Correct my mistakes In addition to the limitations placed over operation of state aircraft in a foreign territory, drones are limited by article 8 of the chicago convention which prohibits over flight by pilot aircraft by stipulating that: This would imply that drones, which by their very nature are pilotless, cannot be operated unless expressly authorized, over the territory of another state. sovereignty is a fundamental principe of international law of coexistence. Territorial integrity and inviolablity of borders are key attributes of state sovereignty over their airspace. Foreign aircraft need to take permission of the state concerned in order to transit or land in territorial.