Austrian Airmail Overprints, 1918

Austria · 1918 · 10, 20, 40 Heller

Three Austrian definitive stamps featuring Emperor Franz Joseph I, overprinted in black with a biplane and the word 'FLUGPOST' for airmail service. The denominations are 10, 20, and 40 Heller.

These stamps were issued during the final year of World War I, marking one of Austria-Hungary's early forays into airmail service. The overprints transformed existing definitive stamps into specialized airmail issues, reflecting wartime innovation and the nascent development of aerial postal delivery.