What event occurs when the actuator lug is pulled up on the B61 nuclear bomb?

When the actuator lug is pulled up on the B61 nuclear bomb, it initiates the firing of the bomb's spin rocket. This is an important step in the bomb's deployment process, as it helps to ensure the bomb stabilizes in flight by creating a spin. The spin is critical because it provides aerodynamic stability, allowing the bomb to follow a precise trajectory toward the target.

The other options do not accurately describe the function of the actuator lug. Disarming the bomb, releasing its payload, and engaging the safety pin are distinct events that do not occur during the actuation of the spin rocket. Therefore, understanding the role of the actuator lug in the deployment of the B61 emphasizes its significance in the overall functioning of the bomb during its operational procedures.