Cover franked with block of four 1924 5c scarlet 'San Martin' issue (SG 534) tied by VIA AEREA BUENOS AIRES cds's dated 18 JUN 1926 with manuscript 'Correo Aereo' at top left. Addressed to MONTEVIDEO, URUGUAY with arrival cds dated the same day on reverse. This cover was flown by the Junkers Mission that ran the Buenos Aires - Montevideo route between March 1926 and October 1927. Scarce.