What should be done immediately upon detecting smoke in the cockpit during flight?

The correct action to take immediately upon detecting smoke in the cockpit during flight is to land at the nearest airport. This is crucial because smoke in the cockpit poses an immediate threat to flight safety, potentially affecting visibility and the functioning of instruments. Landing as quickly as possible minimizes risk to the crew and passengers and ensures that any potential fire can be addressed on the ground with proper emergency response resources.

While notifying air traffic control is also an important step, it can be performed simultaneously or immediately after initiating a diversion to the nearest airport. Addressing the smoke and ensuring a safe landing takes priority. Performing in-flight troubleshooting could lead to delays in landing, which elevates the risk of worsening conditions. Evacuating the aircraft is not feasible while still in the air, as it could endanger those on board. Therefore, prioritizing a safe landing is the most effective response in this critical situation.