Charles A. Lindbergh & E.L. Sloniger Signed "Lindbergh Again Flies the Air Mail" Flown Cover, PSA/DNA Slabbed & Graded Mint 9!A "Lindbergh Again Flies the Air Mail" First Day Cover signed by two famous twentieth century aviators: Charles A. Lindbergh (1902-1974), as "Charles A. Lindbergh / May, 1940" at bottom left; and Eyer L. Sloniger (1896-1969), as "EL Sloniger" at upper left. Bearing a two-toned horseshoe-shaped hand-stamped cachet at left and a cancelled ten-cent Lindbergh air mail stamp in the postage section. With two hand-stamps from Springfield, Illinois and St. Louis, Missouri dated February 21, 1928. The envelope is addressed to "Mr. H.A. Borgmann" of St. Louis. PSA/DNA slabbed and graded Mint 9. The envelope measures 6" x 3.5" while the slab measures 9.5" x 4.5."Lindbergh flew between St. Louis and Chicago in late February 1928 to commemorate his early flying days as a nondescript Midwestern air mail carrier. This was nearly a year after his record-breaking solo non-stop transatlantic flight from New York to Paris in the spring of 1927.Eyer L. "Slonny" Sloniger piloted the first scheduled commercial flight in the United States, and later worked for American Airlines. Sloniger had evaded almost certain death aboard the "Miss Doran," a contender in the ill-fated August 1927 Dole Air Race. By losing a coin toss to fellow pilot John "Auggy" Pedlar, Sloniger forfeited the pilot's seat; Pedlar, his navigator, and passenger were never seen again.Although these horseshoe covers are not particularly unique, those signed by Lindbergh are quite desirable, and the addition of Sloniger's signature should increase interest among aviation collectors.This item comes with a Certificate from John Reznikoff, a premier authenticator for both major 3rd party authentication services, PSA and JSA (James Spence Authentications), as well as numerous auction houses.WE PROVIDE IN-HOUSE SHIPPING WORLDWIDE!