The FMS can automatically guide the aircraft along the flight plan route when which condition is met?

• A. The FMS is in degraded navigation mode
• B. The autopilot is coupled to the FMS flight plan
• C. The FMS calculates ETE only
• D. The aircraft is in manual mode

Answer: (B)

Automatic guidance along the flight plan happens when the autopilot is coupled to the FMS flight plan. With this connection, the FMS can hand off the route and constraints to the autopilot, allowing LNAV/VNAV guidance to steer the aircraft along every leg of the plan automatically. Without this coupling, the FMS may compute the route, but the autopilot won’t follow it automatically, so the pilot would have to intervene or enter guidance manually. Options involving degraded navigation, calculating only the estimated time en route, or operating in manual mode don’t provide the continuous automatic steering along the flight plan.