Cover franked with 1924 1c green and pair 2c carmine 'Arms' issue and 1930 2 x 5c on 10c orange AIR issue (SG 199/200 & 238) tied by PANAMA cds dated MAR 10 1930. Flown on the PANAMA - COSTA RICA first flight with boxed 'AGENCIA POSTAL DE PANAMA PRIMER VUELO PANAMA - COSTA RICA' first flight cachet in pink. Addressed to SWEDEN with COSTA RICA arrival cds on front dated 11 MAR 1930 and SWEDISH arrival cds also on front. (Muller #38)