Horner returned to Nellis AFB in August 1967 where, after initial assignment to the Combat Crew Training Wing, he ended up flying as an instructor at the Fighter Weapons School. In March 1968, he joined the new Fighter Weapons Center at Nellis. From 1970 to 1972 he was assigned as a staff officer to Tactical Air Command (TAC) headquarters at Langley AFB, followed by four months of post-graduate work at the College of William and Mary, where he earned his Master of Business Administration. This was followed by a three-year assignment at The Pentagon and subsequent assignment to the National War College at Seymore Johnson AFB.