ALS, one page, 5.25 x 8, NASA letterhead, no date. Letter to "Mr. Glass," in full: "The dates of my 7 X-15 flights can be obtained from: Mr. Ralph Jackson, NASA, Box 273, Edwards, Calif. Sincere thanks for sending the photos." In fine condition.Armstrong was actively engaged in both piloting and engineering aspects of the X-15 program from its inception. He completed the first flight in the aircraft equipped with a new flow-direction sensor (ball nose) and the initial flight in an X-15 equipped with a self-adaptive flight control system. He worked closely with the designers and engineers in the development of the adaptive system, and made seven flights in the rocket plane from December 1960 through July 1962. During those flights he reached a peak altitude of 207,500 feet in the X-15-3, and a speed of 3,989 mph (Mach 5.74) in the X-15-1.Format: ALS