[B9] [Pwings] SSTO Help.

[Blue--Tempest]

First things first, I'm new to the forums, so sorry if I got anything wrong. I have had KSP for a while now and have bad prety bad luck with SSTOs. I feel like this one has a chance, and it flies amazingly, but there's one problem. When I run out of intakeair, and need to switch the SABRE over to Rocket Mode, the spacecraft starts doing death flips:huh:. The COM is towards the back, but way in front of the COL. Although I don't trust COL measures with Pwings. It seems suspicious... I do not have FAR installed, by the way, unfortunately. My friend doesn't want it and we try to keep the same mods. Ill post the .craft if you think you need it, but here's some screenshots.

http://prntscr.com/1q2rp7

http://prntscr.com/1q2s5c

Thanks in advance, and apologies for my stupidity.

Edited September 8, 2013 by Blue--Tempest

[boomerdog2000]

I can't tell from the picture, are you using two sabres or just one?

If you're using 2 it could be that one engine loses air and flames out before the second one possibly causing your death spin.

If you're using 1 engine it could be that once the engine loses air and flames out the angle of attack is too high for it so it flips.

Are you switching to rocket mode before you run out of intake air?

[Tex_NL]

In case you're using two SABRE's there is another possible cause: you're switching to rocket mode on just one engine and stay in jet mode on the other.

(It might seem far fetched but this has happened to me several times with disastrous results. Action groups are not always mirrored correctly when repositioning wings/engines.)

[Blue--Tempest]

I am using 1 SABRE-M. I switch to rocket before I run out of intake air. The angle of attack issue occurred to me, but it doesn't flip out when running on jets. Could it be because the rocket is just that much more powerful? I seem to get about the same amount of thrust. Sorry for the confusion... Its still puzzling me. I managed to get a tiny little SSTO into orbit, but I plan on adapting this design further once I know its capable of orbit. Thanks guys.

[Traches]

Do you have to pitch up like mad to get that thing to fly? Your CoL is really far aft compared to your CG-- and as the atmosphere gets thinner your control surfaces have less authority. You mentioned P-wings lies about the COL, which if it flies well I believe you're right.

It could have to do with your intakes-- are you closing them when you switch to rocket mode? Could be that the drag from the ones in back is stabilizing you. Try leaving the furthest back pair open.

[Blue--Tempest]

Yeah, it flies pretty well. But, like some of my other designs.. It wont take off until it "falls off" the runway, or according to my friend who was experimenting with it, retract the gear. I'm guessing that's just poor angle of attack though. Whats up with the Pwings is when I hover over where I want them to be placed, it shows what I believe to be the correct CoL. Then when I actually place them, it shifts, normally backwards. Here is a pic with me just hovering. Ill try the intake suggestion in a bit, and get back to you on it.

[Blue--Tempest]

Wow, forgot the picture. Here http://prntscr.com/1qd0o8