A noob asking a few questions.

[Bitrefresh]

Ive just recently acquired Kerbal space program. and i've recently been screwing about in the sandbox mode.

i know the games aerodynamics model has been over hauled. i've had the game since .90 but i never really touched it till now. a question i have

is why planes that have no canards at the front preform like crap but planes that do have them turn on a dime! it confuses me so much :s

[NathanKell]

Welcome aboard!

There are two things that control maneuverability:

1. Torque.

2. Stability.

Torque is the product of the control force times the lever arm--the larger the control surface the more force, and the farther away from the center of mass the longer the lever arm and the more that force gets magnified.

Stability is determined by how far the center of pressure is from the center of mass. If it's behind the center of mass (ye olde KSP axiom of "CoL behind CoM") the craft is statically stable (will follow the prograde marker when you take your hands off the controls), and if it's not, the craft is statically unstable (will tend to deviate ever further from prograde). If they're right on top of each other, you have neutral stability (the plane will move neither towards nor away from prograde). The further away the CoP is from the CoM, the stronger that stabilizes (or unstabilizing) force is.

Most KSP aircraft have their center of mass towards the rear, because that's where the heavy engines are. That means when you add canards at the front, they're both (a) larger than the control surfaces you usually add at the rear and ( much, much farther from the CoM than the ones at the rear. So they provide a lot of torque.

Next, because they're in front of the center of mass, they move the center of pressure forward compared to the center of mass, thus lowering stability and making the plane even more maneuverable.