What should the flight crew do immediately if smoke occurs in the flight deck?

In the event of smoke in the flight deck, the appropriate immediate action for the flight crew is to don oxygen masks with 100% oxygen. This response is crucial because smoke can lead to reduced visibility and can also be harmful or even deadly due to inhalation. By using oxygen masks, pilots ensure they maintain adequate oxygen levels while also remaining capable of functioning effectively in a critical situation. This action helps to protect their health and enables them to continue to manage the aircraft safely.

In contrast, leaving the flight deck would potentially compromise the safety of the aircraft, especially if the situation escalates. Opening windows is not an option in most aircraft, as they do not have operational windows, and even if they did, it would be counterproductive during a smoke event. Turning off electronic devices is also not an immediate priority compared to addressing the issue of smoke inhalation and maintaining oxygen supply. Thus, wearing the masks is the most effective and immediate response in this scenario.