What major factor affects sling load stability during flight?

Wind velocity and direction play a crucial role in influencing sling load stability during flight. When a helicopter is in motion, changes in wind can create forces that affect how the load hangs underneath the helicopter. If the wind is strong or comes from an unexpected direction, it can cause the load to sway or shift, impacting the overall stability of the flight. The helicopter might also have to adjust its flight path or speed to compensate for these wind effects, ensuring the load remains balanced.

While the weight of the load is significant in terms of the helicopter's capability to lift it, and the type of helicopter can determine how it responds to loads, these factors themselves don't directly address the dynamic stability the load experiences during flight. Similarly, altitude can affect performance but is less impactful on the immediate handling characteristics of a sling load compared to the effects of wind conditions. Therefore, understanding and monitoring wind variations is essential for maintaining stability and safety during sling load operations.