Cover franked with 1923 5c claret and 1929 block of six 5c orange yellow SCADTA issue (SG 396 & 56) tied by BOGOTA SCADTA cds's. Addressed to PEDRO MIGUEL, CANAL ZONE with fine strike of 'PANAMA-COLOMBIA-ECUADOR USE THE SCADTA AIRWAY SYSTEM SAVES ABOUT 10 DAYS Information and stamps through BOYD BROS PANAMA CITY' Panamanian consular agents cachet in blue on reverse with blue BARRANQUILLA transit cds and CRISTOBAL CANAL ZONE arrival cds. Very scarce.