"Landing" a plane on a mountain with FAR

[PunkyFickle]

Warning : mild anomaly spoilers

I've always used FAR for the challenge and sake of realism, but never really flown a plane because of the difficulty of such a thing and because I focus my KSP games on career, which have you very rapidly leave Kerbin's atmosphere for farther and oddly shaped horizons. Sure did I attempt a few test flights to get my hands on it knowing I would want to fly spaceplanes at some point, but even with a handful of tutorials for designing and flying planes (and understanding the UI) and a good amount of practice, I never managed to land anything. Problems during take off are easily solved and flying an eventually balanced plane is not too difficult with a joystick, but landing with FAR was a nightmare and all my test flights would end up in a ball of fire. So I ended up giving up and decided to postpone flight mastery to another day.

I just installed the Anomaly Surveyor contract pack yesterday and one of my first missions involved going to a location close to the KSC, the abandoned airfield. Well, it has to be it, I guessed. No rocketing around that time, we'll have to fly there with a plane. Jeb swiftly hopped into my previously designed early career plane and took off (forgetting to embark Bill and Bob, but we won't need to reset experiment anyway, isn't it). I could have practiced my landing, but thought you know what, I might as well try and land there, if I get tired of failing, I'll parachute Jeb and the contract will be a success anyway.

Against all odds and after a couple of tries, I actually manage to land there with only a little trip outside the runway!

I taxied there, obviously

Ok, great! Amazing achievement, I should call it a day and recover the plane, right? But I have quite a bit of fuel left (randomly added to balance the airplane) and I want to keep going, I can do that, it's easy now ^{I'm not at all overconfident}! So where is the next anomaly? There's one quite close on the other side of the KSC and one about 600 km south east. Let's go for the latter, I want to try out a long, high altitude flight. So I accept the contract and here we go.

Do you have time to talk about scatterer?

Totally anticipated it would be night time when I arrive and not at all cheating with the luminosity with Planetshine

Oh, mission control must have forgotten the part where the Monolith is on top of a huge mountain peak... What do I do now? Land in the highlands and attempt to climb? That would take days. Abort and go back to KSC? I might not have enough fuel and how disappointing... No. There is only one thing to do in that situation with Jeb piloting and that crest on the right looks like a perfect, smooth and leveled runway!

I do not want to miss and fall into that...

Here we go, slow and steady. By that time, I learnt there actually is a trim in (stock!) KSP, it should be feasible. The secret recipe was to lower the throttle and play with it and the flaps position for speed control (I would inevitably stall at flaps 3 even at full throttle) and to set the elevators control deflect to very high (30 instead of 7 with my settings) in order to be able to touch the ground parallel to the slope with a huge pitch inclination just at the limit of stalling.

Perfect landing! Nothing wrong, nothing special to see, the left wing and the tail were removed for the sake of parking stability on the slope.

Aaaand we made it! A gentle touchdown under 50 m/s at a 30° pitch on a 30° slope, followed by a gentle braking with no slipping, no destroying half the plane or anything! And on the first try, not at all after a few dozen attempts!

Totally unrelated pictures

All and all, I learnt a lot today. I definitely will be flying more often with FAR and am considering giving GAP a try. Any other recommendation from FAR users?

Yes, Jeb, you can go home, now.

Edited February 6, 2019 by PunkyFickle

[PunkyFickle]

Damn you, mission control.

[Loskene]

Yep, found that one out the hard way too last time I tried anomaly surveyor. Ended up building a plane with a huge wing area and overpowered control authority specifically for landing on mountaintops with not a lot of "runway" space. Though I also had to strike a balance between lift and drag since many of these anomalies are quite a long distance from the KSC, and even a small speed difference makes for quite a change in travel time. We basically need planes that are stable at both supersonic and near-stall speeds. Maybe a non-janky stock swing-wing implementation would be good for this.

[PunkyFickle]

49 minutes ago, Loskene said:

We basically need planes that are stable at both supersonic and near-stall speeds. Maybe a non-janky stock swing-wing implementation would be good for this.

I don't mind spending 10 min at 3-4 times speed to cross a quarter of Kerbin's circumference at 250 m/s. It's not that long and there is plenty to do if you have mods like RPM or SCANSat. Or you can just enjoy the scenery.

By the way I managed to land next to the desert anomaly (no pictures > no spoil) on the first attempt! There is flat terrain there, though. First attempt for the northern one too. I guess I can now land.

