Graybill retires Published Oct. 25, 2017 By Master Sgt. Eric Amidon 934th Airlift Wing MINNEAPOLIS-ST. PAUL AIR RESERVE STATION, MINN. -- Master Sgt. Mark Graybill receives his retirement certificate from Lt. Col. Edward Buck, 27th Aerial Port Squadron commander, Oct. 15. (Air Force Photo/Master Sgt. Erick Amidon)