Air Mail service introduced due to frozen waters across the belts, airmail letter with two 10 øre wavy-line and 20 øre brown CHR X (round corner) on letter from Copenhagen 18 February 1922 to Aalborg (arriving 20.2.1922), paying 20 øre letter rate and 20 øre Air Mail charge. The plane flew between Aarhus-Samsø and Kalundborg. The Air Force established a tent camp at Gisseløre near Kalundborg and an “Airport” was made directly on the ice.