ESDU AERO C.04.01.06:1989

ESDU Aero C.04.01.06 gives equations for the rates of change of hinge moment coefficient with incidence and with control deflection which include a spanwise integration of their respective values in two-dimensional flow. Those two-dimensional values may be obtained respectively from ESDU Aero C.04.01.01 and C.04.01.02 and if necessary may be corrected for the effect of nose or internal balance using ESDU Aero C.04.01.03 and C.04.01.04 respectively. Both equations involve parameters for which values have been calculated using lifting-line theory applied to elliptical loading for unswept wings together with a correction factor for non-elliptical loadings and all the factors are presented graphically. The equations also involve respectively the sectional lift-curve slope and the sectional value of the slope of the lift coefficient curve with control deflection for which values may be obtained respectively from ESDU Aero W.01.01.05 and C.01.01.03. The equation for the rate of change of hinge moment with control deflection includes in addition the integration of the sectional value for the rate of change of hinge moment with incidence. For quantities not involved in the integrations, mean values are taken appropriate to the a mean section geometry. The method is illustrated with a fully-worked practical example.