....
if you are landing, you dont have only the "average speed" , the speed on some parts of the vessel can be realy higher than that...
-> touch down with the back landing gear -> the nose can fall down with a realy high speed...

 

[Wheffle]

Your landing gear shouldn't be exploding. If it is, you're using much too small gear. I had issues with the wheels actually popping, and moving up a size in landing gear solved it for me. Now I can slam into the ground pretty hard and everything holds fast.

[Majorjim!]

Nah, its the borked wheels. Landing aircraft/space-planes in KSP is a cakewalk. For lifting bodies just keep the speed up by coming in steep and flair at the last second.

[martinborgen]

Ground effect though! I want! Ekranoplanes omnomnom!

[FancyMouse]

My experience is (based on my several previously perfect working 1.0.5 crafts upgrading to 1.1.2):

1. Nose gear set friction to zero. I observe proper negative feedback when there is a yaw perturbation, and that completely solves veering during taking off/landing.

2. Increase damp to withstand a higher vertical velocity upon touchdown.

3. I feel I need to learn to use flaps (deploying elevons) better than before. Previously I didn't need to do flaps at all, but now it seems it really helps by reducing approach speed.

Haven't seen my landing gear exploding so far. Maybe luck, maybe I just overuse landing gears all the time. We'll see.

[KerikBalm]

I don't find landing too be too difficult (IRL I fly hanggliders and land on my feet), but keeping the plane stable after touchdown is a definite challenge.

My super large SSTOs actually aren't so hard to land in that respect... they hav a very wide wheelbase (because the payload goes in the center), and they have no steerable gear because there is not larger size steerable gear (I've found turning them on the ground to be really hard now... and it won't seem to let me adjust the brake settings on the left wheel without also changing the right wheel... which I could swear used to be an option)

I use braking chutes on all my designs because that intrinsically stabilizes the plane, and makes wheel torque minimal.

Also, half the time I line up for a landing on the grass, and then just roll onto the runway for recovery

[eddiew]

3 hours ago, Majorjim said:

Nah, its the borked wheels. Landing aircraft/space-planes in KSP is a cakewalk. For lifting bodies just keep the speed up by coming in steep and flair at the last second.

Exactly. KSP stock aero is amazingly forgiving, and it's fine to pull bonehead manoeuvres like a flare at 20m altitude. 

The problem atm is, as everyone else has said, wheels are ruined. If you don't spin doughnuts during takeoff and crash without getting airborne, then you're likely to kersplode on landing  

That said, people do seem to expect 10m/s vertical descent to be ok when landing, which is madness. If you drop a plane straight down from the height of a 4 storey building, you'll be lucky if the wings don't fall off on impact!

Edited May 20, 2016 by eddiew

[Curveball Anders]

8 hours ago, MadOverlord said:

I haven't played with the spaceplanes before, but after several hours of messing around with them and being unable to land safely, I'm pretty frustrated (and I speak as someone who has a pilot's license in RL).

Your RL skills and experience might actually be a problem in this case.

I noted that my many (way to many) years with dedicated Flightsims leaves me totally stumped to flying airplanes in KSP.

One has to keep in mind that it's a game focused on space and that atmospheric flight is a bit tacked on.

[Gaarst]

Are landing gears supposed to be weak ? Last time I landed something a bit roughly on the runway in 1.1 my landing gear was fine.

The runway on the other side...

Spoiler

 

[MadOverlord]

Just a quick note to thank everyone for the suggestions and support.

[cantab]

Yeah, in light of the widely reported wheel issues in KSP 1.1 I'd say now is a bad time to try and make standard aircraft. At best you'll learn weird habits that will hopefully be made no longer necessary. At worst nothing will work and you'll get hacked off.

Instead consider VTOLs, the old dodge of whole-aircraft parachutes, or just forget it and fly rockets instead.

[moogoob]

I've been using parachutes to land the Nastybird and Cargobird shuttles. So much more reliable than the runway, but significantly less impressive.

[qromodynmc]

Today i had my first trouble with landing gears, but after switching to bigger gear problem fixed. Probably every gear can carry only limited weight right now.

[RocketBlam]

I just put chutes on my planes and land vertically, engines off. Not so much because landing is difficult... I find it pretty easy actually now, in 1.1.2. My landing gear aren't explosive like they were in 1.1. I just don't want to try to land precisely at the KSC.

Although I find landing on relatively flat terrain elsewhere to be pretty reliable too. I almost wonder if you're not on 1.1.2. They fixed the gear a lot in that patch.

ETA: The guy above me with the unpronounceable name has a good point too: You need the right size landing gear now. Landing big planes on small wheels doesn't work any more. If in doubt, go with bigger gear.

Edited May 20, 2016 by RocketBlam

[Alshain]

1 hour ago, RocketBlam said:

ETA: The guy above me with the unpronounceable name has a good point too: You need the right size landing gear now. Landing big planes on small wheels doesn't work any more. If in doubt, go with bigger gear.

That's true, that part was intended, but there are other issues with gear as well.  Several people are either putting too much mass over the gear, or are landing at a high vertical speed, but I know I'm not and I still can't get off the ground.  The fact they won't even drive straight down the runway is a big problem.

[RocketBlam]

Just now, Alshain said:

That's true, that part was intended, but there are other issues with gear as well.  Several people are either putting too much mass over the gear, or are landing at a high vertical speed, but I know I'm not and I still can't get off the ground.  The fact they won't even drive straight down the runway is a big problem.

Hmm. I think all landing gear steer by default (I mean, other than the first ones). I always forget to turn off steering for the rear wheels. 

Also, using the "move" and "rotate" tools aligns the part to the global space, rather than the vehicle part space. What this means is that if you rotate it so it looks straight using the rotate tool, it should be perfectly straight.

[Alshain]

3 minutes ago, RocketBlam said:

Hmm. I think all landing gear steer by default (I mean, other than the first ones). I always forget to turn off steering for the rear wheels. 

Also, using the "move" and "rotate" tools aligns the part to the global space, rather than the vehicle part space. What this means is that if you rotate it so it looks straight using the rotate tool, it should be perfectly straight.

I'm aware of all of that, I've been building planes for a VERY long time in this game.  It's nothing to do with building, the wheels are just broken.  Some of these planes weren't even built in 1.1 and worked fine in previous versions.

[RocketBlam]

Hmm, not sure what it could be then. I've only created a few spaceplanes since 1.1.2, but I've landed one on uneven terrain far from KSC, and didn't have any wheel issues. But I've heard of others still having issues, so... I certainly haven't done it all in 1.1.2.

[RocketBlam]

17 hours ago, KerikBalm said:

and it won't seem to let me adjust the brake settings on the left wheel without also changing the right wheel... which I could swear used to be an option)

Just an idea, but if you place the wheels one at a time (instead of mirror geometry) they won't be part of a set, so you should be able to adjust them individually.