ESDU 93007 applies to single or twin fins on aircraft at angles of attack up to 5 degrees and angles of sideslip up to 4 degrees. It treats a wider range of body height/width ratios than ESDU 82010 which deals with the single body-mounted fin for geometries typical of transport aircraft where body height/width ratio is close to one. The fin sideforce is calculated by applying a semi-empirical interference factor to a basic lift-curve slope estimated from ESDU 70011 for the wing obtained when the fin is reflected about its root chord. The interference factor takes account of body@ wing and tailplane interference@ and three factors are provided depending on the relative positions of all lifting surfaces. For twin fins a further empirical factor is applied. Yawing and rolling moments follow once the point of action of the sideforce is known; the point empirically determined in ESDU 82010 based on an assumed elliptical loading along the fin quarter-chord line was found to be satisfactory here as well. Methods are also given for estimating the small contributions to the yawing and rolling moments from a body-mounted tailplane. Plots of predicted results against experimental data extracted from 24 sources in the literature (together with some unpublished results) show the sideforce@ yawing moment and rolling moment derivatives to be estimated within 0.08@ 0.04 and 0.02 respectively. The ranges of geometry covered by the test data are tabulated@ and two fully worked examples illustrate the use of the methods.