How is the loss of normal law displayed on the PFD?

The display of a loss of normal law on the Primary Flight Display (PFD) is crucial for pilots to understand the aircraft's flight envelope and its current operational limitations. In the scenario of losing normal law, a red 'X' is presented, indicating that normal flight control laws are no longer in effect, signifying a shift to alternate or direct law, which can alter the handling characteristics of the aircraft.

In this context, it’s important to recognize that the red 'X' serves as a clear and immediate visual cue to pilots of the significant change in the aircraft’s control laws, alerting them to adjust their flying techniques accordingly. The presence of this warning helps pilots quickly assess the situation and respond to any potential flight safety issues that may arise from operating under alternate or direct law.

Additional symbols, such as the green symbols, refer to different states and parameters, which do not indicate a loss of normal law, hence making them less relevant in this particular scenario. The amber 'x' might suggest a less severe condition, but it is not used to denote a complete loss of normal law on the PFD.