Table 2 shows summary statistics of the finally updated posterior distributions. From the table, it is seen that the COV of testing variability in drag coefficient between drops is between 5 and 8% (i.e., COV of helicopter 1 is 0.062/0.778 = 7.9%), while the COV of manufacturing variability is about 12% (COVs of mean of the mean). Repeated tests significantly reduce the uncertainties in the estimated mean and STD of drag coefficient, for instance, the STD of the mean, which quantifies the uncertainty in the average of tests, is smaller than the mean of STD, which represents the uncertainty in a single test, by one third for all helicopters. Because the manufacturing variability is large, the helicopter performances may be substantially different; even though they are manufactured based on the same helicopter dimensions, their results are treated as different helicopters in the validation experiments.