Registered airmail cover franked with 1925 15c grey USA issue with 'CANAL ZONE' overprint and pair 1929 10c on 50c mauve AIR surcharge issue (SG 92 & 124) tied by BALBOA cds dated APR 30 1930. Flown on the FAM 5 Cristobal - MIAMI first flight by Charles Lindbergh with illustrated first flight cachet on front and transit & arrival cds's on reverse. (AAMC #CZ55d, Muller #37)