The Air National Guard unit in St. Joseph, Missouri, the 139th Ailift, is the home of the Advanced Airlift Tactics Training Center [AATTC], which offers hostile environment training to C-130 crews. The Lockheed C-130 Hercules, a four-engine turboprop aircraft, is the main tactical air transport aircraft of the United States and United Kingdom military forces. Capable of landing and taking off from short, rough dirt runways, it is a personnel and cargo hauler and is used in a wide variety of other roles, such as gunships, weather watchers, tankers, firefighters and aerial ambulances. There are more than 40 versions of the Hercules, and it is widely used by more than 50 nations, establishing a long record of reliability and durability, participating in a variety of military, civilian and humanitarian operations and environments. The H models remains in widespread use with the USAF and many foreign air forces. Initial H model deliveries began in 1964 and remained in production until 1996. An improved C-130H was introduced in 1974. The 139th Airlift Wing, located at Rosencrans Memorial Airport, St. Joseph, MO, flies C-130H Hercules in support of world-wide missions as a reserve component of the Air Mobility Command. The Advanced Airlift Tactics Training Center trains aircrew from all components of the Air Force, Marine Corps, and allied nations, training over 1,000 students in 200. The unit, with nearly 1,000 assigned personnel, has an annual operations and maintenance budget of approximately $25 million.