At which level does the English language proficiency certification start?

The correct answer is Level 4, which is significant in the context of the English language proficiency certification as it establishes a standard for pilots and air traffic controllers. This level is a crucial minimum requirement, as it ensures that individuals possess a sufficient command of the English language to effectively communicate in aviation operations.

Level 4 is recognized internationally and reflects the ability to handle routine situations, clear communications, and comprehensibility in stressful or unusual scenarios. This proficiency is vital for safety in aviation contexts, where misunderstandings can have critical consequences. Ensuring that all operational personnel meet this standard reinforces communication and operational safety within international aviation.

Lower levels, such as Levels 1, 2, or 3, do not meet the required competency and could lead to challenges in communication that could jeopardize flight safety. Therefore, establishing proficiency at Level 4 is a foundational aspect of aviation language requirements.