About plane design

[Scrooge]

Target: design a highly maneuverable plane with conventional layout (2 vertical and 2 horizontal tails with 2 main wings)

FAR: Yes

CoM & CoL: the CoM is only a bit forward than CoL, the CoL is within the sphere of CoM

Problem: when flying, control the plane to rise its head will cause of trembling (up and down) head.

PS: I've already turned off the AoA and pitch SAS given by FAR, but the stock SAS is on.

Guess: The torque given by main wings is larger than that given by control-surface when the speed dropping down (which is cause by stalling)

Anyone has idea about this? Did someone once encountered this problem?

Thanks.

Edited December 10, 2019 by Scrooge

[Incarnation of Chaos]

Canards for extra pitch control are generally helpful if you're going for a inherently unstable design like this, but make sure to set the control limits so SAS doesn't freak out and cause noodling.

[Scrooge]

Just now, Incarnation of Chaos said:

Canards for extra pitch control are generally helpful if you're going for a inherently unstable design like this, but make sure to set the control limits so SAS doesn't freak out and cause noodling.

Canards have positive feedback when AoA is larger so I think it's a good idea.

But I am still curious about how this kind of phenomenon occurs, well, maybe it's not because of lift of main wings but the reverse torque given by SAS?

[James Kerman]

Welcome to the forum @Scrooge.

I've moved your topic to gameplay questions as it is a question about gameplay. 

[Scrooge]

Just now, James Kerman said:

Welcome to the forum @Scrooge.

I've moved your topic to gameplay questions as it is a question about gameplay. 

Thank you very much!

[Scrooge]

 

got an answer perfectly solve my puzzle.

To be honest, I've tried moving CoM backward until the aircraft was nearly static-unstable, but the improvement is limited.

I will try reduce angles of every control surfaces, and see how it goes.

Edited December 10, 2019 by Scrooge

[Fierce Wolf]

Press CAPS LOCK to turn it on. Your input will be smoother on the control surfaces.

[UncleManuel]

On 12/10/2019 at 9:04 AM, Scrooge said:

Target: design a highly maneuverable plane with conventional layout (2 vertical and 2 horizontal tails with 2 main wings)
 

Check the assignment (right click) of each control surface. By default all axis are turned on. I found the planes hard to control once they are in a stall spin, with the CoM centered or slight in front. The SAS has no chance of regaining control nor manual control (keyboard or XBOX-Controller for Windows)...

That said please note that KSP ist not a very accurate simulation of aerodynamics...

[Scrooge]

2 hours ago, UncleManuel said:

Check the assignment (right click) of each control surface. By default all axis are turned on. I found the planes hard to control once they are in a stall spin, with the CoM centered or slight in front. The SAS has no chance of regaining control nor manual control (keyboard or XBOX-Controller for Windows)...

That said please note that KSP ist not a very accurate simulation of aerodynamics...

Yeah, you are right, but I found it easy when you add exceeded control torque to fully cancel the fixed torque, then your plane can go any AoA you want...

I add TV engine (Panther), 2 reaction wheel, 40 degree control surfaces...and now, the plane can go stall and do Frolov's Chakra at a speed below 100m/s

High TWR make it quick to recover speed, I think I seize some inspiration, but I haven't figure the system out...

Edited December 14, 2019 by Scrooge