Analysis on Enhancement of Control Moments Using Control Surfaces and Multiple Propellers

Abstract

The lateral/directional attitudes of small airplanes are easily disturbed by crosswind in take-off or landing operations, because the flight velocities and moments of inertia are smaller than those of large airplanes. Although conventional airplanes mainly control their lateral/directional attitudes by using the control surfaces such as an aileron and a rudder, the moments generated by the control surfaces are not enough in low-flight-velocity conditions such as in take-off or landing operations. The present paper focuses on a control strategy using multiple tractor propellers for small airplanes to generate sufficient moments in the low-flight-velocity conditions. This method utilizes the thrusts of propellers and the effect of interaction between the propellers and the main wing in addition to control surfaces. The present paper confirmed this method approximately achieves to double the control moments compared with those just by the control surfaces and showed the relationship between the number of propellers and the control moments in this method.