Keller retires after 33-year career Published Oct. 2, 2007 GRISSOM AIR RESERVE BASE, Ind -- Master Sgt. John N. Keller of Plymouth, Ind., recently retired from the Air Force Reserve Command after a 33-year career. At the time of his retirement, Sergeant Keller was a flightline expediter with the 434th Air Refueling Wing at Grissom ARB. In this capacity, he played a vital role in helping Grissom ARB keep its KC-135R Stratotanker fleet mission ready. He coordinated various activities to include aircraft launch and recovery, inspections, servicing, and scheduled and unscheduled maintenance. The 434th Air Refueling Wing is the largest KC-135R Stratotanker unit in the Air Force Reserve Command and its aircraft and personnel deploy around the world to support various missions. In his civilian career, Sergeant Keller retired from the United States Postal Service in 2004. He and his wife Lydia reside in Plymouth, Ind.