Purpose – This thesis investigates the Excel-based aircraft sizing tool RASCE to redesign a passenger aircraft. It is investigated if OpenVSP-Connect can be a general bridge from Excel-based aircraft design tools to NASA's OpenVSP for visualization. This is shown with RASCE and with PreSTo-Classic, which is another Excel-based aircraft sizing tool. Moreover, it is checked, if it is possible to optimize aircraft designs with simple sizing tools just with Excel's Solver. --- Methodology – The named existing tools are combined with appropriate programming. --- Findings – OpenVSP-Connect is able to bridge from Excel-based aircraft sizing tools to OpenVSP for visualization. The result is satisfactory and resembles real passenger aircraft. The optimization with Excel's Solver manages to deliver adequate results. The ability to save and load multiple solver specifications makes it possible to work with numerous optimization scenarios. When the Excel-based tools are opened with free spreadsheet software (Calc), optimization was impossible due to a lack of an advanced (non-linear) solver. --- Research limitations – Only one aircraft type (the Airbus A320) was redesigned for this thesis. OpenVSP-Connect was tested only on two aircraft sizing tools. Limited by the simple nature of the aircraft sizing tools, only a small set of aircraft design parameters was available for optimization. --- Practical implications – It was shown that visualization (with OpenVSP) and optimization (with Excel's Solver) can be introduced quite easily already into simple aircraft preliminary sizing tools. This enables these activities to be introduced into an aircraft design course with limited weekly hours. --- Originality – This seems to be the first scientific report to discuss aircraft visualization and optimization with very simple spreadsheet-based aircraft sizing tools.