For runs with fixed hull pitch angle w, (W=0), the value of p could 
be controlled to within +0.005 degree. For dynamic pitch runs +0, the 
selection of a propeller revolution at a specified ~ necessitated a toler- 
ance of 0.1 degree to ~; however, the average value of ~ for which data 
are presented during the unsteady runs was generally within 0.02 degree of 
the target }. 
Considering all sources of error including deviations during a run 
and inaccuracies in setting conditions, the model scale forces and moments 
presented in this report are generally considered to be accurate to within 
(plus or minus) the following variations: 
g Fax M MMAX 
1b = «© (N) 1b (N) jin-1b (N-m)}jin-1lb (N-m) 
Steady ahead V=0,U=0 | 0.1 (0.4) | 0.2 (0.9)| 0.2 (0.02)| 0.4 (0.06) 
Dynamic pitch V=0,040| 0.2 (0.9) | 0.3 (1.3)| 0.4 (0.04)| 0.6 (0.07) 
Acceleration V>0,=0 ONSH Gl3))E ON aaa Glee) Om One (ORO) a Ole (0.09) 
The values are somewhat more accurate for the steady-ahead runs than 
for the time-dependent runs, because the experimental conditions could be 
controlled more precisely for the steady runs and the measured forces and 
moments were averaged over many more revolutions of the propeller. The 
time-average values per revolution (based on 90 samples per revelolution) 
are slightly more accurate than the maximum values (based on one sample 
per revolution) which took into account the variation with blade angular 
position. Further, the peak values may have been slightly influenced by 
the dynamic response of the flexures, as discussed in the section on cali- 
bration. 
EXPERIMENTAL RESULTS 
LOADING COMPONENTS 
The basic loading components are shown in Figure 1. For a right- 
hand propeller the sign convention follows the conventional right-hand 
rule with a right-hand Cartesian coordinate system. For a left-hand pro- 
peller all the loads are the same, but for this case the sign convention 
follows a left-hand rule with a left-hand Cartesian coordinate system. 
3} 
