Chicago Convention
Early Conventions
The first major Convention on Aviation was the Paris Convention on the Regulation of Aerial Navigation 1919. In effect, it codified and established international law principles on air space convention. It acknowledged and recognised the exclusive sovereignty of States over and in respect of their airspace.
The Convention was a precursor of the Chicago Convention 1944. It established some important principles and bodies. It established the National Air Navigation Commission for the purpose of developing and maintaining technical standards internationally. It dealt with airworthiness and certificates of competency, and many of its key principles survived in the later Chicago Convention.
In America, the Havana Convention in 1926 and the Ibero-American Convention in 1928. followed may of the principles of the Paris Convention on the American continents, although the United States did not ratify the Paris Convention. Transatlantic flight was not a feature of the era, and the United States did not wish to ratify a treaty which they perceived was in European interests.
Adoption of the Chicago Convention
In contrast, the Chicago Convention in 1944 was signed as a worldwide Convention for the purpose of development of international civil aviation generally, to avoid friction in cooperation between States, provide for the development of international civil aviation in a safe and orderly manner on the basis of equality of opportunity and operate it soundly and economically.
Its adoption coincided with the establishment of the United Nations and the era of Post-War international law. The Convention was passed in conjunction with and at the same time as the General Agreement on Tariffs and Trade. The ICAO is affiliated with the United Nations and seeks to enhance technical cooperation and to some extent to resolve disputes.
The Convention reaffirmed the principle of State sovereignty in airspace. It seeks to coordinate and harmonise aviation to the minimum extent necessary to permit international air transport services.
The Convention provides international standards for pilots’ licences and airworthiness certificates. The Convention is relatively neutral in terms of regulation for economic purposes.
Freedoms and Further Agreements
At the time the Convention was made and for many years afterwards, states’ regulation of the economy was extensive. The schedules to the Convention allowing for various freedoms and rights, which would have opened up international aviation to air carriers to operate passengers and cargo globally, were ratified by a handful of States, only.
Scheduled international air services should not be operated over the territory of a State without its authorisation. Each State may apply its laws and regulations in relation to admission to and departure of aircraft from its territory and the operation and navigation of the aircraft while on the territory, provided such laws and regulations are consistent with the Convention and are applied without distinction as to nationality.
Air services became and remained largely subject to many bilateral agreements in relation to licensing of operating particular routes, which States were not willing to concede control. The Convention was however, in itself relatively neutral in terms of economic liberalisation or regulation of the market. In effect, it has survived the era of both regulation and later liberalisation.
Although it reaffirmed State sovereignty over its air space, the Convention did not deal with sovereignty in the upper stratosphere, which was dealt with by later treaties.   Treaties recognise up to approximately 62 miles above the earth as where the atmosphere ends. This is generally accepted as a limit of sovereignty. Other treaties, such as the Outer Space Treaty 1967, provide open rights for all mankind in relation to outer space.
Principles of Aviation Regulation
Aircraft operating within the territory must obey aviation laws and regulations and ensure that the aircraft is registered. States must ensure that aircraft registered in their territory obey the regulations of other states over which they fly.
The Convention allows states for reasons of military necessity and public safety to establish restricted or prohibited zones over their territories, provided that limitations are applied uniformly to the airlines of the Convention’s contracting parties.
Exceptionally, States may temporarily restrict or prohibit flying over the whole or any part of its territory where public safety so requires. This prohibition must be applied uniformly to all States.
States are obliged to keep their aviation regulations uniform to the extent possible, in accordant with those established by the Convention. As well as covering basic principles, they provide for the permissible scope of customs, searches, clearance, disease and other controls that may be taken.
States may levy non-discriminatory charges for the use of airport,  air navigation and air traffic management facilities. Charges may not be imposed for the use of airports and navigations in relation solely to flying in and out of a territory.
Charges may only recover the actual costs of providing the relevant facilities. Controversy has arisen as to the extent to which environmental charges may be levied, where not specifically related to the cost of providing services.
