In case of instrument failure, what is the best course of action a pilot should take?

In the context of handling instrument failure, notifying air traffic control immediately is a vital step for several reasons. Communication with air traffic control provides the pilot with immediate support and guidance. They can provide crucial information about weather conditions, nearby airports, and traffic, all of which are important during an instrument failure. Air traffic control can help prioritize the aircraft's landing, ensuring a safer outcome for the flight.

By informing air traffic control, the pilot can also receive assistance in determining the best next steps, whether that involves directing the aircraft to divert to the nearest airport or providing support for emergency procedures. This coordination is essential for maintaining safety, both for the aircraft in question and for other aircraft operating in the vicinity.

While other options like diverting to the nearest airport or flying at a lower altitude may also be reasonable actions in some circumstances, the immediate priority is to communicate the situation to air traffic control, which enhances situational awareness and safety during the critical moments following instrument failure.