Str^m-Tejsen and Chislett 



Pure Sway TesI 



y^ y ^^v y^ 



jr>«g — t~:s»r X 



Fig. 3 - Pure sway test executed in the 

 dynamic mode of planar-motion mech- 

 anism operation 



this type of test are shown in Fig. 4, the two developments of the "pure -yaw 

 test," i.e., the "yaw and drift angle test," and the "yaw and rudder angle test," 

 constitute a means of measuring crosscoupling terms in the equations of motion. 



As a means of experimentally measuring acceleration as well as angular 

 velocity, drift angle, and rudder angle derivatives, the planar-motion mechanism 

 system constitutes an almost ideal method of obtaining all the linear terms 

 needed for course stability studies (6,7). The same basic approach can be ex- 

 tended to measurement of nonlinear and crosscoupling terms in angular velocity, 



Yaw and Drift Angle Test 



YSwv and Rudder Angle >st 



Fig. 4 - Various examples of yaw tests 

 executed in the dynamic mode of planar- 

 motion mechanism operation 



324 