Edited February 8, 2019 by PunkyFickle

[Loskene]

Aha, I see you're far more trusting of physical timewarp than I am.

[taniwha]

Nicely done. Landing with FAR is a challenge at the best of times (especially with stock wings and control surfaces), let alone at the top of a mountain (hey, Jeb could walk away, perfect landing).

Space planes can be very difficult due to the need to make them sleek and thus not have as much lift as a glider-style plane with similar mass/area. Here's my attempts (warning: long despite speedup (and the audio is sped up too, also the last 10 or so minutes wound up black. not sure what happened, but nothing lost):

 

Something I have learned about control surfaces (this applies to my glider-style plane):

• Ailerons of about 1/2 wing span and about 1/3 chord give good roll authority.
• Flaps of similar dimensions work well (my plane lifts off the runway with no input!)
• Spoilers with same dimensions are nice, too. (how? I have the spoilers and flaps overlapping).
• An all-moving tail-plane does wonders for Lift/Drag.
• Moar tail fin (enhanced yaw stability leads to enhanced roll stability which leads to enhanced yaw stability...).
• Procedural wings make the above easy
• Try to have your dry and wet CoM in the same place. This can be very difficult.

 

[PunkyFickle]

26 minutes ago, Loskene said:

Aha, I see you're far more trusting of physical timewarp than I am.

I pay close attention and 3 times is surprisingly stable at subsonic speeds. You just have to fiddle with the trim a bit sometimes to correct my trajectory.

16 minutes ago, taniwha said:

Space planes can be very difficult due to the need to make them sleek and thus not have as much lift as a glider-style plane with similar mass/area.

Yep, didn't venture into the grim world of supersonic planes yet... I reckon those are gonna be a tough times. I'll make good use of your advices, though.

44 minutes ago, taniwha said:

Here's my attempts

The sped up video makes it difficult to catch the details, but here are some stuff I managed to catch :

• Nice flight HUD. Which mod is that?
• Your approaches seem correct, although you go quite fast at the beginning, but you cannot do otherwise not to stall with those wings, I guess.
• I can't see you ever fiddling with the flaps. Are you confident in your sweet spot? You might want to test different deflection control settings to get to a stable lift at low speed. Never used spoilers, though.
• Something bothers me a lot, you always crash after touchdown and I don't see you ever braking. You eventually stop when you don't crash, though, so I guess that you break on your joystick without the icon to light up, right? Anyway, try reducing the friction of the brake of your front wheel, that might prevent the barrel rolls as this will allow it to slip instead of attempting to oversteer the plane and bring it in a position where it is prone to banking. (In my experience, plane wheels are extremely prone to oversteering with a joystick, and you can't reduce their sensitivity)
• Fixing the steering on your rear wheels was also very necessary!
• Also, you might want to consider adding a drag chute if you use RealChute. I know, it's not very honorable, but it might save some trouble for heavy and fast shuttles.
• Can you edit the files and load them while in game? Don't you have to restart it? Has my whole life been a lie?

[PunkyFickle]

Another perfectly levelled runway. Guess I can land, now.

[taniwha]

@PunkyFickle  Yeah, the speedup does hide details, but the purpose of the video was to show the value of not giving up, and what practice really is (I did it for my daughter and decided to upload it).

The hud mod is Kerbal Flight Indicators.

That plane had no flaps. I don't see how flaps would work on a delta-wing plane (ie, one with no tail-plane), and I haven't figured out slats (ones on the leading edge).

I have brake pedals (thrustmaster t16000m + throttle & pedals) giving me linear braking (custom input mod, not generally available because it's currently linux-only (help wanted ))

Most of my problems were due to bouncing, thus the fiddling with the spring setting. Braking caused problems only when I failed to steer straight using my feet (I was trying to feather the brakes). I think many of the deceleration problems were caused by me twisting my stick slightly (that's bound to wheel steer) and the rear wheels having steering enabled (thus over-steering).

I was editing the quicksave, not the part config files. So no, your life has not been a lie (at least with respect to KSP). Editing part configs or even the craft file would do no good as the full vessel details are saved (meaning you can launch a vessel, go back to the editor, edit that vessel, launch that one, and have two actually different vessels in flight). I suggest taking a look in a save file (persistent.sfs or quicksave.sfs), quite enlightening.

