The freedoms of the air are nine traffic rights that determine when a commercial airline may fly across, into, or within another country. They run from the basic right to overfly a foreign country without landing to the rarely granted right to operate purely domestic routes inside one. Every international flight exists because two or more governments agreed to exchange some combination of these rights, and the reason they have to agree at all traces back to a single sentence of treaty law: every nation owns the sky above its borders.
Why Permission Is Needed at All
The legal foundation is the Convention on International Civil Aviation, signed in Chicago in 1944 and catalogued as ICAO Document 7300.1International Civil Aviation Organization. Convention on International Civil Aviation – Doc 7300 Article 1 declares that every country has “complete and exclusive sovereignty over the airspace above its territory.”2United Nations Treaty Series. Convention on International Civil Aviation If the sky above France belongs to France, then a Brazilian airline needs France’s permission to cross it, land in it, or pick up passengers there. The nine freedoms are the vocabulary governments use when they negotiate that permission.
Two articles of the convention divide the traffic. Article 5 lets non-scheduled flights, such as charters, cross foreign territory or make non-traffic stops without prior permission, subject to conditions the overflown country may impose.3International Civil Aviation Organization. Convention on International Civil Aviation – Original Text Article 6 takes the opposite line for scheduled international service: no scheduled flight may operate over or into a country’s territory without that country’s specific permission. Almost everything about the nine freedoms flows from Article 6.
The First Two Freedoms: Overflight and Technical Stops
The first two freedoms are called technical because they do not involve carrying paying passengers or cargo to or from the country being crossed.
The First Freedom is the right to fly across another country’s territory without landing. Without it, a flight from South America to Europe might need to swing hundreds of miles off course to avoid West African airspace.
The Second Freedom is the right to land in a foreign country for a technical stop, typically to refuel, without picking up or dropping off any traffic. Refueling stops were essential in the early decades of aviation when aircraft range was limited, and they still matter for certain cargo operations and older aircraft types.
Both freedoms are widely available through the International Air Services Transit Agreement (IASTA), signed alongside the Chicago Convention in 1944. IASTA provides a multilateral exchange of the first two freedoms for scheduled international air services among its signatories.4International Civil Aviation Organization. Administrative Package for Acceptance of the International Air Services Transit Agreement Most countries have signed on, which makes overflight and technical landings the easiest permissions for airlines to obtain. Where IASTA doesn’t apply, these rights are negotiated bilaterally. Using a technical stop to board passengers when the authorization was refueling-only is treated as a violation and can trigger enforcement against the airline.
The Third and Fourth Freedoms: Home Country to Foreign Country and Back
The Third and Fourth Freedoms are the core of international airline service.
The Third Freedom lets an airline carry traffic from its home country to a foreign country. A U.S. airline flying passengers from New York to London is exercising a Third Freedom right.
The Fourth Freedom lets an airline pick up traffic in a foreign country and bring it home. The same U.S. airline flying passengers from London back to New York is using its Fourth Freedom.
Most bilateral air service agreements are built around exchanging these two freedoms in roughly equal measure. If Country A grants an airline from Country B the right to bring passengers into Country A, Country A’s own airlines typically expect the reciprocal right to carry passengers out of Country B. When the exchange is unbalanced, trade tensions follow. Open Skies agreements sidestep that problem by granting both freedoms without capacity restrictions and letting airlines set their own prices and schedules.5U.S. Department of State. Open Skies Agreements
The Fifth, Sixth, and Seventh Freedoms: Carrying Traffic Between Foreign Countries
Beyond the fourth, the freedoms describe increasingly ambitious ways of carrying traffic between two countries that are not the airline’s home. Grants become less common as you move up the list.
Fifth Freedom
The Fifth Freedom lets an airline carry passengers between two foreign countries, provided the flight originates or terminates in the airline’s home country. Singapore Airlines uses it to operate from New York JFK to Frankfurt and from Los Angeles to Tokyo Narita. Emirates uses it between New York JFK and Milan and between Newark and Athens. Each of those segments sits inside a longer route that begins or ends in the airline’s home country. For travelers, Fifth Freedom routes offer a chance to fly a premium international carrier on a segment where it would not otherwise be present; for airlines, they fill seats that would otherwise fly empty. Because the flight touches two foreign countries, both must consent, which is why Fifth Freedom routes tend to appear in Open Skies environments.
Sixth Freedom
The Sixth Freedom is not formally defined in any treaty. It describes what happens when an airline combines its Third and Fourth Freedom rights to move passengers between two foreign countries by routing them through its home hub. A traveler flying from São Paulo to Istanbul on a connecting itinerary through a Gulf carrier’s home base is being carried on a Sixth Freedom service. Because it is really just a combination of existing Third and Fourth Freedom rights, no separate grant is needed. Large hub-and-spoke carriers in the Middle East, Turkey, and Southeast Asia have built global networks on this model, and legacy carriers in Europe and North America have long argued that some of those competitors use subsidized routing to undercut direct services.
Seventh Freedom
The Seventh Freedom lets an airline operate a route between two foreign countries with no connection to its home country at all. A carrier based in Country A would fly passengers between Countries B and C on a service that never touches Country A. This is rarely granted for passenger service, because it puts a foreign carrier in direct competition with local airlines on routes those local carriers consider their own. Where Seventh Freedom rights are exchanged, it tends to be for cargo, where the political sensitivities are lower.
