Collection of 33 items signed by North American X-15 pilots, consisting mostly of covers but also including photos, letters, and books, with the signers as follows: Scott Crossfield (9), Joe Engle (3), Fitz Fulton (2), Pete Knight (3), Jack McKay, Forrest Petersen, Robert Rushworth (2), Milt Thompson (5), Joe Walker (2), and Bob White (3). Includes two group photos: one signed by Jim McDivitt, Frank Borman, Thomas McElmurry, Robert Buchanan, and William G. Schweikhard; and the other signed by Rushworth, Ralph Rund, Petersen, and Bob Hoover. In overall fine condition. Accompanied by an assortment of X-15 covers and early photos of the program’s aircraft and pilots, including Neil Armstrong.