And yes, I considered a chute, but... that practice payed off. I tried landing (from orbit) my Tobineko again just the other night and got it first try (after a few aborted approaches to the runway). It's a Juno+LV909 spaceplane and thus has to be landed at high speed. Even with the default settings on the suspension (the plane was built in KSP 1.3.1 thus spring and damper were not tweakable), I had no trouble other than some mild bounce while braking.

And finally, good job landing in a place like that!

Oh, and if you want, I can try to find a way to get you the full video at normal speed (unfortuantely, the VOD has fallen off twitch (taniwhaqf if you ever want to check my channel)).

[PunkyFickle]

• Thank you. In hindsight, I find it too intrusive and enjoy switching to IVA for precise maneuvers (with RPM giving me so much info).
• Well, you do have canards, wouldn't they work as well? Besides, FAR lets you set your elevons as flaps too. I didn't test that yet nor thought about it too much, but I imagine that it wouldn't go wrong if well configured, I guess.
• But it doesn't trigger the in-game breaks, does it? The icon doesn't light up. How does it work? Because it really seems like not braking enough after touchdown is a real problem of your landings. Or your brakes' friction is not high enough.
• About twisting your stick, since you have pedals for the yaw, you might want to set a bigger deadzone to avoid those unwanted steerings. Or reduce its sensitivity (or holding it more gently). Moving your wheel that steers at high speed is a pretty bad idea. Why don't you map it to your rudder pedals, by the way? That's how it is in general, isn't it?
• Well, being able to edit the persistent.sfs is already something. It makes sense, since the game reloads from it directly.
• Yes, I'd probably spend several days ragingly attempting to land my shuttle or whatever before eventually resorting to using a chute if I ever do.
• Thank you, but I spent so much time on it that my plane is very well balanced now and that I am very used to it. It will probably be a (delightful) pain to build and learn another one, now!
• No, that's fine, it was informative to watch like that, but I wouldn't spend hours feeling the pain of repeatedly not managing to land a plane over and over. I do that on my own well enough! 

[taniwha]

I'd kind of hoped you' d not want to see the full video, that's a lot to upload somewhere.

As for the bakes: they directly set the brakeInput field of brakes (and actually set statusLight appropriately). The brake icon in the altimiter display is for the action group.

Since that video, I have further improved my custom joystick mod fixing a few bugs (including some dead-zone issues) and adding power curves to analog inputs, and the ability to bind to custom action groups (eg, 1-0 on the keyboard). The power curves I used for steering my rover in my Duna trek (VODs still on twitch), and the action groups for flaps on my glider-style plane... what a difference :) (hidden in the vods somewhere). I'm considering adding the curves to my PYR inputs, too, as currently I barely move the stick when flying normally.

KerbalFlightIndicators is quite nice in IVA, too. It made a HUGE difference in that Duna trek: driving from IVA (especially with KFI active) gave me a much better feel of what was going on and so I had fewer crashes. 30m/s from external view: too slow, need to spee*crash*, 30m/s from IVA: aieeee, we're all gonna die, slow down! (I found that 20m/s was usually a good speed, unless the terrain was really bad). Also, just being able to see how much I was side-slipping helped me correct earlier and avoid some accidents.

[steve_v]

14 hours ago, taniwha said:

custom input mod, not generally available because it's currently linux-only

Err, I'm runinng GNU/Linux, can I convince you to share?

[taniwha]

@steve_v: https://github.com/taniwha/AdvancedInput

The only reasons I haven't made a lot of noise about it on the forums is the linux-only bit and the fact that the UI is not there yet. I am very happy to share it

You will need to build it yourself, but all you need is sh/bash (not sure which is used), git, make, gcc, mono and inkscape (for the app launcher button icon). If you have trouble, let me know.

make KSPDIR=<path to KSP_linux> install

Note that currently, the configs are loaded at KSP load time.and are not YET editable in-game (WIP). The configs are in Data in the source tree, and GameData/AdvancedInput/Plugins/PluginData/AdvancedInput when installed). There are sample setups for saitek x52 (device retired), thrustmaster t16000m, thrustmaster twcs throttle, and xbox 360 wireless (never actually used).

Edit: oh, and you might want to consider making all your js* devices unreadable: Unity in KSP 1.1-1.3.1 would crash when pressing a JS button in the 20+ range, and in KSP 1.5.1, Unity crashes just reading the name of my thrustmaster.

