China 1933, airmail issue depicting a Junkers F13 monoplane flying over the iconic Nankou Pass section of the Great Wall, with a denomination of 1 Chinese dollar in yellow-green. This airmail stamp was printed using gravure by the Chinese Bureau of Engraving and Printing and released on May 13, 1933. It belongs to the "Plane Over the Wall" series and features the narrow type with an image size of 41 x 22½ mm and full stamp dimensions of 43 x 25 mm. Perforated line 14 and unwatermarked, it showcases themes of aviation, mountainous landscapes, national monuments, and transport. This is a vertical strip of three stamps with clear circular cancels on each, showing full details and fine centering. The back reveals full gum with faint hinge remnants and a pencil note. Cataloged under Michel CN-IM 269, Scott CN-IM C18, Yvert et Tellier CN PA18, Stanley Gibbons CN-IM 429, and China Stamp Society CN-IM AM22. Estimate "$95 – 110"