Chicago Convention, 1944 and Airspace Sovereignty

The Chicago Convention, officially the Convention on International Civil Aviation, is the main international treaty that governs flying between countries. Its very first rule says that every country has complete and exclusive sovereignty over the airspace above its territory. In simple words, the sky above a country belongs to that country, just like its land. The Convention also set up the International Civil Aviation Organization (ICAO) and gave the world common rules for safe, orderly air travel.

Why does the world need it?

An aeroplane flying from Delhi to London crosses many countries in a few hours. Without shared rules, each country could set its own signals, its own safety standards and its own permission system. Pilots would not know which rules to follow, and accidents would be far more likely. The Convention is like a common traffic rulebook for the sky, so that a flight can move across many countries safely and predictably.

Where did it come from?

The first big treaty on flying was the Paris Convention of 1919, signed after the First World War. It already accepted that each country owns the air above it, and it set up a body called ICAN (International Commission for Air Navigation). During the Second World War, aircraft improved very fast. The Allied countries saw that a large passenger airline industry would grow after the war. So the United States invited countries to a conference in Chicago in late 1944.

• The Convention was signed in Chicago on 7 December 1944 by 52 countries.
• A temporary body, the Provisional ICAO (PICAO), worked from 6 June 1945 until the permanent body was ready.
• The Convention came into force on 4 April 1947, after enough countries had ratified it (formally confirmed it). ICAO was born on the same day.
• India signed on 7 December 1944 and ratified on 1 March 1947. So India is a founder member of ICAO.

What are its key articles?

The Convention has 96 articles. The ones UPSC can ask about are:

• Article 1: every state has complete and exclusive sovereignty over the airspace above its territory.
• Article 2: "territory" means the land and the territorial waters next to it. So a country's airspace also covers the sea up to its territorial limit (12 nautical miles under the law of the sea).
• Article 3: the Convention applies only to civil aircraft. State aircraft (used in military, customs and police services) are not covered by it.
• Article 3 bis: states must not use weapons against civil aircraft in flight. It was added by a protocol signed in Montreal on 10 May 1984, after the Soviet Union shot down Korean Air Lines Flight 007 in 1983. It came into force on 1 October 1998.
• Article 5: foreign aircraft on non-scheduled flights (for example, charter flights) may fly in and make stops for non-traffic purposes, such as refuelling, without asking permission in advance.
• Article 6: scheduled international air services (regular airline routes) need the special permission of the country they fly over or into. This is why airlines need deals between governments, called air services agreements.
• Article 9: a state may restrict or ban flying over parts of its territory for military need or public safety. Under Article 9(b), it may also, in exceptional circumstances or an emergency, temporarily restrict flying over the whole or any part of its territory. The condition is that such limits apply without distinction of nationality, meaning to aircraft of all other states equally.
• Article 17: an aircraft has the nationality of the country in which it is registered. This is why the Pakistani NOTAM talks about "Indian registered aircraft".
• Article 37: ICAO adopts international standards. These are placed in Annexes to the Convention. There are now 19 Annexes, holding the Standards and Recommended Practices (SARPs).
• Article 84: if two states disagree about the Convention, they can take the dispute to the ICAO Council. A state can appeal the Council's decision to the International Court of Justice (ICJ) or to an arbitral tribunal.
• Article 89: in war, the Convention does not limit the freedom of action of the states involved. The same applies to a state that declares a national emergency and informs the ICAO Council.

How does flying across a country actually work?

Owning the sky does not mean a country refuses all foreign flights. It means foreign flights need its consent. Consent comes in three main ways:

1. The Convention itself gives non-scheduled flights some rights (Article 5).
2. The International Air Services Transit Agreement, 1944 (also signed at Chicago, in force from 30 January 1945) gives scheduled flights of member states the right to fly over without landing and to land for non-traffic reasons. It is called the "Two Freedoms Agreement". Both India and Pakistan are parties to it.
3. Bilateral air services agreements between two governments decide which airlines may carry passengers between them, on which routes and how often.

What are the "freedoms of the air"?

These are the standard set of rights an airline may get in a foreign country. The first five are named in the 1944 Chicago agreements; the later ones are informal names used in bilateral deals.

• First freedom: fly over a foreign country without landing.
• Second freedom: land in a foreign country for non-traffic reasons, such as refuelling or repairs, without picking up or dropping passengers.
• Third freedom: carry passengers from your own country to a foreign country.
• Fourth freedom: carry passengers from a foreign country back to your own country.
• Fifth freedom: carry passengers between two foreign countries on a flight that starts or ends in your own country.
• Sixth to ninth freedoms: further rights, such as linking two foreign countries through your home hub, or flying wholly inside another country (called cabotage, the eighth and ninth freedoms). These are rare and depend fully on bilateral deals.

