Question: In what directional situation in Australia would one have found the main base of operation for the Aero-Tropics Air Services?
Sentence (from "Freedoms of the air"): The freedoms of the air are a set of commercial aviation rights granting a country's airlines the privilege to enter and land in another country's airspace, formulated as a result of disagreements over the extent of aviation liberalisation in the Convention on International Civil Aviation of 1944, known as the Chicago Convention.
Relevant evidence: No