Printed 'American Consular Service' cover franked with 1929 3c purple, 1930 6c red AIR issue & 1927 1c olive green TAX issue (SG 230, 223 & 254) tied by GUATEMALA CITY cds's dated JUN 27 1930. Flown on the inaugural flight for the GUATEMALA CITY - COBAN domestic route with boxed 'INAUGURACION DEL CORREO AEREO DE GUATEMALA A COBAN' cachet in purple with 'Coban' inserted in manuscript. Various Guatemala City transit marks and COBAN arrival cds dated JUL 1 1930 on reverse. (Muller #36, Goodman #AM28a)