Abstract: According to the characteristics of the wing in ground effect craft (WIG), this article defines the mission profiles of three kinds of WIG, and analyzes their correlation performance similarities and differences with common aircraft and the adaptability of the weight estimation methods. By searching and sorting out the data of existing WIG, the statistic relationship of takeoff weight and empty weight as well as other parameters are studied. By comparing with the fuel-fraction-method for estimating common aircraft weight, the fuel fraction of every stage of a WIG mission and the parameters selected in the correlation computation process are modified. Through data analysis and linear regression value calculation, the weight estimation methods and recommended experience factors which can be applied to every type of WIG are determined. The checking calculation result demonstrates that the estimated weights of WIG Class A and Class B and the actual products tally basically. For WIG Class C，due to the lack of adequate statistical data, it is difficult to check. However，the actual engineering design application results and the initial weight estimate results obtained with the analog method are basically the same, which suggests that the findings can satisfy the mission requirement for weight estimation during the system design stage.

Key words: wing in ground effect craft, takeoff weight, empty weight, estimation, mission profile, fuel consumption, fuel fraction