The T-1A Jayhawk is a medium-range, twin-engine jet trainer used in the advanced phase of Specialized Undergraduate Pilot Training for students selected to fly strategic/tactical airlift or tanker aircraft. It is used also for training Air Force Navigators and Naval Flight Officers in low level flight procedures during the Intermediate Jet phase of training. It replaced the T-39 Saberliner in the Intermediate phase of NFO training.