1960's 25th Air Division and Seattle Air Defense Sector complex

The 25th Air Division (right) and Seattle Defense Sector (left) complex were built in the late 1950's and became operational in January 1960 on McChord Air Force Base, Washington. The facility complex, known as the "blockhouse," housed the world's two largest digital computers at the time. Radar sites around the Pacific Northwest feed information into the computers, which solved problems of position, speed, altitude, and armament for the interceptor directors, who in turn guided pilots to targets. The air defense system inside, known as the semi-automatic ground environment (SAGE), wasn't completely automated. The final decisions were made by Airmen, which were the vital element in the defense system. (Courtesy photo)

PHOTO BY: Kimberly D. Burke
VIRIN: 231026-Z-YA179-2001.PNG
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