What should be done if a pitch trim runaway occurs during flight?

During a pitch trim runaway, it is crucial to quickly and effectively manage the situation to maintain control of the aircraft. Pressing and holding the AP/TRIM disc button is the correct action because this button is specifically designed to disengage the electrical trim system. By doing this, you effectively stop any further trim actuation and regain control over the pitch of the aircraft.

This action is part of the correct procedures outlined for a pitch trim runaway and allows the pilots to stabilize the aircraft by manually controlling the pitch without interference from the automatic systems. It is essential, especially in a scenario where maintaining a controlled flight path is critical to avoid a dangerous situation.

In contrast, initiating an emergency landing immediately may not address the root cause of the problem and can lead to unnecessary escalation of the situation. Reducing power to idle does not directly address the trim runaway issue and could lead to other complications. Disconnecting the autopilot, while it may be a consideration, does not directly mitigate a trim runaway scenario as effectively as using the trim disc button. Thus, the correct action is to press and hold the AP/TRIM disc button to regain control.