DS, signed “Hugh L. Dryden,” one page, 8 x 10, 1932. As president of the Institute of the Aeronautical Sciences, Dryden authorizes a Certificate of Membership to Eastern Air Lines. In part: “This officers and council of the Institute certify that Eastern Air Lines, Inc. has been elected a corporate member of the institute founded in 1932 to advance the scientific knowledge and the prestige of the aeronautical profession.” Countersigned by the institution’s executive vice president and secretary. A gold foil seal is intact. In very good condition, with a heavy strip of adhesive and paper residue at the top of the page. RRAuction COA.