Which of the following is NOT a factor that affects a sling load's in-flight stability?

In-flight stability of a sling load is influenced by several key factors, and understanding which elements contribute to that stability is crucial for effective operations. The correct answer focuses on weight distribution as not being a direct factor affecting in-flight stability during a sling load operation.

Proper weight ensures that the load is within the helicopter's lift capabilities, while the proper drag surface helps maintain control and reduces unwanted aerodynamic effects. Proper airspeed is vital because it influences the helicopter's lift and the ability to control the load during flight. However, the actual distribution of weight within the load does not inherently affect the stability of the sling load once it is airborne, though an unevenly distributed load could lead to handling or load separation issues during flight. Therefore, while weight distribution is important for other reasons such as preventing equipment damage or ensuring safety during loading and unloading, it does not directly control stability in the air like the other factors do. This distinction highlights the complexity of various operational considerations during flight that influences safety and effectiveness.