1. The repeatability of the force and moment data from the Pathfinder II model was analyzed within each test, and over the longterm (7 years), between the two tests. Repeat runs were not conducted for every configuration or for all Mach numbers, but were scattered throughout each test. The analysis for the available repeat runs was conducted using the methodology as described in reference 8. The analysis consists of statistical determination of the mean value of the selected coefficients from repeated runs, a curve fit of the data using a 2ndorder polynomial, and a determination of the residual of the individual data points from the curve fit data. Confidence intervals are determined and are defined as the bounds about an estimated mean that encompasses the true mean value with a probability of 95 % confidence.
2. Figures 15 through 18 show variations in model geometry for 3 configurations consisting of fuselage/wing, single horizontal and vertical tail, and twin vertical tails. The conditions for the data plots presented are Mach 0.6 at dynamic pressures of 589 and 1415 psf and Mach 0.9 at dynamic pressures of 797 and 1560 psf. The corrected data for each configuration is taken from the means of 2 repeat runs, in both angle of attack and twist. Thus a single symbol is used to represent mean data from 2 runs for each configuration at = 0.935. The results from 12 run pairs (24 total runs) presented in the 4 plots indicate that variations in model geometry due to aerodynamic loading are relatively independent of configuration. The variation in the change in model geometry for the 3 configurations are only slightly more that the repeatability of back-toback measurements, except possibly for the higher angles of attack. The maximum flow induced twist of 0.9° occurs at the outboard station at the largest dynamic pressure of 1560 psf. The wing is essentially undeformed at approximately 2°. The deformation data at alpha = -2° and 10° of figures 15 - 18 for the 3 configurations are plotted in figure 19 versus dynamic pressure. Linear least square fits to the data at the 2 angles of attack are superimposed to illustrate the nearly linear behavior with dynamic pressure. Again, very little variation due to configuration is noted.
3. The repeatability of the repeat runs at = 0.935 presented in figure 14 is shown in figure 20. The range of the repeat data is less than 0.06° with about 70% of the variation having a range of only 0.02°. Repeatability data for the 12 run pairs used for figures 15 - 18 for all 3 configurations are shown in figure 21. The mean of the differences between repeat runs is generally less than 0.02°. The maximum difference was generally less than 0.05° with a slight decrease in repeatability for the higher dynamic pressures. The maximum difference between repeat runs was less than 0.05° for 9 of the 12 run-pairs.
4. In addition, longitudinal data demonstrating the effects of fixing the boundary layer transition location for low Reynolds number conditions was analyzed. This data will show the effect of transition on the separate components of the configuration in detail and compare measured drag data to a theoretical estimate based on the variation of skin friction with Reynolds number. Fuselage / Wing Configuration (FW) Lateral-Directional Rn Effects