What must pilots have in addition to valid passports when flying into Mexico?

When flying into Mexico, pilots are required to have English proficiency indicated on their pilot certificates. This requirement stems from the fact that English is the international aviation language, as mandated by the International Civil Aviation Organization (ICAO). Effective communication is essential for safety in aviation, especially in environments where pilots and air traffic control may be using different native languages. Therefore, possessing verified English proficiency ensures that pilots can effectively understand and respond to instructions and communications while operating in or near Mexican airspace.

The other options do not fulfill the necessary requirements for entry into Mexico. While a pilot's license is fundamental for operating an aircraft, it alone does not meet the international communication standards that could be critical during flights. An International Driver's License is irrelevant in the context of aviation operations. Similarly, while commercial insurance is important for overall flight operations, it is not specifically mandated for entry into Mexico in the same way that proficiency in English is required for safety and operational reasons.