3 cents Caribou (Brown) Hawker Overprint tied to April 12, 1919 "FIRST ATLANTIC AIR POST April 1919" attempted flight cover to England, the plan crashed into the sea and the mail was later salvaged, Liverpool may 31 arrival postmark at right, flap torn and small cover tear, the stamp is exceptionally fresh and well centered, a very rare flight cover (95 carried), very fine wth interesting letter discussing the two planes waiting to make the crossing, estimated by Eastern Auctions at US$30,000.00