[Modded][FAR][B9] - Cargo Spaceplane that can glide to safe landing?

[Peppe]

latest versions of everything.

Saw Scott Manley land stuff without wings even... I have wings and still can't land my cargo plane

First non fighter type plane using FAR and b9 stuff.

My goal for the vehicle is to not need/use fuel after de-orbiting. S2 cargo bay -- payload capacity not determined -- empty weight ~25 tons. Is there a landing path or technique to learn to land big flying bricks?

Also SAS causes crazy wobble/oscillation... been flying with it off. Sign of a design issue or is sas no good for planes?

Been adding wings/control surface and feel like i have better control of the plane all the up to the crash landing

Feel like I am Missing some way to get under 100m/s and stay stable/level for safe landing.

Tips?

Edited December 25, 2013 by Peppe

[InterCity]

As you probably know, aircraft fly because of air flow around their wings. If you can't get the aircraft to land in horizontal position, try adding either more engine power, or more wings. I recommend using the wings though, because more speed means more runway required.

And check your landing weight. You may find the craft too heavy.

P.S. How did you get it airborne?

Edited December 25, 2013 by InterCity
Curiosity

[Col_Jessep]

Is there a landing path or technique to learn to land big flying bricks?

The most important part in my opinion is to avoid stalling. Your flying brick wants to go down mostly and you have to let it more or less. If you need to pull up or yaw do it slowly and with care. I would recommend to run the engines at 10-20% until you are finished with setting up your landing approach.

Also SAS causes crazy wobble/oscillation... been flying with it off. Sign of a design issue or is sas no good for planes?

Design issue I think. A quick solution would be to press F and wait until the wobbling stops then release the F key again. Long-term you will probably need to cut back on control surfaces, disable reaction wheels in the cockpit or my personal favorite: use MOAR struts.

Been adding wings/control surface and feel like i have better control of the plane all the up to the crash landing

Feel like I am Missing some way to get under 100m/s and stay stable/level for safe landing.

You have air brakes on your wings. Ferram says they are over-powered so you might as well use them.

Toggle the air brakes with your regular landing gear brakes and use them to slow your spaceplane down before you land. Keep in mind that your spaceplane will be harder to control after breaking so don't slow down too much. 80m/s should be just fine to land.

[ib4 Ferram tells us how to do it properly ]

[Peppe]

Thanks for the tips. Getting into the air so far has not been a problem. Think the wings and the engines are reasonable for the size. If i tweak the control surfaces to smaller max numbers the ossicilations go away with SAS on... also noticed SAS only did it for some altitudes/pitch angles -- i'll try strutting everything up though, so far had no struts.

I could tweak down the starting fuel and see if it is easier to land with barebones. I guess that is about what it should be returning to the surface with.

Just slapped those airbrakes on before the screenshots. They drop speed quickly -- first time i tried them i was a little too high up and it sent me into a nose dive. Triggering them at near the last safe second seemed to work, but need to be skimming the surface, which used some engine power to maintain. Got a keyboard landing with them and took off to try again... not so lucky the second time.

Found engine power could save the day if my glide stalled and started to nose down. Maybe I should pull more/all the weight off the front, so it is easier to keep the nose up on landing -- have cockpit, structural fuselage, and mono-propellent fuselage there?

Also thought it could just be the keyboard input. Not having a flight stick i just plugged in a 360 controller and what a difference. Up and back down on the runway no less on the first try, no air brake it was like i was play Battle Field 1942 again. Landing was a little fast, so i think i'll map air brakes and other brakes to the gamepad, but so much easier to have at least a thumbstick.

If i right click a B9 control surface I can set it to 'use for flaps' and use for x? but the x is cut off. What are those and how do i trigger/map plane wide flaps and maybe air braking?

[Andrew Hansen]

To solve the SAS issue, go to the VAB and open up the Ferram Aerospace Research configuration thingomablob. Then click on the control surfaces you are using for rolling your plane (the ones on the outsides of your wings) and change the surface deflection to 10 or 5 or whatever seems to work better. You can also assign control surfaces to be used only for the roll, pitch, or yaw axis.

As far as the air brakes go, I'd recommend not using them. I tried for a while, but in FAR they're far (pun intended) less effective than in stock. Just come in for a nice, slow landing without them and turn on the brakes when you hit the ground.

A mod I would recommend to make building planes that much easier would be the RCS Build Aid mod. It has the capability of showing the dry center of mass of your plane. Make sure it is as close to the center of lift as possible. What always seems to happen to my planes is that they lift off fine, get to orbit fine (since they are spaceplanes), but when it comes time to land them, they are uncontrollable because the center of mass has shifted too much. Try moving fuel tanks around to get the center of mass to stay in more or less the same place.

Below I've attached a video from my YouTube channel in which I fly two SSTOs. The first one is well-balanced, and the second is not. It might be helpful.

Happy flying!

[Taki117]

It appears your rear landing gear are very narrow, this might have something to do with it. Also for landing winged things such as flying bricks there is

[Hodo]

latest versions of everything.

Saw Scott Manley land stuff without wings even... I have wings and still can't land my cargo plane

First non fighter type plane using FAR and b9 stuff.

My goal for the vehicle is to not need/use fuel after de-orbiting. S2 cargo bay -- payload capacity not determined -- empty weight ~25 tons. Is there a landing path or technique to learn to land big flying bricks?

Also SAS causes crazy wobble/oscillation... been flying with it off. Sign of a design issue or is sas no good for planes?

Been adding wings/control surface and feel like i have better control of the plane all the up to the crash landing

Feel like I am Missing some way to get under 100m/s and stay stable/level for safe landing.

Tips?

http://i.imgur.com/G1c7Mzj.jpg

Ok I am seeing several issues with the craft that are causing your problems.

1- your engines are below your CoM which is causing your CoT to be below the CoM which is pitching the nose up.

2- It appears you have every control surface set to do everything. Try assigning your tail elevator to pitch along with your canards. Your wing ailerons to roll and your rudder to yaw. This will help with your oscillation issue.

The other thing that is causing the oscillation is the speed at low altitude where the atmosphere is the densest. Try keeping the craft subsonic until you hit 10km altitude, then increase speed to super sonic speeds.

[Peppe]

Thanks for the feedback all. Not perfect, but took up some of Hodo's planes and back down and see I have lot more things to consider to cover all the control needs.

Deconstructing some of his planes and learning a lot. I don't know how you do it, they look so good and fly well.

[Hodo]

Thanks for the feedback all. Not perfect, but took up some of Hodo's planes and back down and see I have lot more things to consider to cover all the control needs.

Deconstructing some of his planes and learning a lot. I don't know how you do it, they look so good and fly well.

Thanks lots, and lots and lots of testing, and my girlfriend hates it.

[EatVacuum]

Ok, question was asked earlier and not answered. How do I trigger the flaps and or airbrakes. I don't need to be told not to bother using them, I know that option exists, but for the life of me, if I do want to, I don't see how to activate them. Thanks all

[Taki117]

Ok, question was asked earlier and not answered. How do I trigger the flaps and or airbrakes. I don't need to be told not to bother using them, I know that option exists, but for the life of me, if I do want to, I don't see how to activate them. Thanks all

You need to set them to the Brakes Action group. (At least that's how airbrakes work, not sure about flaps)