What is the first action for a PITCH AUTHORITY warning?

The first action for a PITCH AUTHORITY warning is to quickly reduce airspeed to 280 KCAS or below and split the STAB TRIM handles. This is critical because the warning indicates a potential loss of control regarding the aircraft's pitch stability. By reducing airspeed, the pilot helps maintain control and avoids entering a situation where pitch authority could be significantly impaired.

Additionally, splitting the STAB TRIM handles effectively disconnects the automatic stabilization system, allowing the pilot to manually handle pitch adjustments, which can be essential during an emergency situation. This action prioritizes the pilot's control over the aircraft and helps prevent exacerbating any existing issues related to pitch authority.

The other options, while they may have their own relevance in certain situations, do not directly address the immediate requirement to regain pitch control when the warning is issued. Maintaining adequate airspeed and manual control is paramount for stabilizing the aircraft during this warning condition.