Too fast landings

[bartekkru99]

I've just finished my new fighter jet, it's great to fly around, it's fast and very maneuverable and cool, but there's one issue with it - I can't really land it, because speeds are too high, I think, you know what it means? Oh and I'm using FAR.

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Edited October 24, 2014 by bartekkru99

[capi3101]

So, I'm assuming the question is one of "how do I land this thing". For starters, going 210 m/s at a 65 degree angle into the ground is probably not how you're going to want to do it. Though that is excellent lithobraking technique.

Sarcasm aside, I'll edit this post to give you some pointers when I get a chance.

EDIT: Okay. Well...it's difficult to say with the UI missing from most of the shots, but it looks like you don't have much issues with alignment. So I'm going to go with your glide-slope is too steep. Lemme ask: what's the craft's take off speed?

Here's what you want to do - if you're not using a landing assistance mod like NavUtilities, you can set a flag or a powered probe core right off the two ends of the runway (right where the terrain color changes to that darker shade of green). Line them up as best you can with the center of the runway. Once those two are in place, set another one exactly one kilometer to the one on the west side. You wind up with a primitive ILS that way. The three markers should help with alignment. For glide slope, you want to be looking occasionally at your distance to the one at the end of the runway you're approaching from (if you're landing on 09, you want the marker on the west end of the runway; you want the one on the east side if you're landing on 27). Take that distance and multiply it by 100, plus 100; the end result is what you want your altimeter to read, give or take. If your reading is higher, you're too high and need to increase your rate of descent. If your reading is lower, you're too low and need to decrease your rate of ascent. Your friend here is the rate of descent meter to the right side of your altimeter. Obviously you don't want to be flying full blast when you're touching down; throttle back as you make your final approach - real airplanes barely have any throttle at this point in their flight as it is. Once you're within about two kilometers or so, you don't want to be descending much faster than five meters per second or so. When you get over the runway, kill your throttle, bring your nose up (to no more than five degrees over the horizon - and watch this, because it'd be really easy to start ascending again if you overdo it) and hopefully you'll touch down gently.

Horizontal speed? 60-80 is a good rule at touchdown, but by no means absolutely necessary.

Edited October 17, 2014 by capi3101

[bartekkru99]

So, I'm assuming the question is one of "how do I land this thing". For starters, going 210 m/s at a 65 degree angle into the ground is probably not how you're going to want to do it. Though that is excellent lithobraking technique.

Sarcasm aside, I'll edit this post to give you some pointers when I get a chance.

It can't really slow down it's min. speed is 60m/s, when going straight up... But it is pretty hard to land on the runway when going upwards...

[Epthelyn]

Embed Imgur albums with only the album code, in your case:

[img UR]QGo5O[/img UR]

Remove the spaces.

Anyway, you appear to have landed at 206m/s. That's not going to end well for any plane.

[bartekkru99]

Embed Imgur albums with only the album code, in your case:

[img UR]QGo5O[/img UR]

Remove the spaces.

Anyway, you appear to have landed at 206m/s. That's not going to end well for any plane.

As I said, I can't slow it down.

[capi3101]

It's a fighter replica, right? Have you considered using drag chutes? It might look like drek, but a quad of radial chutes right there along the tail fired as you pass over the runway could help bring your speed down. Drogues might do the trick too in your case but they'd require more tweaking to your design.

[Franklin]

It can't really slow down it's min. speed is 60m/s, when going straight up... But it is pretty hard to land on the runway when going upwards...

Yeah, with the lack of air brakes currently (hope you're listening, Squad) slowing down in FAR can be a tedium. Most recommend washing off speed with an S pattern, and don't be afraid to pull up and circle back around if your landing seems sketchy.

My tips for slowing the hell down in FAR:

Radial chutes set to not fully deploy until you're basically on the ground. These should slow you down considerably, but you don't want them to ever fully deploy. I think you may be able to set them to cut to an action group, but I'm not certain.

Edit: Remember, a deployed parachute will cut automatically during descent if propulsion is used to increase vertical speed past zero.

Forward-facing tiny engines set to super low thrust that you can toggle with an action group. These will have the same effect, but your "CoL behind CoM" logic with your design gets tossed with these so I find they can be squirrely.

Edited October 17, 2014 by Franklin

[Norpo]

I haven't used spaceplanes much, so take this all with a grain of salt. I take no responsibility for VABs destroyed, kerbals lost, or kraken enraged by following this advice.

It can't really slow down it's min. speed is 60m/s, when going straight up... But it is pretty hard to land on the runway when going upwards...

Even when at low throttle? You shouldn't be at max throttle all the time, and if you are, then you should lower throttle at LEAST a minute before you land.

