The swept-back wing has been used in almost all aircraft wings. This is necessary to reduce the pressure drag from the wings so that there is an increase in aerodynamic performance. The aerodynamic performance is the ratio between the total drag coefficient and the lift coefficient. This research attempts to explain the swept-back wing phenomenon in unmanned aerial vehicles (UAV) on Eppler 562 airfoil. The numerical simulation uses the k-ε turbulent model at Reynolds number (Re) = 2.34 x 104. Variation of backward swept angle Λ = 0°, 15°, and 30°. The separation growth Λ = 0° occurred more on the wing root, while Λ = 15° and Λ = 30° occurred more on the wingtip. At Λ = 15°, as the angle of attack increases, the area of the separation increases, and the area of the transition towards the separation decreases. The reattach area also has an increase in the area of the trailing edge. At Λ = 30°, with an increase in the angle of attack, there is a shift from the wingtip area to the mid-span. The area of separation and transition to separation has increased significantly. The re-attach area at α = 8o has not been seen, so at α = 12o it has been seen significantly. The vorticity on the x-axis shows Λ = 15°, and Λ = 30° has a wider area while on the z-axis, Λ = 15°, and Λ = 30° have stronger vortex strength. However, in the mid-span, Λ = 0° has a stronger result.