Elevator effectiveness and elevator lift coefficient

Has the elevator lift coefficient parameter been implemented? I am not
noticing a difference in the pitch response of the default A320 for values of
this parameter ranging from 0.1 to 20. (Edit: I can see from the on ground
response that the elevator lift coefficient has an effect. I just can’t see
the effect in flight when trying to find the optimum way to tune pitch
response to an elevator control input.) Along that vein, how is the elevator
effectiveness parameter supposed to work? Reducing the value of the aileron
effectiveness parameter results in a very noticeable reduction in the
airplane’s roll response; increasing the value increases the roll response.
However, the same does not see to hold true for the elevator effectiveness
parameter and the airplane’s pitch response. In fact, it seems to be inverted.
Values between 0.1 and 1 seem to have no effect. With a value of 10, you
pretty much lose pitch response to elevator input. Testing this on the default
C152 seemed to show somewhat different results. Changes to the elevator
effectiveness appeared to change the effectiveness of the horizontal tail
rather than the elevator. Decreasing the effectiveness to 0.1, for example,
would send the airplane into a dive with neutral trim, potentially indicating
a large lift increase for the horizontal tail. Normal pitch control still
seemed available from the elevator.

Hello @donstim The maximum theoretical value for this lift slope coefficient
is so setting anything above shouldn’t make any difference. I’ve been
able to see the influence on both in flight testing with the A320 using the
Pitch aircraft debug view. From what I can see in my tests,
elevator_lift_coef tends to change amplitude of the lift and
elevator_effectiveness how fast variations happen. Regards, Sylvain

My evaluation was not really correct. In fact, they both influence the lift
curve in the same way. Our recommendation is to keep
elevator_effectiveness at 1.0 and solely use the
elevator_lift_coef. The later was just exposed to make it a bit more
explicit that you control a slope that was previously hardcoded to 5.0 rather
than a scalar applied on it.