Aerodynamic investigations in tandem twin aircraft are confined mainly to the effects of propeller slipstream variations on longitudinal control, trim, and stability. Slip stream velocities measured at the horizontal tail increase by a factor of three during a transition from a glide to a full throttle climb at 75 mph. Out-of-trim stick forces must be minimized by judicious placement of the elevator trim tab and careful design of the horizontal tail geometry.
Rear engine operation is superior to front engine operation in stability, control, and performance, offering 100% more longitudinal stability in climb and 24% more rate of climb at sea level.
