Unfortunately I am not aware of design software or a spreadsheet for simulating the performance impacts wing aspect ratio changes. Several model designers have generated code for their own use but no one appears to have productized their work. You may find the following white paper helpful in learning about the design tradeoffs involved in aspect ratio selection: Performance Analysis of a Family of R/C Thermal Sailplanes by Blaine Beron-Rawdon ([EMAIL PROTECTED]) http://www.rc-soar.com/tech/perfanal.htm There is a link on the above web page for downloading an Excel file displaying charts of glider performance parameters (the Excel file is only of results and does not include all of the code needed to generate the performance charts). Blaine Rawdon sells some excellent design software (Plane Geometry) but unfortunately this software does not address performance issues (and the influence of aspect ratio changes specifically). You may find some additional helpful information on the Charles River R/C web site http://www.charlesriverrc.org/articles_modeldesign.htm including Aspect Ratio Optimization (an answer to the question "is there an optimum AR" by Gavin Botha) Aspect Ratio vs. Drag (a quick writeup on the interaction of aspect ratio and model size) by Jeff Reid _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
