During descent, which mode is selected to begin the descent?

During descent, which mode is selected to begin the descent?

• A. OPEN DES
• B. OPEN DESC
• C. OPEN DESN
• D. OPEN DESA

Answer: (A)

Open Descent is the mode you use to start descending from cruise altitude. It tells the autopilot/automation to begin following the published descent path down to the next altitude constraint, while the flight director guides the aircraft along that profile. This mode is designed for initiating descent in a controlled, profile-driven way, letting the system manage the vertical path and speed constraints as you begin your downward leg. The other labels aren’t standard modes you’d select to start a descent, so they wouldn’t initiate the descent in the same way. Open Descent specifically signals the automation to engage the open descent profile, which is why it’s the correct choice here.

Open Descent is the mode you use to start descending from cruise altitude. It tells the autopilot/automation to begin following the published descent path down to the next altitude constraint, while the flight director guides the aircraft along that profile. This mode is designed for initiating descent in a controlled, profile-driven way, letting the system manage the vertical path and speed constraints as you begin your downward leg.

The other labels aren’t standard modes you’d select to start a descent, so they wouldn’t initiate the descent in the same way. Open Descent specifically signals the automation to engage the open descent profile, which is why it’s the correct choice here.