Airmail Promotion Flights

Since 1923, Swiss philatelists combined with flying enthusiasts to produce a wide variety of mail carried aboard commemorative and promotional flights. This cover comes from the first such purely promotional flight at the military flying day exhibition at Basel on September 2, 1923.

Flight from Basel to Zürich; pilot: Hauptmann Rihner. Receiving Mark on reverse: Schweizer Flugpost 2.IX.23-21.