ORIGINAL: tripower222
Why don't airplanes with high lift wings (like flat bottom trainers) have lifting/airfoil horizontal stabs.
No need for them. Much easier to produce a flat plan-form than airfoiled, especially with ARFs. Old Free-Flight models did so.
I would think if the lift and tail moment where calculated correctly once the elevator is trimmed, the plane would fly level at any airspeed, above stall of course. I would think it would make a more stable plane which is idea behind a trianer.
It does to a degree, However with any change in airspeed the lift of a lifting surface is increased by 1/2 of the square of the airspeed (
airspeed being the actual flow of air molecules over the surface, known as Indicated Airspeed, NOT True Airspeed, Groundspeed, and/or Calibrated Airspeed) However the surfaces being different the change in lift-force produced with a change in airspeed is NOT directionally proportional.
The climb/descent of an airplane with a change in airspeed is simply an increase/decrease in the production of "lift" by the main wing in traditional convergent airflow. A lifting stab will not totally change that. It can help some but not adequately to rule out any change with aircraft velocity changes.
There is much more but not needed here.