Problems with (my) Spaceplane(s)

[cy-one]

Sooo,

I was never good with SSTOs, buuut at least I got them working, kinda.

Now I'm trying to build an SSTO based on a mix of Mk2 and Mk3 parts.

But before even getting to the "space" part of "Spaceplane", I'm already failing at "plane".

I just took a look at the stock crafts.

Aeris 4A: CoL very slightly infront of CoM

Aeris 3A: Not an SSTO, but anyway - CoL slightly infront of CoM

IX-102 (from Instell's Ramjet-Pack): CoL quite behind CoM

Ravenspear Mk3: CoL quite behind CoM

So, I take from this "more or less everything works"

The following craft actually flies without main wing not that bad. It has similar problems to the version with a wing, but not as severe. Still, I have no idea why it's spazzing out. Both crafts tend to go into a "pitch-up/down-loop", unrecoverable. With the no-wing-version, it only happens when I change the pitch too fast. With the wing-version, it happens as soon as I look to forcefully at W/S (pitch).

The off-center-thrust isn't the problem, I think. I just hyperedited the craft into orbit, and while it starts pitching down a little bit under thrust, it's really nothing severe and can be corrected by the cockpit's SAS.

What the heck am I doing wrong?

Earlier version without canards, doesn't change much, though. Added them for better take-of.

Craft-file needs:

- Mk4 Parts (Air intakes)

- Scramjet parts (Leech Scramjet)

Download from Mega.co.nz

[TheXRuler]

I'd say you need FAR more wing area, like 3 to 4 times as much. Think bout it this way, in FAR and real life (I gather KSP now tries to model one of these at least) the maximum realistic wingload is around 0.5 tons per square meter. Now I don't know how much your craft weighs but I think you will simply have to add more wing are over all. Also, I assume you tried turning SAS off when it starts oscillating (stock SAS can be a bit crazy in the atmosphere)

[Alshain]

Not enough lift. Plain and simple. Try the FAT-455 wings, that piece you are using was designed as a tail fin. While it can be used as a wing, it's not big enough for a plane that size.

Also, you effectively have Canards and Horizontal Stabilizers there with no actual wings. You need Wings at the center of mass or your roll is going to be very difficult.

Edited May 12, 2015 by Alshain

[EtherDragon]

The issue you are facing is due to drag acting on the body at different angles compared to the center of lift for the wings and you are entering stall conditions at high angle of attacks where the wings no longer provide lift, but only produce drag.

Given equal surface areas, the wing furthest away from the center of mass will have the most torque. Your planes body also has drag and will apply torgue trying to flip it out, much like a rocket would if it didn't have tail-fins.

End result - your forward canard, and rear-heavy rocket, gives the front end a lot of torque. This is manageable until you get too high an angle of attack where the nose-heavy drag/torque overwhelms your controls.

[n0xiety]

You have no wings those are all controll surfaces. Yes they can act as wings but do you ever considered why real life planes doesn't have their whole wing movable. The moment you turn that thing it changes the lift so dramatically you loose your controll its that simple. Besides ksp controll surfaces are really powerfull now due to the new drag model. You need %90 wing %10 controll surface. Also lock the roll pitch and yaw from unnecesary controll surfaces. Like your tail for that plane should only work for yaw. And the controll surfaces you are using as wings should only be for pitch. So you actually don't have any roll movement atm. Roll can be done with wingtip controll surfaces.