The use of the term state aircraft is recognised in international law. I refer the Deputy to the Chicago Convention on International Civil Aviation of 1944, which Ireland ratified in 1946. Article 3 (a) of that convention states the the convention "shall be applicable only to civil aircraft, and shall not be applicable to State aircraft".
Article 3 (b) of that convention goes on to define state aircraft as "aircraft used in military, customs and police services." The term state aircraft is, then, an internationally recognised term which can be applied equally to Irish and foreign aircraft.
As regards the second part of the Deputy's question, the UN Convention on the Law of the Sea distinguishes between merchant ships and government ships, although it does not define the latter. The Mercantile Marine Act, 1955, which governs the ownership and registration of Irish ships, uses the term State owned rather than Government ship. The Act defines a State-owned ship as a ship wholly owned by the Government or a Minister of State.
The term state ship, as used by the Deputy, might be used to refer to a wider category of ships, that is, those owned or operated by a state. Such ships are usually entitled to certain immunities under international law. For example, Article 96 of the UN Convention on the Law of the Sea provides that ships owned or operated by a state and used only on government non-commercial service shall, on the high seas, have complete immunity from the jurisdiction of any state other than the flag state.
