United States Air Force parachute riggers are trained at Sheppard AFB in Texas. The career field is classified under "Aircrew Flight Equipment." Airmen attend a 3½-month course learning to inspect, pack, and repair emergency parachutes, as well as a wide variety of other types of aircrew equipment. Once graduated from this technical school, students are assigned to a duty location where they are further instructed using on the job training. USAF aerial delivery riggers (2T2X1) packed training airdrop loads for airlift units. In recent years, Aerial Delivery Air Force riggers have been replaced by contract civilian employees since the mission does not require deployment overseas, and instead consists of supporting training missions at home station.