ESDU Aero F.01.01.08 has been superseded by ESDU 93019 but is retained because other documents still current in the Series make reference to it. It is restricted to full-span single-slotted flaps on an unswept wing but the factors in ESDU 74012 may be used to correct results obtained from it to apply to part-span flaps. The method of 93019 applies to a flap that may be part-span on a wing that may be swept. The correlation presented in ESDU 93019 is based on that developed for the two-dimensional case in ESDU 94030; for the methods for both the wing and the aerofoil more recent data were available than could be used for the method of ESDU Aero F.01.01.08. For those reasons ESDU 93019 should always be used to obtain the lift increment due to the deployment of a single-slotted flap. For multi-slotted flaps ESDU 95021 should be consulted.