An airspace ban like Pakistan's is, in effect, the withdrawal of the first freedom for Indian aircraft.

FIRs and NOTAMs: the working tools

The whole world's sky is divided into Flight Information Regions (FIRs). In each FIR, one country gives flight information and alerts to aircraft. FIR lines often follow national borders, but over the high seas a country may manage an FIR beyond its own territory, without owning that sky. India has four main FIRs: Delhi, Mumbai, Kolkata and Chennai, managed by the Airports Authority of India.

Pakistan has two: Karachi and Lahore. Any change, such as a closed route, a missile test area or a closed airspace, is announced through a NOTAM. ICAO's Annex 15 (Aeronautical Information Services) lays down how NOTAMs are written and shared.

India's position and Indian examples

• India follows the Convention through national law. The Aircraft Act, 1934 was replaced by the Bharatiya Vayuyan Adhiniyam, 2024, in force from 1 January 2025. The Directorate General of Civil Aviation (DGCA) is the safety regulator.
• 1971: after an Indian Airlines plane was hijacked to Lahore and destroyed, India suspended overflights by Pakistani civil aircraft. Pakistan complained to the ICAO Council under Article 84. India argued the Council had no power to hear the case. In Appeal Relating to the Jurisdiction of the ICAO Council (India v. Pakistan) (18 August 1972), the ICJ held that the ICAO Council did have the power to hear Pakistan's complaint, and rejected India's appeal.
• 2019: after the Pulwama attack (14 February 2019) and the Indian Air Force strike at Balakot, Pakistan closed its airspace from late February 2019. It fully reopened it to civil traffic only on 16 July 2019. The government told Parliament that Indian airlines lost about ₹549 crore, of which Air India's share was about ₹491 crore.
• 2025 onward: closures by both sides after the Pahalgam attack, renewed every month through NOTAMs.

Commonly confused concepts

• Chicago Convention vs Paris Convention (1919): Paris was the first air-law treaty and created ICAN. Chicago (1944) replaced it and created ICAO.
• Civil aircraft vs state aircraft: the Convention covers only civil aircraft. Military, customs and police aircraft are state aircraft, outside its rules.
• Article 5 vs Article 6: Article 5 is for non-scheduled flights (some rights without prior permission). Article 6 is for scheduled airline services (special permission always needed).
• Airspace vs FIR: sovereign airspace is the sky a country owns. An FIR is only a service area, and it can extend over the high seas that no country owns.
• Chicago Convention vs Tokyo, Hague and Montreal Conventions: the Chicago Convention sets the basic rules of flying. The Tokyo Convention (1963), Hague Convention (1970) and Montreal Convention (1971) deal with crimes on board, hijacking and attacks on aircraft.

Issues, criticism and the way forward

• Nationality-based bans: Article 9 asks that restrictions apply to all foreign aircraft equally. Bans aimed at one country's aircraft are therefore debated. States that impose them usually rely on security grounds, on Article 89 (war or declared national emergency) or on suspending the Transit Agreement with that country. Legal experts note that terms like "emergency" and "public safety" are not defined in the Convention, so each side interprets them in its own favour.
• Cost to passengers and airlines: longer routes mean more fuel, longer flying time, higher fares and, on long routes, extra stops. The country closing its airspace also loses the fees that foreign airlines pay for using its air traffic services.
• Weak enforcement: ICAO can hear disputes, but it has no police or army to enforce decisions. Its 2025 ruling holding Russia responsible for the 2014 MH17 shoot-down was its first decision on the merits of a dispute between governments, and Russia rejected it.
• Way forward: experts suggest keeping civil aviation separate from political disputes, using ICAO's dispute system more, and clearer international guidance on when emergency closures are allowed and how long they may last.

Concepts to Know

• Sovereignty: a country's full and final power over its own territory. No outside power can give orders there.
• Ratification: the formal step by which a country confirms it will be bound by a treaty it has signed.
• Territorial waters: the belt of sea up to 12 nautical miles from a country's coast, which belongs to that country.
• Scheduled vs non-scheduled flight: a scheduled flight runs on a fixed, published timetable, like a daily airline service. A non-scheduled flight, like a charter or private flight, does not.
• NOTAM: a short official notice to pilots and airlines about any change or danger in airspace, such as a closed route or runway.
• Arbitral tribunal: a panel of neutral experts that both sides agree to, which decides a dispute outside a regular court.