sentences:  At Tinker, the wing performed fighter-escort duty training to various SAC B-36 Peacemaker heavy and B-50 medium bomber wings as part of the peacetime readiness training mission of SAC.However, as the new B-47 Stratojet and B-52 Stratofortress bombers came into service, the mission of the fighter-escort wings of SAC became obsolete.The Thunderstreaks simply couldn't keep up with the speed and fly as high as the jet bombers.