Hodo

My suggestion. Just place the B9 invisible struts on the load near the back of the load attaching it to the cargo bay. This is what I do with most of my large cargoes.

SABREs top out at just over Mach 5 before they start to lose power so that isn't the main issue. The thing I can see you are having is a loss of pitch control at those speeds. You are dealing with a serious amount of loss of lift at those speeds. Additional wings isn't going to solve this. I am sure if you look at your Statistic tab in FAR you will see your CL line drop drastically the faster you go. I also imagine your CoL is shifting back further away from the CoM of the craft at hypersonic speeds. But there are two ways of fixing this issue. 1- Redesign and scrap the current design and add more control surfaces and shift the CoL closer to the CoM. 2- Just add canards to the nose of the craft set to only pitch and a very limited control angle. I have a bit of experience with SSTOs in FAR and large SSTOs expecially.

One suggestion that would help with the look a bit. Move the wingtip pylons a bit more forward on the wings. The wing mounts are set so the missiles more than 50% ahead of the wingtips. And the twin nose guns, you can drop one and place it in the nose top balance this with the ammo going under it tucked inside of the craft. Great looking craft though, one of the best F/A-18s out there.

You mean Firespitter.

Yeah somethings changed. And I am not sure what is happenning with your craft but I am still able to make aircraft that can pulled 10-15Gs subsonic and around 7-9Gs supersonic, with aero-failures ON.

This looks like something I can use. I could have used it a few months ago for a challenge.... this looks like it would work much better then my crane.

What are describing is not an aileron. It is a Canard or an Elevator. Ailerons control roll Elevators and Canards control pitch Rudder controls yaw. Eleverons are a combination of an Aileron and Elevator. As Rocketeer said, right click on the control surface in the SPH and set the job for it. There is a guide in this sub forum for basic setup of an aircraft.

I am an ID10-T for forgetting to add the craft file..lol. I added it to my post, been really busy the past few days just finished moving last week and still getting things settled around the house.

The easiest thing to do is to just attach struts to the rear of the cargo load that you have there so it is supported at the back. Otherwise it will fall through and or wobble everywhere making the craft nearly impossible to control.

The issue is a fuel flow problem. I have encountered it before with some of my larger multi-engine ships. The trick is to add additional fuel lines between the engine nacells so you have more cross feeding. At least that is what worked for me in the past. I haven't built anything like that in a long long time.

I am so downloading this when I get home.

Unfortunately no other alternatives. My only other suggestion is to reduce the control range of the control surfaces that will help reduce some of the oscilations from the SAS. As for your craft suddenly losing control when you switch over to rockets, sounds like you are having an action group failure, where it is not activating everything at the sametime. This is usually caused by moving a paired part after you set the action group. Go back into your action group settings in the SPH and click on the action group that engine is set to, then click on each on of the engines individualy and see if they are set to action group. Hope that helps with that a bit.

There was a mod that I still use by Regex called the PID, it let you limit the force of the SAS module. It is quite handy when you fly with SAS on. You can also reduce this oscilation by reducing the max control angles of the control surfaces. Bring them down to about half of the default settings.

Or you can do like this. This is a VERY old craft I built back in .21. It was a VTOL and was able to cary a rover in its cargo bay.

It sounds like that mod is drawing to much memory and pushing over the 3.4GB of RAM limit that 32bit has. Try forcing the game to run in OpenGL and see if that brings the memory foot print down a bit. But honestly I think it is that mod that is the issue.

My latest project. F/A-106 Thundergod F/A-106 is armed with a 30mm GAU8, and up to 20klbs of ordnance, designed for the ground attack role. F/A-106A is armed with a pair of 20mm M61 Vulcans and up to 20klbs of ordnance, a multi-role fighter.

This is why I said, it depends on what you are trying to launch. If it is something smallish and light you can get away with LH2+LOx.

The problem you run into with IR is the wobble. If you strut them it wont rotate, if you dont, they wont stay straight.

