An important issue regarding landing performance is the reference speed which determines the approved fields lengths in which a landing can take place. A critical scenario is the accumulation of ice during the holding phase followed by descent, approach and landing. The effect of icing in the landing configuration, with the high-lift devices deployed, is relevant and should be anticipated during the early design phases by simulation. Due to the complex behaviour of the flowfield, 3D CFD methods has been used by several manufacturers but that leads to a high computational cost which might be too intensive for the preliminary design phase. The present work presents a Quasi-3D lower cost procedure combining 2D viscous airfoil data with 3D inviscid wing data to allow for the calculation of the aerodynamic characteristics of an iced wing providing an accurate assessment of the icing effects in ΔCL (comparing clean and iced configurations), within a 5% variation confirmed by wind tunnel testing.