Which action is taken first in a stab trim runaway situation?

In a stab trim runaway situation, the priority is to regain control of the aircraft and stabilize the situation as quickly as possible. Assuming manual control of the control wheel is a critical first step because it allows the pilot to directly manage the aircraft's pitch attitude and respond to any uncommanded movements caused by the stab trim malfunction. By using manual control, the pilot can counteract the effects of the runaway trim and ensure the aircraft remains on its desired flight path.

While other actions, such as pushing, holding, and releasing the STAB TRIM DISC, can be effective in stopping the runaway trim, they follow once manual control is established. Reducing engine thrust or engaging the autopilot, although potentially useful in other scenarios, do not directly address the immediate need to stabilize the aircraft in the face of uncommanded trim input. Therefore, regaining manual control takes precedence as the first action to ensure safety and effective management of the flight situation.