Airmail, 1933, 50¢ "Chicago" Zeppelin Flight. Attractive flown cover, New York to Friedrichshafen via Chicago, franked with four examples of C18, purple flight cachet, red triangle 1933 Sudamerikafahrt cachet, green Friedrichshafen fancy cancel on reverse, Very Fine. Scott No. C18  Estimate $100 - 150. $0 (Image)