21.3.1930. Syros - Athens. First Flight by Aero Espresso. Cover to Athens with special triangular commemorative cachet "AEΡΟΠΟΡΙΚΗ ΣΥΓΚΟΙΝΩΝΙΑ*ΕΛΛΑΔΟΣ - ΔΩΔΕΚΑΝΗΣΩΝ*1930*ΠΡΩΤΗ ΠΤΗΣΙΣ" in red, canc. "ΣΥΡΟΣ*21.ΜΑΡ.30", arr. "ΑΘΗΝΑΙ*21.ΜΑΡ.30". (Hellas FFC87A).