Airspace not within any country’s territorial limit is considered international, analogous to the “high seas” in maritime law. However, a country may, by international agreement, assume responsibility for controlling parts of international airspace, such as those over the oceans.
Permanent two-way radio contact with ATC is required. Permission for using airspace is required except for the special cases listed in clause 114 of the Federal rules for using Russian air space. Class B is not used. Class C airspace is defined below 8,100 metres (26,600 ft) and allows IFR and VFR operations