What action should be taken in response to a "SIDE STICK FAIL" alert?

When faced with a "SIDE STICK FAIL" alert, the appropriate action is to utilize the operable side stick and press and hold the AP/PTY pushbutton for 30 seconds. This action is crucial because it allows the pilot to engage the autopilot in a way that can stabilize the aircraft using the remaining functional control.

The AP/PTY pushbutton is designed to initiate a configuration that assists the pilot in managing the aircraft through the failure, providing better control and reducing pilot workload. Holding the button for an extended period allows systems to reconfigure and ensure that the operable side stick is prioritized for use.

In this context, the other responses do not adequately address the immediate need to control the aircraft following a side stick failure. Switching to backup controls is not the immediate priority because utilizing the remaining operable side stick is a more direct solution. Landing as soon as possible may be considered, but it is not the first action to take; instead, the focus should be on maintaining control and assessing the situation. Notifying ground control before takeoff is not relevant in the context of responding to an in-flight emergency.