Preliminary Wing Sizing G. Marien AE460 Lecturer

Topics Design Process Refresher Design Mission/OV-1 Diagram Preliminary Weight Estimate (spreadsheet) Preliminary Wing Sizing

Preliminary Design Process (Roskam) Statement of Work System Requirements Document Part I Preliminary Sizing Sensitivity Studies MGTOW or TOGW (WTO) Takeoff Thrust (TTO) Wing Planform Area (S) Aspect Ratio (AR or A) Empty Weight (WE) Fuel Weight (WF) Payload Weight (WPL) CLmax (clean, TO/L) Used for Refinement of Preliminary Sizing Part II Configuration Layout and Propulsion System Options Initial Layout of Wing and Fuselage Tail Sizing Weight and Balance Drag Polar Landing Gear Configuration Candidates Identified for Further Study Layout of Wing, Fuselage and Empennage Weight and Balance Drag Polars Flap Effects Stability and Control Performance Structural Layout Landing Gear Life Cycle Costs Refinement Sizing Iteration and Reconfiguration Other Design Activities Flight Loads Structural sizing Preliminary Configuration Design Complete

OV-1 : RCR 1.1.2 Present an OV-1 diagram with key requirements, design missions and design features of the aircraft that meet the requirements. Print on a single 11x17” sheet. You may use 2 sheets if needed to convey your message

Weight Estimate Spreadsheet Weight Estimate based on: Takeoff weight “guess” Design mission profile/payloads Estimated fuel fractions from similar aircraft Note: these weight values can feed back into the design mission segment values (temporary).

Wing Sizing Q: When designing aircraft, what are two key factors do engineers have to focus? A: Weight and Cost Smaller is better for weight and drag therefore – thrust But, still need to meet the requirements.

Sizing Calculated Guess Requirements come from: SRD (customer requirements) 14CFR23 14CFR25 MIL-C-005011 Takeoff Sizing - Example Takeoff Landing Cruise Climb Including OEI Time to Climb or Rate of Climb Maneuvering Use an input W/S (wing loading) to obtain a T/W (thrust to weight) Requires a lot of estimating

Wing Size Matching W/STO (takeoff wing loading) = XX psf T/WTO (takeoff thrust to weight) = XX psf