Bilateral Air Service Agreements

What Are Bilateral Air Service Agreements?

Bilateral air service agreements (BASAs) are formal treaties negotiated between two sovereign states. Their main purpose is to regulate scheduled commercial air services connecting the two countries. BASAs outline key rights, such as which airlines are allowed to operate, the routes and frequencies permitted, and the conditions for market access. These agreements are central to the structure of international air transport.

Legal Framework and Freedoms of the Air

BASAs are grounded in the principles of the Chicago Convention. No scheduled international service can operate into another state's territory without explicit permission, typically granted through a BASA. The agreements define the so-called "freedoms of the air":

• Technical Freedoms: The right to overfly a state without landing (First Freedom) and the right to land for non-traffic purposes, such as refuelling (Second Freedom).
• Commercial Freedoms: Rights to carry passengers or cargo between the home state and the partner state (Third and Fourth Freedoms), and to carry traffic between the partner state and a third country (Fifth Freedom).

BASAs may also specify restrictions, such as prohibiting cabotage (domestic flights within the partner state by foreign airlines), which is protected under international law.

Registration and Oversight

All BASAs and similar international air agreements must be registered with ICAO, which maintains a global database. This ensures transparency and compliance with international standards. Within the European Union, additional frameworks like SERA harmonize rules for member states, but BASAs remain the primary tool for managing air services between non-EU countries.

Operational Impact

For airlines and pilots, BASAs determine which routes are legally available, what documentation is required, and the commercial opportunities in foreign markets. Violating BASA terms can result in denied entry, fines, or loss of operating rights.