Some of the FMS have a navigation mode called Dead Reckoning mode (DR), computing airspeed, heading, wind data ground speed and time. This mode is: - ATPL

Question id 57 - Aircraft General Knowledge - Instrumentation - ATPL - Airline Transport Pilot license

A navigation mode used to monitor the FMS position.

An operating mode used to intercept radials To or From a flight plan waypoint.

The normal navigation mode for FMS which do not use Inertial navigation Systems INS to compute the aircraft position.

A back up navigation mode to compute a FMS position when the other navigation sensors are no longer operating.