As a general rule (this is for stock, but I think it may work for FAR as well), turn up so the wings are producing a lot of drag. Generally, just keep throttle off (or very low) when you're landing, and you should be good. With 260 m/s, you can just glide to the runway provided your wings are good enough. (For FAR, if you go too much up, then you may get your wings torn off thru aerodynamic failure, or get in a stall. Don't go all the way up, I speak from vague memories using FAR)

By the time you've killed enough speed, you should be coming in at around 120 m/s, tops. Land straight horizontally, then when your landing gear have all touched the ground, hold down B (to brake). You should be slowing down.

tl;dr don't have your jet engines on all the time, I may be wrong.

[Franklin]

Maybe you could use balanced Elevons so they act as air brakes? Can you set them to "reverse controls" like you can rover wheels so 2 pitch down and 2 pitch up at the same time? I've never tried that.

[bartekkru99]

I haven't used spaceplanes much, so take this all with a grain of salt. I take no responsibility for VABs destroyed, kerbals lost, or kraken enraged by following this advice.

Even when at low throttle? You shouldn't be at max throttle all the time, and if you are, then you should lower throttle at LEAST a minute before you land.

As a general rule (this is for stock, but I think it may work for FAR as well), turn up so the wings are producing a lot of drag. Generally, just keep throttle off (or very low) when you're landing, and you should be good. With 260 m/s, you can just glide to the runway provided your wings are good enough. (For FAR, if you go too much up, then you may get your wings torn off thru aerodynamic failure, or get in a stall. Don't go all the way up, I speak from vague memories using FAR)

By the time you've killed enough speed, you should be coming in at around 120 m/s, tops. Land straight horizontally, then when your landing gear have all touched the ground, hold down B (to brake). You should be slowing down.

tl;dr don't have your jet engines on all the time, I may be wrong.

Yeah I'm using FAR. And does someone knows how to turn flaps on with FAR? There's an option to use a control surface as a flap or spoiler when you right click at it...

[Greenfire32]

I don't use FAR so I cant tell you exactly what to do, but it feels like you're not starting your glide far back enough. Cut the engines totally (or very minimal thrust) farther away from the runway then you do now.

Also, flying in an "S" pattern should cut your horizontal speed QUITE a bit, so try that too.

All in all, it seems like it's just an issue of getting to know your craft and working with it instead of ignoring your craft and redesigning it.

[Hodo]

Yeah I'm using FAR. And does someone knows how to turn flaps on with FAR? There's an option to use a control surface as a flap or spoiler when you right click at it...

Ok quite simply the craft in the OP is traveling to fast to land, you should look at a longer shallower landing approach at about 2-3deg. You were trying to land at over 460mph! That is nearly .6 mach, F-15s cruise at those speeds. Flaps help with the low speed landing approach and the take off. I know I usually line up for my landings about 10-20km out from the runway. Also you may want to add an airbrake or spoiler of some type on the craft to get it to slow down. Lastly disable the nose gear brakes in your action groups, or it will cause your craft to flip over or lose control under breaking.

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Note this crafts landing speeds and the use of flaps for slow landing speeds. Aside the fact that it is a swing wing design.

Oh and the posting of imgur albums dont put the #1 at the end of the link, just post this....

[ imgur ] 5bj0i [ / imgur]

no spaces, that is the code to my album I just posted.

Edited October 17, 2014 by Hodo

[bartekkru99]

Does somebody know, how to turn the flaps on?

[Martin0]

Does somebody know, how to turn the flaps on?

1- right click the control surfaces you want to use as a flap and click the "use as flap" blue button

2- go to the action groups tab and assign the control surfaces to two action groups (one to raise the flaps, the other to lower them)

You can also use control surfaces as spoilers (like flaps, right click -> use as spoiler), those activate when braking andare used to slow you down.

[bartekkru99]

1- right click the control surfaces you want to use as a flap and click the "use as flap" blue button

2- go to the action groups tab and assign the control surfaces to two action groups (one to raise the flaps, the other to lower them)

You can also use control surfaces as spoilers (like flaps, right click -> use as spoiler), those activate when braking andare used to slow you down.

Thanks, I knew how to turn it into a flap, but I didn't know how to use it.

[GoSlash27]

From the pictures, your problem has already been identified:

You're trying to land at full throttle.

Using flaps and spoilers will reduce the speed at which you can make a gentle descent, but you have to throttle back to get it slow enough to land.

Landing requires grasping a new concept; angle of attack (or "alpha"). It is the angle between where you're pointed and where you're going. When you're in a shallow descent with your prograde marker about 5 degrees below your nose pipper, you're in a proper attitude and speed for landing.

I recommend practicing that a few kilometers up to get a feel for how the aircraft handles at that lower speed. Just set it in level flight and throttle back until the prograde marker falls 5 degrees below the nose. Then add enough throttle to hold that and practice flying it.

