What is the purpose of the "right of passage" principle in international aviation law?

The "right of passage" principle in international aviation law primarily serves to guarantee freedom of transit over international airspace. This principle is grounded in the need for nations to allow aircraft to traverse their airspace without undue restrictions, promoting safety and efficiency in global air transportation. The right of passage reflects the notion that airspace, especially that which is international, should be accessible to all nations' aircraft, facilitating international connectivity and cooperation.

By ensuring that aircraft can freely navigate through international airspace, this principle helps prevent unilateral actions by any single state that could disrupt global air travel. It is critical for promoting international commerce, tourism, and diplomatic relations. This concept is also reflected in various international treaties and agreements, which reinforce the importance of unhindered transit for all countries' air services.

In contrast, the other options imply restrictions or control that contradict the fundamental notion of freedom of transit that the "right of passage" is meant to uphold. Restrictions on air travel, visa requirements, or enforcement of tariffs would inhibit the very freedom that the principle seeks to protect.