Edited February 12, 2019 by taniwha

[PunkyFickle]

52 minutes ago, taniwha said:

Unity crashes just reading the name of my thrustmaster.

"I can't handle that!" *Heart attack* Poor Unity...

6 hours ago, taniwha said:

The brake icon in the altimiter display is for the action group.

Oh, I didn't know that. But it makes a lot of sense. So you bypass the in-game key mapping.

I really think that they should add the option to set power curves in the game. It's a must have as long as you support joystick usage. About switching them between vehicle types, there are enough options for wheels and control surfaces not to have to mess with your input API, 

6 hours ago, taniwha said:

KerbalFlightIndicators is quite nice in IVA, too. It made a HUGE difference in that Duna trek: driving from IVA (especially with KFI active) gave me a much better feel of what was going on and so I had fewer crashes.

Yes, I am WAY more cautious while flying in IVA! Don't you use RasterPropMonitor, by the way? It adds a lot to IVAs and doesn't make it like a giant yellow handlebar is flying ahead of you...

The development just stopped two weeks ago, because the person how was maintaining it is moving to his own similar project (MOARdV's Avionics Systems), but it's a sturdy and broadly used (and thus well maintained) mod that I'd recommend you to check if you didn't try it and enjoy IVAs.

[taniwha]

I do not like RPM, its aesthetic does not suit my tastes. I have used it, and even done an IVA landing on Minmus using it, but it's just not for me. I find KFI to be nicely unobtrusive, and more importantly, I spend more time looking out the window.

Anyway, each to their own. The beauty of KSP mods is they allow each of us to play our own KSP :)

[steve_v]

4 hours ago, taniwha said:

You will need to build it yourself

Unlikely to be a problem, I've been compiling other peoples code for a long time.  Sometimes I even compile my own, but that's strictly for slow days.
Thanks for it not being a VS project with a bunch of batch files and postbuild events I have to eviscerate, those are a pain in the ass.

I'll be sure to have fun with it.

4 hours ago, taniwha said:

you might want to consider making all your js* devices unreadable

I think I still have a namespace-magic wrapper around here somewhere, it should do for hiding those device nodes.
 

1 hour ago, PunkyFickle said:

Poor Unity

Unity's input handling on GNU/Linux is a disaster and has been for a long time. Frankly, the new one looks to be a step backwards.

[taniwha]

@steve_v do you think I should make a thread for AI despite it not being anywhere near ready?

[PunkyFickle]

19 minutes ago, taniwha said:

I do not like RPM, its aesthetic does not suit my tastes. I have used it, and even done an IVA landing on Minmus using it, but it's just not for me. I find KFI to be nicely unobtrusive, and more importantly, I spend more time looking out the window.

Anyway, each to their own. The beauty of KSP mods is they allow each of us to play our own KSP

Sure! I won't fight over that. However what I really find useful are not so much what you get on the screens (although the SCANSat map is amusing), but this HUD thingy with tons of essential informations you sometimes don't get anywhere else, like the trim % or pitch and roll angles, your engine thrust and vertical speed.

That being said, MOARdV's new WIP looks very promising.

[steve_v]

20 hours ago, taniwha said:

do you think I should make a thread for AI despite it not being anywhere near ready?

Dunno TBH. If it was mine I would, it's rather good.
I didn't have any problems building or setting it up, but annoying questions are inevitable if you make a thread... I guess it comes down whether or not you can be bothered dealing with users.

[taniwha]

@steve_v In that case, maybe I should.  Who knows, somebody who knows a thing or two about mac or windows joysticks might show up.

And I'm glad you like it :)

Edited February 13, 2019 by taniwha

[steve_v]

4 minutes ago, taniwha said:

I'm glad you like it

Of course I like it. It works well, and it does it with a nice clean C interface that makes proper use of the input subsystem. What's not to like.
 

How Unity can make such a hash of input handling really does baffle me. Even with SDL middleware in the mix they still manage to screw it up.
 

[taniwha]

Anyway, I've gone and released it:

 

[PunkyFickle]

1 hour ago, taniwha said:

Anyway, I've gone and released it:

Good job! I won't be testing it as I'm only running Widows for now, but the number of supported inputs and clever features as well as the integration to the game's framework are encouraging signs.

There are a few typos in your post, by the way. You should proofread it (again).