A change in altitude is primarily controlled by which axis?

The correct choice pertains to the lateral axis, which is fundamental in understanding how an aircraft changes altitude. The lateral axis runs from wingtip to wingtip and is crucial for controlling pitch, which directly influences altitude. When an aircraft pitches up or down, it alters its angle of attack, which impacts lift and consequently affects altitude either by climbing or descending.

The longitudinal axis, on the other hand, is oriented from the nose to the tail of the aircraft and is primarily involved in control of roll. The vertical axis runs vertically through the center of the aircraft and is associated with yaw movement, which affects the aircraft’s direction rather than altitude. There is also no conventional reference to a transverse axis in standard aviation terminology, as the commonly used axes are the longitudinal, lateral, and vertical. Thus, understanding the lateral axis is key to grasping how altitude is managed during flight.