No sudden maneuvers and nice, gentle banking, or else you will put it in a stall. To recover from that, get the nose down immediately and add throttle, then fly out of it.

Get used to flying the plane in this state, because the last thing you want to do is stall it just above the ground where you're out of altitude and time to recover.

Good luck!

-Slashy

[bartekkru99]

From the pictures, your problem has already been identified:

You're trying to land at full throttle.

Using flaps and spoilers will reduce the speed at which you can make a gentle descent, but you have to throttle back to get it slow enough to land.

Landing requires grasping a new concept; angle of attack (or "alpha"). It is the angle between where you're pointed and where you're going. When you're in a shallow descent with your prograde marker about 5 degrees below your nose pipper, you're in a proper attitude and speed for landing.

I recommend practicing that a few kilometers up to get a feel for how the aircraft handles at that lower speed. Just set it in level flight and throttle back until the prograde marker falls 5 degrees below the nose. Then add enough throttle to hold that and practice flying it.

No sudden maneuvers and nice, gentle banking, or else you will put it in a stall. To recover from that, get the nose down immediately and add throttle, then fly out of it.

Get used to flying the plane in this state, because the last thing you want to do is stall it just above the ground where you're out of altitude and time to recover.

Good luck!

-Slashy

uhmmmm.... I landed with my engines turned off. And it doesn't start to spin even when doing agressive maneuvers, it can't just slow down :/

[GoSlash27]

uhmmmm.... I landed with my engines turned off. And it doesn't start to spin even when doing agressive maneuvers, it can't just slow down :/

That can't be the case. The first image (just before you crashed into the satellite dish) shows you in a final approach attitude and speed. Actually *slower* than optimal.

You *can* slow down, 'cuz you did it in that pic. All you have to do is do that into the runway instead of the buildings.

I swear I don't mean to be mean when I say this, but judging from the pictures it looks like the main problem is that you haven't yet learned how to fly. Not just jamming the throttles and maneuvering around, but actually *flying*. Once you do that, you shouldn't have any problem sticking that landing.

Best,

-Slashy

Edited October 18, 2014 by GoSlash27

[Wavechaser]

Go get B9, and use its airbreaks.

[Jovus]

Take it from another guy who had a whole world of trouble with landing until just recently: right now you don't want airbrakes. Airbrakes steepen your glide slope, and your glide slope is one of your big issues right now. You want flaps, and put them close to your pitch axis so they don't force the nose up.

As to the question of slowing down - you can do it. There are lots of ways to slow down with FAR. The #1 thing to remember is to cut your throttle completely, and then tap Shift just enough that you have the tiniest sliver active for thrust vectoring. Then, remember, nosing down will (generally) speed you up, while nosing up will (generally) slow you down. At that point it's a tradeoff between altitude and speed, which can be difficult because you want to be going low and slow to land. Come in too low too early, and you're going too fast. Come in too high too late, and you'll hit stall speed, dive, and crash.

As a very rough rule of thumb, I've found you need to be going less than 125 m/s when you break below 1000m on your final approach, but it very much depends on the airframe. What doesn't depend on the airframe is paying attention to your glide slope: Generally, when you're going to touch down, if your prograde marker is more than 5 degrees below the horizon, you're going to die. Check your Vertical Speed Indicator (the circular dial next to your altimeter at the top of the screen) and if it's about 10m/s you're going to die. (And if it's close, you're going to have a very rough time.)

You've already been given some advice on how to slow down. S turns (or full circles) work, as do flaps and spoilers. Or you can dive and rise, dive and rise, if you're more comfortable with that. In any case, start your approach far out - about halfway to the mountains, or almost in line with the island runway. It takes a longtime to slow down in FAR.

And if, in the final analysis, your plane truly can't slow down in the sense that its stall speed is higher than 125m/s, then go back to the SPH and change things, because you haven't built a plane, you've built a flying execution device.

[bartekkru99]

Does anybody wants to see my new thred with my creations?

[MegaFlop10]

Could you send a .craft file? I'd like to see what's up.

Also, try adding Sepatrons to the plane to slow down more at landing.

[bartekkru99]

http://forum.kerbalspaceprogram.com/threads/97297-BK99-s-Military-Crafts-Library

[MegaFlop10]

http://forum.kerbalspaceprogram.com/threads/97297-BK99-s-Military-Crafts-Library

Do I really have to create an account to download it?

*is angry*

So for some reason it just won't let me make one, so could you host it on dropbox instead?

[bartekkru99]

Do I really have to create an account to download it?

*is angry*

So for some reason it just won't let me make one, so could you host it on dropbox instead?

I think, that I might post it on Curseforge, but now, I'm studying for a history exam, sorry...

EDIT: or on Github...

http://kerbal.curseforge.com/shareables/225001-fp-17-striking-bat

Edited October 19, 2014 by bartekkru99