Commercial cover franked with 1924 5c scarlet 'San Martin' issue and 1928 25c chocolate 'Air' issue (SG 534 & 560) tied by VIA AEREA BUENOS AIRES cds dated 9 SEPT 1929. Addressed to SANTIAGO, CHILE with arrival cds on reverse. A very early example of commercial mail on this route which started with the First Flight on the 3rd September 1929.