Freedoms of the air

The freedoms of the air are a set of commercial aviation rights granting a country's airlines the privilege to enter and land in another country's airspace, formulated as a result of disagreements over the extent of aviation liberalisation in the Convention on International Civil Aviation of 1944, known as the Chicago Convention. The United States had called for a standardized set of separate air rights to be negotiated between states, but most other countries were concerned that the size of the U.S. airlines would dominate air travel if there were not strict rules. The freedoms of the air are the fundamental building blocks of the international commercial aviation route network. The use of the terms "freedom" and "right" confer entitlement to operate international air services only within the scope of the multilateral and bilateral treaties (air services agreements) that allow them.

The first two freedoms concern the passage of commercial aircraft through foreign airspace and airports, the other freedoms are about carrying people, mail and cargo internationally. The first through fifth freedoms are officially enumerated by international treaties, especially the Chicago Convention. Several other freedoms have been added, and although most are not officially recognised under broadly applicable international treaties they have been agreed to by a number of countries. The lower-numbered freedoms are relatively universal while the higher-numbered ones are rarer and more controversial. Liberal open skies agreements often represent the least restrictive form of air services agreements and may include many if not all freedoms. They are relatively rare but examples include the recent single aviation markets in the European Union and between Australia and New Zealand.

Freedoms of the air apply to commercial aviation. The terms 'freedom' and 'right' are a shorthand way of referring to the type of international services permitted between two or more countries. Even when such services are allowed by countries, airlines may still face restrictions to accessing them by the terms of treaties or for other reasons.

The first and second freedoms grant rights to pass through a country without carrying traffic that originates or terminates there and are known as 'transit rights'. The Chicago Convention drew up a multilateral agreement in which the first two freedoms, known as the International Air Services Transit Agreement (IASTA) or "Two Freedoms Agreement", were open to all signatories. As of mid-2007, the treaty was accepted by 129 countries.

...
Wikipedia