The Eighth and Ninth Freedoms: Cabotage
Cabotage rights let a foreign airline carry traffic between two points inside another country. Almost every nation guards these rights closely, treating domestic routes as reserved for domestically licensed carriers.
The Eighth Freedom, sometimes called consecutive cabotage, lets a foreign airline carry passengers between two cities in another country, but only as part of a route that begins in the airline’s home country. An airline based in Country A flies from its capital to City X in Country B, then continues to City Y in Country B, picking up and dropping off domestic Country B passengers on that second leg.
The Ninth Freedom, or stand-alone cabotage, goes further and lets a foreign airline operate purely domestic routes in another country with no home-country connection at all.
In the United States, federal law prohibits foreign civil aircraft from transporting persons or property between U.S. points for compensation.6Office of the Law Revision Counsel. 49 USC 41703 – Navigation of Foreign Civil Aircraft Only carriers holding a certificate of public convenience and necessity, which requires U.S. citizenship, may provide scheduled domestic air transportation.7Office of the Law Revision Counsel. 49 USC 41102 – Certificate of Public Convenience and Necessity Most other countries maintain similar prohibitions.
The major exception is the European Union. EU law lets any airline licensed in a member state operate routes within any other member state, including purely domestic routes. A French-registered airline can fly passengers from Munich to Berlin. This amounts to a full exchange of Eighth and Ninth Freedom rights among all EU members and is the most extensive liberalization of cabotage anywhere in the world.8European Parliament. Air Transport – Market Rules
Even countries that prohibit cabotage sometimes need foreign carriers to fill gaps during emergencies. In the United States, the Secretary of Transportation can grant a foreign airline a temporary exemption lasting up to 30 days to carry passengers between domestic points. The bar is high: the emergency must arise from unusual circumstances outside normal business, every effort must have been made to accommodate the traffic using domestic carriers’ resources, and the exemption must be necessary to avoid unreasonable hardship. If the emergency stems from a labor dispute, the exemption cannot give either side an unfair advantage.9Office of the Law Revision Counsel. 49 USC 40109 – Authority To Exempt These exemptions are renewable in 30-day increments as long as the emergency persists.
How Airlines Actually Get These Rights
Because the Chicago Convention left commercial rights to be negotiated separately, countries have built a web of bilateral air service agreements to decide which airlines can fly where. The 1946 Bermuda Agreement between the United States and the United Kingdom became the template that most early agreements followed, and the bilateral model still dominates: thousands of country-to-country deals sit behind the world’s international route map.
A standard bilateral covers which freedoms are exchanged, which airports can be served, how many flights per week each side’s airlines may operate, and which specific airlines are designated to use the rights. Open Skies agreements go further by removing government control over routes, capacity, and pricing; the United States has signed such agreements with over 100 partners.5U.S. Department of State. Open Skies Agreements They also typically let airlines set up sales offices in the partner country, handle their own ground services, and convert and repatriate earnings without restrictions.10U.S. Department of State. Open Skies Agreements – Fair and Equal Opportunity to Compete
Traffic rights on paper mean nothing unless an airline is eligible to use them. Bilateral agreements typically require each country to designate which of its airlines may exercise the negotiated rights, and eligibility usually turns on ownership and control. The traditional standard is that an airline be “substantially owned and effectively controlled” by nationals of the designating country. U.S. law caps foreign voting stock ownership at 25 percent and requires that a U.S. airline be under the actual control of U.S. citizens, with the Department of Transportation assessing compliance on a case-by-case basis roughly every five years.11U.S. Government Accountability Office. U.S. Airlines – Information on DOT Oversight of and Stakeholders Perspectives on Foreign Ownership Foreign airlines serving U.S. routes must in turn obtain a permit from the Secretary of Transportation, who must find that the airline is fit, willing, and able to provide the service and has been designated by its home government under an applicable agreement.12Office of the Law Revision Counsel. 49 USC 41302 – Permits of Foreign Air Carriers Other countries impose parallel requirements.
Why Holding a Freedom Isn’t Always Enough
An airline can hold every traffic right imaginable and still be unable to launch a route. At the world’s busiest airports, classified as Level 3 under the Worldwide Airport Slot Guidelines, an airline must hold a slot allocation before operating any flight. Slot allocation runs independently from traffic rights; having permission from two governments to fly a route gives no priority for a takeoff or landing window at a crowded airport. The system runs on historic precedence: an airline that uses its allocated slots at least 80 percent of the time keeps them for the next equivalent season, which lets incumbents lock up the most desirable times. A new entrant may have the legal right to fly but no practical way to land at peak hours.
Environmental compliance is becoming another cost layer on top of the freedoms. ICAO’s Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) requires airlines on international routes to monitor their emissions and offset growth above baseline levels, with a mandatory phase beginning in 2027 for routes between participating states. Sustainable aviation fuel mandates in the European Union, United Kingdom, Switzerland, and a growing list of Asian jurisdictions raise the cost of exercising traffic rights on affected routes without changing the rights themselves. For airlines planning a network, holding the freedom is only the first step; the slot and the compliance bill decide whether the route actually flies.