chris
Well-Known Member
Hey guys,
I aksed this Q on the flightinfo forum, and now I will transfer it here. I hope some people can add to the discussion.
I realize that the elevators become more responsive as the CG moves aft. (i.e. lighter force required to generate a response).
However... if the rudder is more effective with a more forward CG (i.e. with multi engine a/c, Vmc is lower with a forward CG because the arm between CG and the rudder is longer), then why doesn't this principle apply to the elevators?
It seems to me that all movements occur through the CG, as that is where the weight is centered. With a forward CG, the arm between the elevators and the point from which the aircraft pitches is longer, so more moment is produced here. But, this analogy is obviously wrong.
Am I omitting the Centre of Pressure, or should this not be a factor for pitch authority?
Thanks in advance.
I aksed this Q on the flightinfo forum, and now I will transfer it here. I hope some people can add to the discussion.
I realize that the elevators become more responsive as the CG moves aft. (i.e. lighter force required to generate a response).
However... if the rudder is more effective with a more forward CG (i.e. with multi engine a/c, Vmc is lower with a forward CG because the arm between CG and the rudder is longer), then why doesn't this principle apply to the elevators?
It seems to me that all movements occur through the CG, as that is where the weight is centered. With a forward CG, the arm between the elevators and the point from which the aircraft pitches is longer, so more moment is produced here. But, this analogy is obviously wrong.
Am I omitting the Centre of Pressure, or should this not be a factor for pitch authority?
Thanks in advance.