1936, 1. North America flight, handing in for transport Frankfurt with confirmation stamp "c", registered cover with 50 and 75 Pfg North America flight as well 2 M. airmail from "Hamburg 14.4.36" with arrival postmark New York from 9. May, although the sender adress about airship transport "to North America flight and return" bat and accordingly high franked, was the cover on normal alleys return transported, interesting document