ESDU 95021 presents an empirical method that depends on determining the increment for an aerofoil representative of the wing and applying factors to allow for three-dimensional and part-span effects. ESDU 94031 is used to predict the increment for the aerofoil@ depending on the extended deployed chord. That increment is factored by the ratio of the wing to aerofoil lift curve slopes obtained respectively from ESDU 70011 and ESDU Aero W.01.01.05@ thereby accounting for aspect ratio@ taper and sweep effects. Finally@ part-span factors are applied that depend on the spanwise centre of pressure of the loading due to incidence obtained from ESDU 83040. For double-slotted flaps@ the range of parameters for which the method was validated are tabulated and include aspect ratios of 3.7 to 10@ taper ratios from 0.3 to 0.5@ leading-edge sweep up to 48 degrees@ Mach numbers up to 0.2@ first element deflections of 12 to 48 degrees and second element of 13 to 30 degrees. For triple-slotted flaps@ no experimental data were found but it is anticipated the method will apply equally well. Sketches show the correlation between experimental results drawn from the literature and predicted results; for all results@ 89 per cent were correlated within 15 per cent. A worked example illustrates the use of the method.