Ok finally my entry.... In- FAR Best sporty pleasure craft Best use of B9 parts Best-looking craft FA-106A Thundergod Mods-B9, Procedural Wings, Procedural parts, Real Chutes, BD Armoury, FAR, DRE, TAC Fuel Balancer. Flight profile- Set Fuel Balancer to balance liquid and Oxidizer, and out of the B9 fuselage. Climb at best rate to 11km, or around 35deg. At 11km bring nose down to 10-11deg and accelerate to mach 5+. At mach 5 switch SABRE engines over to closed cycle and pitch up to 20 deg and climb to desired orbital AP. Circularize as normal. Re-entry profile, set nose up to 2-7 deg and deploy air brakes. Landing speed is 150-160knts (80m/s) once the wheels touch the ground activate next stage and it will deploy the drag chute for landing. You can also use the wheel brakes to bring your stopping distance down to less than 1/8th of the runway. Action groups. 1-Toggle SABRE engines on off. 2-Toggle SABRE engine mode. 3-Weapons Manager Fire 4-Weapons Manager Next 5-Weapons Manager Previous 6-Drop Countermeasure 7-OPEN 8-Toggle Air brakes 9-OPEN 10-OPEN EDIT I am an idiot and forgot to post the craft file..... https://www.dropbox.com/s/x663usdqhi57zo9/FA-106A%20Thundergod.craft?dl=0

You mean Infernal Robotics, KAS is just the plugin that lets you attach and remove parts. That design I posted was something that had way more engines than it needed just incase it had a heavy load. I have some that only have 2 engines, others that have up to 20. The trick is mainly about balancing the CoM and Vertical CoT. Test out with smaller designs first and figure out what works for you and then scale it up.

VTOL and STOVL SSTOs of this type aren't to terrably difficult. The trick is making sure your CoM and Vertical CoT are perfectly inline no matter the fuel load or cargo load. This may require a mod like TAC fuel balancer. But that craft it wouldn't be to hard to do it with. B9 has some VTOL rocket engines that work perfect for most non-oxygen planetary landings. I have used them quite a bit in the past. This could haul about 72 tons STOVL or 36 tons VTOL into a 100x100 orbit. You can see that the engines are place far enough out to provide a wide thrust base, and they center the center of thrust through the CoM.

Alshain is dead on with his suggestions. On a side note, I don't think that craft will make it to Duna and back with its fuel load. The SABER-M engines are not the most efficient engines in space. Note how this craft uses LV-1N angines in space to do most of its orbital maneuvers. That craft when I had it could haul 120 tons into an orbit of 100km x 100km, unfortunately I no longer have that craft file. I am currently rebuilding my career mode to get back to where I can build another monster lifter.

It is because your CoT when you are doing your orbital maneuvers is above your CoM. This is causing your craft to push the nose down. If you angle the OMS engines so they push through the CoM, you will push the craft at an angle through space. This is what the real space shuttle did in space. The other option is to move your OMS engines down inline with the CoM.

As Wanderfound said about the CoM in relation to your cargo bay. I often add empty tanks to my craft and use TAC fuel balancer to shift the CoM around in flight to maintain a very even flight profile at all speeds. This takes a bit of practice and is way overly complex and there is probably a plugin that would make that job easier. Once you get the hang of it, you will find that you can get away with more and more wild designs. Things you never thought that should work actually work, and others will fail in fantastic ways.

1- Cryo tanks are great for fuels that require a low temp before they begin to boil off. LH2 is one that comes to mind. If it isn't kept below a certain temp it will begin to boil off. In RF this means that you will begin to lose fuel out of that tank if it goes above that temp. For non-cryogenic fuels you can use any other fuel tank. 2-You have to EVA to install them into the engine after you have used the ignition on that engine. 3-Some engines require a pressurized system in order to work. If you have a fuel tank that is not pressurized and an engine that requires a pressurized system you will not be able to start that engine no matter the g forces. 4-LH2+LOx is a good basic first stage fuel, so is Kerosene and LOx. It depends on what you are trying to launch. 5- Not impossible, just exteremly difficult to do. You most likely will not be able to do it in one launch. The real mission to Mars was planned to be launched in stages and docked together in orbit, refueled then launched to Mars. With a refueling tank already in orbit around Mars and a resupply module there sent remotely months prior to the manned mission. All reasonable questions by the way.