Which of the following is NOT a valid reason for a pilot-in-command to deviate from an air traffic clearance?

A pilot-in-command is authorized to deviate from an air traffic clearance for several reasons that are typically related to maintaining safety and addressing immediate situations. Emergency situations, traffic avoidance, and weather conditions are all situations where deviations are necessary to ensure the safety of the aircraft and its occupants.

When facing an emergency situation, a pilot must prioritize the safety of the flight and may take actions that deviate from the planned route or clearance provided by air traffic control. Similarly, if there is a need to avoid other traffic in the airspace, a pilot may alter the flight path to prevent potential collisions, which is also in line with safety protocols. Weather conditions can necessitate changes in flight altitude or route if the current clearance exposes the aircraft to hazardous conditions such as turbulence or severe storms.

In contrast, adding an extra stop while en route does not qualify as an emergency or safety-related deviation. Such a change would typically require prior clearance from air traffic control since it impacts the planned route and affects coordination with other aircraft. This need for authorization underscores the importance of following air traffic clearances in non-emergency situations, as deviations should primarily focus on immediate safety concerns.