Which one of the following is not an input utilized by the aircraft navigation system?

A)
Sonar
B)
Radio aids
C)
Dead reckoning data
D)
Celestial measurements

Correct Answer :   Sonar


Explanation : The navigation system utilizes three types of sensor information: position data from radio aids, radar and satellites; Dead reckoning data from inertial sensors; Line of sight direction to stars or celestial measurements.