When the Vietnam War began to escalate, the United States Air Force changed the name of Air Defense Command to Aerospace Defense Command and lost most of its experienced pilots and maintenance personnel to Tactical Air Command. After Russia's MIG-21 appeared in Southeast Asia, TAC needed an aircraft to match its capabilities, so the new F-4 Phantom Interceptor, originally scheduled for ADC and still in the design stage, was converted into an attack fighter and given to TAC. To breach the gap after losing the F-4, ADC's aging F-106 Delta Dart Interceptor underwent structural modifications to extend its active life to an astonishing 8000 flight hours, more than designers ever intend for a first line interceptor. Hoping for better days, the unsung heroes of the U.S. Air Force, maintenance flight line personnel, managed against all challenges and kept the all-weather F-106 operational and ready to defend America against an enemy attack.