8x10 philatelic EAFB document postmarked for the 35th anniversary of the first supersonic flight handsigned by 6 ! original X-1 testpilots : Goodlin, Johnston, Yeager, Champine, Griffith, Crossfield plus Mrs. Joe Walker and Jack Russell. RARE with Johnston, Goodlin and Yeager on one piece !!! (as they didn't like to sign when someone else of the three was present).