Article XIII

This Convention shall be open for signature in Montreal on 1 March 1991 by States participating in the International Conference on Air Law held at Montreal from 12 February to 1 March 1991. After 1 March 1991 the Convention shall be open to all States for signature at the Headquarters of the International Civil Aviation Organization in Montreal until it enters into force in accordance with paragraph 3 of this Article. Any State which does not sign this Convention may accede to it at any time.

This Convention shall be subject to ratification, acceptance, approval or accession by States. Instruments of ratification, acceptance, approval or accession shall be deposited with the International Civil Aviation Organization, which is hereby designated the Depositary. When depositing its instrument of ratification, acceptance, approval or accession, each State shall declare whether or not it is a producer State.

This Convention shall enter into force on the sixtieth day following the date of deposit of the thirty-fifth instrument of ratification, acceptance, approval or accession with the Depositary, provided that no fewer than five such States have declared pursuant to paragraph 2 of this Article that they are producer States. Should thirty-five such instruments be deposited prior to the deposit of their instruments by five producer States, this Convention shall enter into force on the sixtieth day following the date of deposit of the instrument of ratification, acceptance, approval or accession of the fifth producer State.

For other States, this Convention shall enter into force sixty days following the date of deposit of their instruments of ratification, acceptance, approval or accession.

As soon as this Convention comes into force, it shall be registered by the Depositary pursuant to Article 102 of the Charter of the United Nations and pursuant to Article 83 of the Convention on International Civil Aviation (Chicago, 1944).