Ambitions to reduce the environmental impact of air traffic calls for novel solutions to improve the energy efficiency of large transport aircraft, independent of the propulsion type. A major contributor to aerodynamic drag is induced drag that can directly be approached by the wing aspect ratio as already pointed out by Ludwig Prandtl when formulating the lifting line theory. While glider aircraft achieve glide ratios up to 70 by highly stretched wings, current commercial transport jet aircraft operate at glide ratios up to 20. The DLR-F25 configuration was selected within the Clean Aviation project UP-Wing to address the challenges of distributing and installing multifunctional movable surfaces for aircraft flight control, gust and load alleviation and as high-lift system. It is a single-aisle medium-range aircraft competitive to an A321 size with an aspect ratio increased to 15.6. The current paper describes aerodynamic design investigations to install an alternative Advanced DroopNose Device (ADND) at the outboard part of the wing of the DLR-F25. In consequence of the high stretching of the wing, the cross sectional airfoil size on the outboard wing gets comparatively small. Standard high-lift systems as slat devices no longer fit with their systems into the limited space. The ADND is a variant of a droop-nose device featuring an additional bending panel at the interface to avoid the curvature discontinuity usually imposed. The present contribution will analyze in detail how such a device compares aerodynamically to the standard slat device. It will address the spanwise occupation for providing sufficient high-lift capability and inspect the aspects of the spanwise transition from a slat to the ADND device. The work will be based on steady Reynolds-Averaged Navier-Stokes flow simulations of the landing wing/body configuration (Figure 1), including engine effects in idle operation and considering different CFD methodologies for the design and analysis phases of the high-lift system.