Two total, both 6.5" x 3.5", n. p., postmarked June 21, 1931, reading "Round the World Flight of the 'Winnie Mae.'" Mounted to a board below the title "Letters carried on the 'Round the World Flight' by the 'Winnie Mae'" and framed to an overall size of 12" x 15". Toned. Wiley H. Post, an American pilot, and Harold C. Gatty, an Australian navigator, were the first to circumnavigate the world in a fixed-wing aircraft from June 23-July 1, 1931. Leaving Roosevelt Field in Long Island, New York, aboard the Winnie Mae, the flight took 8 days, 15 hours, and 51 minutes. The previous record of 21 days to fly around the world was held by the German dirigible Graf Zeppelin. Estimate: $400 – $500. Included in Heritage Auctions’ Historical Manuscripts Auction #6080, April 11, 2012, in New York.