4. In addition, so long as airfields remain available south of the DON, the Germans will use transport aircraft, and possibly also other types diverted for the purpose, for maintenance of the forces in North CAUCASIA and for evacuating personnel and certain types of equipment. 5. (a) (b) (c) Possible Routes YEISK across the Gulf of TAGANROG East of a line YEISK MARIUPOL, the sea of AZOV remains frozen hard until the middle of March, its climax being the first days of February. A thickness of ice of at least three feet can be counted upon during this period.