What is the normal hydraulic reservoir quantity displayed on the Synoptic page?

The normal hydraulic reservoir quantity displayed on the Synoptic page is significant for ensuring that the hydraulic systems of the aircraft are functioning properly and have sufficient fluid necessary for operation. A range of 45% to 85% is indicative of a healthy hydraulic system that can effectively manage the demands placed on it during various phases of flight, such as takeoff, cruise, and landing.

This range assures pilots that there is enough hydraulic fluid to operate essential flight controls and systems, helping to prevent issues that could arise from low hydraulic fluid levels, such as loss of control surface effectiveness or system failures.

The other ranges provided do not align with the operational limits established for the aircraft's hydraulic systems and would not provide the same level of assurance regarding safe operation. Maintaining hydraulic fluid within the specified range is crucial for optimal performance and safety of the aircraft.