What does an amber USE MAN PITCH TRIM on the PFD indicate?

An amber USE MAN PITCH TRIM indication on the Primary Flight Display (PFD) alerts the pilots that the airplane is in pitch direct law. This condition typically occurs when the normal aircraft flight control laws are not available due to a failure or fault in the flight control systems. In pitch direct law, the flight control surfaces, such as the elevator, directly connect to the pilot's inputs, meaning that the aircraft does not utilize the normal flight envelope protections. This requires the pilots to manually manage pitch trim to maintain controlled flight.

When this indication appears, it signifies that pilots must be more vigilant in managing the aircraft's pitch since automatic protections may not be in effect. Understanding this feature is critical for ensuring the safety and proper handling of the aircraft under these operating conditions.