| 73 / | HD | MEASURING AND TESTING | 
| 488 | DF | SPEED, VELOCITY, OR ACCELERATION {29} | 
| 504.02 | DF | .~ Angular rate using gyroscopic or Coriolis effect {4} | 
| 504.08 | ![]()  | .~.~ Rotary gyroscope {2} | 
| 504.09 | DF | .~.~.~> Gimbal support | 
| 504.11 | DF | .~.~.~> Flexible rotor or flexibly mounted rotor |