What is the primary consequence of RPM decay in helicopter blades?

The primary consequence of RPM decay in helicopter blades is the loss of lift. Helicopter rotor blades rely on a specific rotational speed (RPM) to generate adequate lift. When RPM decreases, the angle of attack may become insufficient to maintain lift, leading to a reduction in the helicopter’s ability to stay aloft. This can cause significant issues during flight, including the potential for an uncontrolled descent. The blades must maintain their designed rotational speed to ensure that the aerodynamic forces acting on them are adequate to support the weight of the helicopter and to perform necessary maneuvers safely.

In contrast, an increase in lift occurs when RPM is adequately maintained or increased, while stability is generally affected by how well the rotor system is functioning. Improvement in maneuverability is also dependent on maintaining proper rotor speed, as lower RPM could hinder the ability to respond to control inputs effectively. Therefore, RPM decay primarily results in a loss of lift, affecting the helicopter’s overall performance and safety.