Charts for estimating tail-rotor contribution to helicopter directional stability and control in low-speed flight /

The charts indicate, and flight tests confirm, that the region of vortex roughness which is similar for the main rotor is also encountered by the tail rotor, and that prolonged operation at the corresponding flight conditions would be difficult.The use of the charts and equations for tail-rotor design studies is illustrated. Comparisons between theoretical and experimental results are presented.Theoretically derived charts and equations are presented by which tail-rotor design studies of directional trim and control response at low forward speed can be conveniently made. The charts can also be used to obtain the main-rotor stability derivatives of thrust with respect to collective pitch and angle of attack at low forward speeds.NACA TN No. 3156.Includes bibliographical references.The charts indicate, and flight tests confirm, that the region of vortex roughness which is similar for the main rotor is also encountered by the tail rotor, and that prolonged operation at the corresponding flight conditions would be difficult.The use of the charts and equations for tail-rotor design studies is illustrated. Comparisons between theoretical and experimental results are presented.Theoretically derived charts and equations are presented by which tail-rotor design studies of directional trim and control response at low forward speed can be conveniently made. The charts can also be used to obtain the main-rotor stability derivatives of thrust with respect to collective pitch and angle of attack at low forward speeds.Mode of access: Internet