Most crewmembers arrived at Beale with either an Air Force secret or top-secret security clearance. The SR-71 program, however, was further compartmentalized and called for a Special Access Requirement security clearance, a rare classification reserved only for highly sensitive military programs. The name of the special clearance was called “Senior Crown.” It was issued only to those who were on a need-to-know basis about the SR-71 program, from maintenance troops to the clerk typist in the squadron. The SR-71 aircraft’s flight manual (called the “Dash-1”) and flying checklist were classified secret NOFORN (no foreign dissemination). To control the large volume of classified documents issued to crewmembers, one entire wall of the squadron administration room was filled with large, five-drawer security safes. This was the crewmember’s first introduction to an increasing maze of combination locks, cipher codes, and secrets he needed to memorize to fly a mission, or in some cases, just to go to the bathroom!
This first appeared in Aviation Geek Club here.