Weight Estimation Method for Early Conceptual Design of Wing-in-ground-effect Vehicles

This work describes a semi-empirical weight estimation method for wing-in-ground-effect (WIG) vehicles. The method is based on existing regression equations used for conceptual aircraft design, with modifications that make them more applicable for WIG craft. Modifications of airframe weight methods were performed using data of three available and six reverse-engineered WIG craft of different kinds to capture various configurations and sizes. Weight components related to systems and equipment were also selected as a collection of regressions that can be used for such vehicles. Sensitivities of most critical airframe components regressions were checked using the Leave-One-Out Cross-Validation (LOOCV) method, and their uncertainty bounds were quantified. A comparison of the proposed and original methods demonstrated substantial improvement of absolute operating empty weight (OEW) error from 15.4% for the original method to 7.4% for the modified one. The root mean square error of OEW also improved from 20% to 8.9%, demonstrating that the new method is more reliable for WIG craft at the conceptual design stage. Finally, uncertainty bounds related to systems weight estimations were quantified.