Results of a study of the accuracy attainable from various approaches to low aspect ratio wing deformational analyses are described. Seven model multi-web wings, representing a restricted range of sweep angles, aspect ratios and other geometric factors, were tested for deflection influence coefficients. Methods of matrix structural analysis and other techniques, involving numerous idealisations, were then applied in the prediction of the test data. This paper presents the experimental data. Subsequent papers will describe the analytical methods, the level of test-theory correspondence, and the merits and shortcomings of the theories studied.