Scarce Pine to Palm cover flown on to Argentina from Miami with US stamps added. Mailed Aklavik March 14th. 1931 & flown to Miami via Fort McMurray & Pembina. Arrived Miami April 4th where 55 cents in US postage was added. Arrived in Buenos Aires April 13th. - see arrival back stamp - Only 37 pieces flown & the first one I've ever stocked. The scarcest Commercial Airways cover & in very fine condition.