What is static balance in regard to a rotor blade?

Static balance in regard to a rotor blade refers to the condition where the center of gravity is perfectly aligned with the center of lift when the rotor blade is at rest. This alignment ensures that there is no tendency for the rotor blade to rotate or tilt due to unequal forces acting on it. Achieving static balance is crucial for maintaining stability in flight, as an unbalanced rotor blade can lead to issues such as excessive vibrations and control problems during operation.

When a rotor blade is statically balanced, it will not drop or tilt when positioned horizontally, which is essential for ensuring smooth and controlled flight operations. This balance is foundational to rotorcraft performance because any imbalance can adversely affect flight characteristics and pilot control, especially during various phases of flight.

Other options either do not accurately describe static balance or refer to different aspects of rotor blade functionality. For example, a situation where the rotor blade is off-balance during flight describes a dynamic condition rather than one at rest. Similarly, the alignment of the main rotor with the tail rotor and setting rotor speed for maximum lift pertain to different mechanical aspects and operational objectives rather than static balance specifically.