What is the first action to take during an emergency engine shutdown on the ground?

The first action during an emergency engine shutdown on the ground is to turn the Power Control Lever (PCL) to the OFF position. This step is crucial because it effectively cuts off fuel supply to the engine, which is essential in preventing any further fuel flow that could exacerbate an emergency situation. By immediately placing the PCL in the OFF position, the pilot can ensure that the engine is no longer generating thrust and can also begin to control any potential fire hazard or other complications stemming from an uncontrolled engine state.

The other actions listed, such as pulling the firewall shutoff handle, applying brakes, or maintaining a minimum airspeed, are important but serve as follow-up actions in the overall emergency response sequence. They come into play after the initial step of shutting down the engine has been enacted, highlighting the critical nature of first addressing the source of the emergency to secure the aircraft's safety effectively.