What is referred to as the dis-symmetry of lift in helicopter flight?

The term 'dis-symmetry of lift' in helicopter flight primarily refers to the difference in lift generated between the advancing and retreating rotor blades. As the rotor blades spin, the blade that is moving forward (advancing blade) travels through the surrounding air at a higher speed, resulting in increased lift compared to the blade that is moving backward (retreating blade), which experiences lower airflow and generates less lift. This inherent difference is crucial for the helicopter's performance, particularly in forward flight, because it influences the helicopter's stability and control. Understanding this phenomenon is vital for pilots, as it affects how they manage the aircraft during various maneuvers, thereby impacting safety and efficiency.