Various Regulation
There is a provision for exemption from excise and sales tax for aircraft stores, fuel, and spare parts on international flights that are retained and kept until their departure.
There are special provisions providing for exemptions from infringement of patents by foreign aircraft while in state air. This applies in respect of any construction mechanism, parts, or accessories of the aircraft which may infringe patent design or models granted in the state.
States must provide air traffic navigation services to aircraft of other states that they permit in or over their territory. The standards must be harmonised in accordance with recommendations established under the Annexes to the Convention.
Where an aircraft is in distress or an incident or accident occurs, the State in which it is situated is to provide assistance and undertake an inquiry, if necessary.
The Convention provides uniform rules in relation to documentation that aircraft must carry in transit. It provides for technical specifications for aircraft radio equipment and minimum standards for recognition of aircraft and pilot licensing.
Registration
States may establish their own registration law.
The Convention deals with the registration of aircraft. Aircraft have the nationality of the State in which they are registered. The state of registration’s laws govern, provided that once it enters the airspace of another State, it complies with that State’s navigational operational rules.
Aircraft must bear the appropriate nationality and registration marks. States must furnish information to the ICAO and other states in relation to registration and ownership of any particular aircraft registered in their territory in accordance with the reporting standards prescribed by the ICAO.
An aircraft may be registered in one state only. Airlines may register individual aircraft in different states and commonly do so. Registration does not necessarily equate with the relevant airline’s ownership or place of establishment. Bilateral agreements may make requirements in relation to the nationalities of the carriers.
Cabotage
The doctrine of cabotage prevents foreign airlines from providing point to point services within a State. Provision may be found in bilateral treaties. Cabotage reflects the historic domestic position whereby states regulated their domestic maritime traffic.
The Chicago Convention acknowledges the right of States to refuse permission to aircraft of other contracting States to take on its territory, passengers, mail and cargo carried for remuneration and destined for another point within the State’s territory.
The Convention seeks to uphold cabotage by prohibiting States from entering arrangements which specifically grant the exclusive right of cabotage to another state or the airline of another state. States are obliged not to seek such exclusive privilege from another State.
Cabotage remains controversial and is inconsistent with the general principles of competition. It remains strong in international aviation law, notwithstanding the liberalisation of trade generally and, in particular, in the aircraft industry since the Convention.
Certain countries have unilaterally renounced cabotage. Many states unilaterally allow foreign-owned airlines to provide internal services. It may be avoided by the establishment and licensing of subsidiaries and would not operate to limit foreign ownership of domestic airlines. In the narrow sense, it applies to foreign providers providing internal domestic services without establishing a subsidiary or place of business. Domestic laws may make provisions relating to foreign ownership.
Regulations
The Irish Air Navigation and Transport Act 1946 made provision for approval and giving the force of law to the Chicago Convention. The Minister was entitled to prescribe the authority to exercise the powers under the Chicago Convention.
Regulations may make provision may be made for
- licensing and inspecting aerodromes,
- access and inspection,
- prohibiting the unlicensed use of aerodromes,
- providing for the manner of renewal of certificates and other licences,
- examination and tests to be undergone and the forms of any such certificates or licence.
- the registration of aircraft in the state.
- conditions for passenger carriage.
- conditions for goods carriage
- sale of charges at licensed aerodromes, providing for exemptions, providing for fees,
- control of aerial lighthouses,
- lights, similar apparatus.
- making of signals and communication to aircraft.
Provision was made for prohibited areas in respect to which it would be unlawful for aircraft to fly. Provision was made for signals to be given to such aircraft requiring compliance, and powers were given to compel compliance, including firing at such aircraft.
Penalties were provided in respect of any breach of regulations prescribed by the Minister. It is an offence to obstruct or impede any person exercising the performance of powers and duties on behalf of the Minister. A failure to comply with the requirements of regulations is an offence. The owner or hirer of an aircraft and also the pilot or commander are deemed to have breached the regulations.