Prior to using SPEED, V/S or PITCH mode to change altitude, what must first be done?

Prior to using SPEED, V/S or PITCH mode to change altitude, what must first be done?

• A. Activate the autopilot
• B. Selection of a new altitude with the ALT knob
• C. Set a new airspeed
• D. Engage the approach mode

Answer: (B)

Setting a target altitude with the ALT knob is the prerequisite for any vertical mode to change altitude. The ALT selector provides the reference point the flight control system uses to determine whether to climb or descend. Once a new altitude is selected, engaging a vertical mode—SPEED, V/S, or PITCH—tells the system how to progress toward that target. SPEED adjusts airspeed during the transition, V/S commands a climb or descent rate, and PITCH guides the airplane along a flight path to reach the set altitude. Without a selected altitude, these modes have no destination and won’t initiate an altitude change. The autopilot can manage the effort automatically once the altitude is set, but the essential first step is choosing the new altitude. Setting a new airspeed is not required to start altitude changes, and engaging approach mode isn’t necessary for climbing or descending to a new altitude.

Setting a target altitude with the ALT knob is the prerequisite for any vertical mode to change altitude. The ALT selector provides the reference point the flight control system uses to determine whether to climb or descend. Once a new altitude is selected, engaging a vertical mode—SPEED, V/S, or PITCH—tells the system how to progress toward that target. SPEED adjusts airspeed during the transition, V/S commands a climb or descent rate, and PITCH guides the airplane along a flight path to reach the set altitude. Without a selected altitude, these modes have no destination and won’t initiate an altitude change. The autopilot can manage the effort automatically once the altitude is set, but the essential first step is choosing the new altitude. Setting a new airspeed is not required to start altitude changes, and engaging approach mode isn’t necessary for climbing or descending to a new altitude.