Well in simplest terms, you’d probably want to start with getting the Vector between your AI position and the target position.

e.g. (not sure if this compiles – doing it from memory – but you’ll get the idea)

//assuming you have a TargetThing object and an AIThing object, both with Position
//(vector3) properties defining their position in the world.

Vector3 targetPosition = TargetThing.Position;
Vector3 aiPosition = AIThing.Position;

//the difference between these to vectors gives you an offset vector
//from one to the other

Vector3 offsetToTarget = targetPosition – aiPosition;
float distanceToTarget = offsetToTarget.Length();

//you probably don’t want your AI to warp jump straight to that position
//so we normalize the offset vector (turns it into a vector heading the same direction,
//but with a length of exactly 1.

Vector3 moveDirectionVector = Vector3.Zero;
if (distanceToTarget > 0) //Normalize would get odd result if the positions were the same.
{
moveDirectionVector = offsetToTarget
moveDirectionVector.Normalize();
}

//now to actually move your AIThing in that direction
//you’ll want something kind of like this.
//Note: your games Update method would likely have a gameTime parameter.
//AIThing.MaxSpeedPerSecond would be a float value defining how far something would move in a Second.
//gameTime.ElapsedGameTime.TotalSeconds is how many seconds
// (likely fraction of a second) have passed since the previous Update.
//We use it to even out the perceived movement regardless of the
//game’s Framerate which fluctuates.

Vector3 velocity = moveDirectionVector * AIThing.MaxSpeedPerSecond * gameTime.ElapsedGameTime.TotalSeconds;

//add the velocity to your AI’s position to move it.

AIThing.Position = AIThing.Position + velocity;

Hope that helps?

As promised I checked out your game. I just ran it on the Xbox360.
I tried several game modes and planes. Did not experience a crash or slow down.

Hope this helps.

Bino