When is the bank limit function available in the aircraft?

The bank limit function is designed to enhance safety and control by restricting the maximum bank angle that the aircraft can attain under specific conditions. This feature is typically activated in the HDG (Heading) or track modes, particularly when the aircraft is operating above a certain altitude threshold, such as Flight Level 250 (FL250).

When the aircraft is above FL250, the bank limit function helps to prevent overstressing the aircraft during turns and enhances overall flight safety by ensuring the aircraft maintains a controlled flight path. This is crucial when flying at high altitudes where the effects of aerodynamic forces can be more pronounced.

In contrast, climb mode, approach phases, or cruise at any altitude do not provide the same level of operational restrictions and controls as found in the HDG/track modes above FL250, making those scenarios less relevant for the activation of the bank limit function.