What occurs when an aircraft encounters wind shear during VNAV?

When an aircraft encounters wind shear during Vertical Navigation (VNAV), the Flight Management System (FMS) may need to recalibrate descent rates to account for the sudden changes in wind speed and direction. Wind shear can create unexpected variations in lift and drag, which can affect the aircraft's performance. As a result, the FMS adjusts the descent rates to stabilize the aircraft's flight path but may still require the pilot's input to ensure safe operation.

During an event of wind shear, the automation systems in the aircraft work to maintain safety and control, but they may not always fully compensate for the rapid fluctuations. Therefore, the pilot's awareness and intervention become crucial. The FMS alone may not handle all scenarios effectively, necessitating the need for the pilot to assess the situation and apply manual adjustments if required.

This makes it essential for pilots to be trained and aware of how to respond to wind shear situations, utilizing both the FMS and their manual flying skills. Understanding how the FMS recalibrates descent rates helps in comprehending the complex interactions between automation and pilot intervention during challenging situations such as wind shear.