Fig. 6. The rate of change of vertical force coefficient (C_v) with angle of incidence ('), dC_v/d' for `early' and `steady' conditions from '=-20 to +20° for model hawkmoth wings with a range of aspect ratios (AR). Bars show 95 % confidence intervals (N=10). Differences both between high and low aspect ratios for either condition and between `early' and `steady' conditions for each aspect ratio are significant (P<0.01). The slopes of the regressions of dC_v/d' against AR for `early' and `steady' conditions are not significantly different and average 0.130.